Birth weight and blood lipid levels in Spanish adolescents: Influence of selected APOE, APOC3 and PPARgamma2 gene polymorphisms. The AVENA Study

1471-2350-9-98 1471-2350 Research article Birth weight and blood lipid levels in Spanish adolescents: Influence of selected APOE, APOC3 and PPARgamma2 gene polymorphisms. The AVENA Study Ruiz R Jonatan ruizj@ugr.es Labayen Idoia idoia.labayen@ehu.es Ortega B Francisco ortegaf@ugr.es Moreno A Luis lmoreno@unizar.es González-Lamuño Domingo pedgfm@humv.es Martí Amelia amarti@unav.es Nova Esther enova@if.csic.es Fuentes García Miguel garciam@medi.unican.es Redondo-Figuero Carlos carlos.redondo@unican.es Martínez J Alfredo jalfmtz@unav.es Sjöström Michael michael.sjostrom@ki.se Castillo J Manuel mcgarzon@ugr.es the AVENA Study Group ruizj@ugr.es

Department of Medical Physiology, School of Medicine, University of Granada, 18071 Granada, Spain

Unit for Preventive Nutrition, Department of Biosciences and Nutrition at NOVUM, Karolinska Institutet, Huddinge, Sweden

Department of Nutrition and Food Science, University of the Basque Country, Vitoria, Spain

E. U. Ciencias de la Salud, University of Zaragoza, Zaragoza, Spain

Department of Pediatrics, University of Cantabria, Santander, Spain

Department of Physiology and Nutrition, University of Navarra, Pamplona, Spain

Immunonutrition Research Group, Department of Metabolism and Nutrition. Consejo Superior de Investigaciones Científicas, Madrid, [E.N.], Spain

BMC Medical Genetics 1471-2350 2008 9 1 98 http://www.biomedcentral.com/1471-2350/9/98 19000312 10.1186/1471-2350-9-98 09 7 2008 10 11 2008 10 11 2008 2008 Ruiz et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Background

There is increasing evidence indicating that genes involved in certain metabolic processes of cardiovascular diseases may be of particular influence in people with low body weight at birth. We examined whether the apolipoprotein (APO) E, APOC3 and the peroxisome proliferator-activated receptor-γ-2 (PPARγ2) polymorphisms influence the association between low birth weight and blood lipid levels in healthy adolescents aged 13–18.5 years.

Methods

A cross-sectional study of 502 Spanish adolescents born at term was conducted. Total (TC) and high density lipoprotein cholesterol (HDLc), triglycerides (TG), apolipoprotein (apo) A and B, and lipoprotein(a) [Lp(a)] were measured. Low density lipoprotein cholesterol (LDLc), TC-HDLc, TC/HDLc and apoB/apoA were calculated.

Results

Low birth weight was associated with higher levels of TC, LDLc, apoB, Lp(a), TC-HDLc, TC/HDLc and apoB/apoA in males with the APOE ε3ε4 genotype, whereas in females, it was associated with lower HDLc and higher TG levels. In males with the APOC3 S1/S2 genotype, low birth weight was associated with lower apoA and higher Lp(a), yet this association was not observed in females. There were no associations between low birth weight and blood lipids in any of the PPARγ2 genotypes.

Conclusion

The results indicate that low birth weight has a deleterious influence on lipid profile particularly in adolescents with the APOE ε3/ε4 genotype. These findings suggest that intrauterine environment interact with the genetic background affecting the lipid profile in later life.

Background

There is increasing evidence indicating that low birth weight is a risk factor for cardiovascular disease. Indeed, among persons born at term, those with lower birth weights have a higher relative risk of metabolic health problems in early adulthood, including hypertension, cardiovascular disease, and type 2 diabetes 1. In this context, findings from the AVENA Study (Alimentación y Valoración del Estado Nutricional en Adolescentes, Food and Nutritional Status in Spanish Adolescents) indicated that birth weight is associated with a number of cardiovascular disease risk factors in adolescents such as total and central body fat, fat free mass, and muscular fitness 2345.

One of the hypotheses explaining this phenomenon is the predisposition to adopt a "thrifty phenotype". According to this theory, fetal adaptation to an adverse intrauterine environment involves programming of pathways that might predispose to metabolic abnormalities and cardiovascular disease in later life. The intra-uterine under- or over-nutrition can alter the gene expression of the fetus, causing developmental adaptations that may lead to permanent changes in physiology and metabolism; changes that may have consequences later in life.

Findings of several cohort studies indicate that low birth weight is associated with adverse plasma lipid profile 678, whereas others have suggested that this association is too small to be considered of public health importance and that other variables as postnatal weight gain could act as confounder of this relationship 9. One would predict that genes involved in the metabolic processes of these diseases may have different effects on people with different body weight at birth. This phenomenon has been described in relation to blood lipids and the apolipoprotein (APO) E gene 10, and both blood lipids and insulin resistance and the peroxisome proliferator-activated receptor-γ-2 (PPARγ2) gene 1112. We have studied the effect of the Ala12 allele in the PPARγ2 gene on the relationship between birth weight and body composition in Spanish adolescents, and we showed that small body weight at birth may program lower fat free mass in adolescents carrying the Ala12 allele 13.

Coronary heart disease is a leading cause of global mortality. The relationship between blood lipids and the development of coronary heart disease in children and adolescents is well established. Results from the AVENA Study showed that 20–30% of Spanish adolescents present an unfavorable blood lipid profile 1415. In the AVENA study, the APOE, APOC3 and PPARγ2 gene polymorphisms were genotyped. The ApoE gene is one of the most important genetic determinants of atherogenesis, since its major function is to regulate the hepatic clearance of triglycerides (TG) rich particles such as chylomicron remnants and very low density lipoprotein remnants. The APOC3 gene have also been proposed as being potentially responsible for the occurrence of lipid profile disturbances, since it has an inhibitory effect on lipoprotein lipase activity and hepatic uptake of lipoproteins 16. Finally, the PPARγ-2 has been shown to enhance lipoprotein TG hydrolysis by endothelial lipoprotein lipase, which in turn seems to affect lipid profile 17.

To understand whether an adverse intrauterine environment may alter the expression of these cardiovascular disease-related genes is clinically relevant. This study aims to clarify to what extent variants of these genes might interact with birth weight in determining the blood lipid profile later in life. Therefore, we examined the influence of APOE, APOC3 and PPARγ2 gene polymorphisms on the association between low birth weight and blood lipid levels in Spanish adolescents from the AVENA Study.

Methods

The AVENA Study is a cross-sectional study designed to assess the nutritional status of a representative sample of Spanish adolescents aged 13 to 18.5 years. Data collection took place from 2000 to 2002 in five Spanish cities (Madrid, Murcia, Granada, Santander and Zaragoza). The complete methodology of the study has been described in detail elsewhere 1518. The number of adolescents included in the AVENA Study was 2859 adolescents. Blood samples and DNA data were randomly obtained from 502 participants. The subgroup from which blood samples were obtained was similar to the remaining subjects regarding the variable selected to calculate the number of participants to be included in the study, i.e. body mass index (BMI) 15, as well as regarding age (P = 0.750) and gender proportions (P = 0.320). A comprehensive verbal description of the nature and purpose of the study was given to the adolescents, their parents and teachers. Written consent to participate was requested from both parents and adolescents. Adolescents with personal history of cardiovascular disease, under medication at the time of the study, or those who were pregnant, were excluded. The study protocol was performed in accordance with the ethical standards laid down in the 1961 Declaration of Helsinki (as revised in Hong-Kong in 1989, and in Edinburgh in 2000), and approved by the Review Committee for Research Involving Human Subjects of the Hospital Universitario Marqués de Valdecilla (Santander, Spain).

Before any testing was performed, the parents completed a questionnaire, part of which addressed the adolescents' previous and current health status. Socioeconomic status was also assessed via the questionnaire, and was defined by the educational level and occupation of the father. According to this information, and following the recommendation of the Spanish Society for Epidemiology, the adolescents were classified into five categories: low (I), medium-low (II), medium (III), medium-high (IV) and high socioeconomic status (V).

Neonatal data

Data on birth weight and gestational age at birth were obtained from health booklets records that are issued at birth and where child's paediatricians records birth weight, charts the infant's growth and vaccinations. Birth weight was expressed as the standard deviation from the expected weight calculated with the use of reference standards previously described for this population, according to sex and gestational age 19. This variable (called birth weight score) will be used for the analyses.

Gestational age was coded as 1 for those who were born between the 35^thto 40^thweek of gestation, and 2 for those who were born after the 40^thweek of gestation. According to this information, 80.9% and 77.0% of males and females, respectively, were born between 35 to 40 weeks of gestation, and 12.2% of males and 15.1% of females were born after more than 40 weeks of gestation. The percentage of adolescents born before 35 weeks of gestation was 6.9% of the males and 7.9% of the females. This group was not included in the analyses.

Physical examination

Anthropometric measurements were obtained as described elsewhere 2021. BMI was calculated as weight in kilograms divided by square of height in meters (kg/m²). Skinfold thickness was measured at the biceps, triceps, subscapular, suprailiac, thigh and calf on the left side of the body to the nearest 0.2 mm using a Holtain skinfold caliper. Body fat percentage was calculated from skinfold thicknesses (triceps and subscapular) using Slaughter's equations 22, and fat free mass (kg) was derived by subtracting fat mass from total body weight. Reference values for anthropometric measurements of the AVENA Study can be found elsewhere 2021.

Identification of pubertal development was assessed according to Tanner & Whitehouse 23. Self-reported genital development in males and breast development in females were used for pubertal stage classification.

Cardiorespiratory fitness

Cardiorespiratory fitness was assessed by the 20 m shuttle run test as previously described 24. It was considered as the number of stages completed (precision of 0.5 steps). All participants were familiarized with the test, since the 20 m shuttle run test is one of the fitness tests included in the physical education curriculum in our country. Reference values of fitness levels have been reported for the whole study population as well as for those adolescents from whom blood sample was obtained 25.

Blood sampling

Blood (20 ml) was collected from an antecubital vein between 8:00 and 9:00 a.m, after an overnight fast. Serum levels of total (TC) and high density lipoprotein cholesterol (HDLc), as well as the levels of TG, apolipoprotein (apo)A and B, and lipoprotein(a) [Lp(a)] were measured. The coefficients of variation were less than 3% and the intra-class coefficients were higher than 0.96% for all blood variables. Quality control of the assays was assured by the Regional Health Authority, as is compulsory for all hospital clinical laboratories in Spain.

Low density lipoprotein cholesterol (LDLc) was calculated with the Friedewald formula 26. The following atherogenic indices were also calculated: TC-HDLc, TC/HDLc, and apoB/apoA. A detailed description of the blood analysis as well as reference values for lipid and lipoprotein has been reported by Ruiz et al. 1527.

Genotyping

Genomic DNA was extracted and purified from 500 μL of whole blood treated with EDTA, using the Quiagen procedure described by Higuchi 28. APOE genotypes were determined by polymerase chain reaction (PCR) and allele-specific restriction digestion of the amplified products with the restriction enzyme HhaI, as described elsewhere 29 (rs7412, and rs429358). APOE genotypes were encoded as 1 = ε2/ε3, 2 = ε3/ε3, and 3 = ε3/ε4. APOC3 genotypes were determined by PCR and allele-specific restriction digestion of the amplified products with the restriction enzyme SstI following the procedures described elsewhere 30. APOC3 genotypes were encoded as 1 = S1/S1 and 2 = S1/S2 (rs5128). The PPARγ2 genotypes were determined by the PCR method and further digestion of products with BstU-I restriction enzymes as previously described 31, and were encoded as 1 = Pro12/Pro, and 2 = Pro12/Ala and Ala12/Ala genotype 32 (rs1801282). The percentage of adolescents with the Ala12/Ala genotype was 1.3%, therefore this sub-group was analyzed together with the Pro12/Ala.

Statistical analysis

Following a bivariate correlation analysis, multiple regressions were used to study the association between birth weight and blood lipid levels, for males and females separately (unadjusted model). Further analyses were done after controlling for age, pubertal stage, socioeconomic status, gestational age, BMI and cardiorespiratory fitness (adjusted model). A separate regression model was performed for each lipid parameter. Additional analyses were also performed by genotypes.

To stabilize variability and to achieve normality in the residuals, TC, HDLc, LDLc, TG, apoA, apoB and Lp(a) were transformed to the natural logarithm.

The impact on blood lipid levels of APOE, APOC3 and PPARγ2 genotypes was analyzed by one-way analysis of variance (ANOVA), for males and females separately. For the APOE genotypes, the subgroup means were compared by Tukey's test. Comparisons were adjusted for mass significance as described by Holm 3334. The method of Holm proceeds as follows: Sort the P-values of the k tests in increasing order, P₁, P₂, ..., P_i, ..., P_k. If P₁> α/k; none of the k tests are significant, and the test procedure is finished. If P₁≤ α/k, test 1 is significant, and now P₂is examined. If P₂> α/(k - 1), none of the (k - 1) remaining tests are significant, but if P₂≤ α/(k - 1), test 2 is significant and P₃is examined. This procedure goes on until P_i> α/(k - i + 1), and the procedure is interrupted. This method keeps family error rate less than α. Family error rate is defined as the probability that one or more false significances out of k tests is less than or equal to α.

Interaction effects between birth weight and sex, and between birth weight and genotypes were tested by inserting product terms for the relevant variables. The analyses were performed using the Statistical Package for Social Sciences (SPSS, v. 15.0 for WINDOWS; SPSS Inc, Chicago) and the level of significance was set to 0.05.

Results

Descriptive characteristics of the study sample are shown in Table 1.

Table 1

Descriptive characteristics of the study sample

Males (n = 260)

Females (n = 242)

Age (years)

15.4 ± 1.4

Tanner II,III,IV,V (%)

5.8, 15.1, 41.8, 37.3

1.6, 8.1, 54.3, 36.0

Weight (kg)

64.6 ± 13.4

56.8 ± 10.5

Height (cm)

170.7 ± 8.2

161.5 ± 6.4

Body mass index (kg/m²)

22.1 ± 3.9

21.7 ± 3.5

Cardiorespiratory fitness (stage)

7.0 ± 2.6

4.1 ± 1.8

Sum of 6 skinfolds

75.8 ± 38.1

98.8 ± 31.9

Percentage body fat

20.2 ± 10.4

25.6 ± 6.6

Triglycerides (mg/dl)

71.3 ± 31.6

64.7 ± 26.4

TC (mg/dl)

156.7 ± 26.4

169.9 ± 26.4

HDLc (mg/dl)

51.0 ± 9.7

59.2 ± 11.6

LDLc (mg/dl)

91.4 ± 23.9

97.4 ± 23.2

ApoA (mg/dl)

116.9 ± 17.1

127.7 ± 19.2

ApoB (mg/dl)

66.9 ± 14.3

69.9 ± 13.8

Lp(a) (mg/dl)*

14.1 ± 4.2

5.3 ± 3.9

ApoA/ApoB (mg/dl)

1.8 ± 0.5

1.9 ± 0.5

TC-HDLc (mg/dl)

105.7 ± 25.9

110.6 ± 25.8

Birth weight (g)

3443.0 ± 539.0

3283 ± 564

Birth weight score

409.0 ± 516.0

353 ± 559

Socieconomic status I,II,III,IV,V (%)

5.9, 25.3, 41.6, 23.6, 3.6

7.2, 25.4, 37.1, 23.3, 6.9

Values are means ± SD, otherwise indicated.

TC indicates total cholesterol; HDLc, high density liprotein cholesterol; LDLc, low density lipoprotein cholesterol; TG, triglycerides; Apo, apolipoprotein; Lp(a), lipoprotein a.

*Geometric mean ± SD.

Interactions

There was a significant (all P < 0.05) interaction effect between birth weight and sex in all the outcome variables, therefore, all the analyses were performed separately for males and females. There was a significant interaction effect between birth weight and APOE in all of the outcome variables (TC, P = 0.02; HDL, P = 0.021; LDLc, P = 0.001; apoA, P = 0.049; apoB, P = 0.01; Lp(a), P = 0.051; TC-HDLc, P = 0.025; apoB/apoA, P = 0.054), except for TG (P = 0.362). There was also a significant interaction effect between birth weight and APOC3 (for TG, P = 0.025; apoA, P = 0.038, and Lp(a), P = 0.002). No significant (all P > 0.1) interaction effect between birth weight and PPARγ2 was found.

Birth weight and lipids

In males, low birth weight was associated with lower levels of HDLc and apoA, and higher TC/HDLc and apoB/apoA ratios (Figure 1). Birth weight was not significantly associated with blood lipids in females. The results were similar after controlling for age, pubertal stage, socioeconomic status, gestational age, BMI and cardiorespiratory fitness (Table 2).

Table 2

Regression coefficients (β^ MathType@MTEF@5@5@+=feaagaart1ev2aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacPC6xNi=xH8viVGI8Gi=hEeeu0xXdbba9frFj0xb9qqpG0dXdb9aspeI8k8fiI+fsY=rqGqVepae9pg0db9vqaiVgFr0xfr=xfr=xc9adbaqaaeGaciGaaiaabeqaaeqabiWaaaGcbaGafqOSdiMbaKaaaaa@2D86@) showing the association between birth weight score and blood lipid and lipoprotein levels by sex after controlling for age, pubertal stage, socioeconomic status, gestational age, body mass index and cardiorespiratory fitness

Males (n = 260)

Females (n = 242)

β ^ MathType@MTEF@5@5@+=feaagaart1ev2aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacPC6xNi=xH8viVGI8Gi=hEeeu0xXdbba9frFj0xb9qqpG0dXdb9aspeI8k8fiI+fsY=rqGqVepae9pg0db9vqaiVgFr0xfr=xfr=xc9adbaqaaeGaciGaaiaabeqaaeqabiWaaaGcbaGafqOSdiMbaKaaaaa@2D86@

P value

TC*

0.035

0.682

0.073

0.476

HDLc*

0.134

0.009

0.058

0.537

LDLc*

-0.051

0.549

-0.044

0.668

TG*

-0.017

0.841

-0.06

0.541

apoA*

0.187

<0.001

-0.025

0.784

apoB*

-0.031

0.723

0.032

0.749

Lp(a)*

-0.085

0.334

0.051

0.614

TC-HDLc

-0.026

0.76

0.044

0.668

TC/HDLc

-0.066

0.003

-0.001

0.991

apoB/apoA

-0.113

0.029

0.049

0.609

TC indicates total cholesterol; HDLc, high density liprotein cholesterol; LDLc, low density lipoprotein cholesterol; TG, triglycerides; Apo, apolipoprotein; Lp(a), lipoprotein a.

*Analyses were performed on log transformed data.

Figure 1

Birth weight score (g) and blood lipid and lipoprotein levels (mg/dl) in male adolescents

Birth weight score (g) and blood lipid and lipoprotein levels (mg/dl) in male adolescents. HDLc indicates high density lipoprotein cholesterol; apo, apolipoprotein; TC, total cholesterol.

Genotypes and lipids

All the genotype frequencies of the analyzed gene polymorphism were in agreement with the Hardy-Weinberg equilibrium. The distribution of the APOE genotypes did not differ between males and females (P = 0.961) (Table 3). Males with the ε2ε3 genotype had lower levels of TC, LDLc and apoB compared with those with the ε3ε3 genotype. Similarly, females with the ε2ε3 genotype had lower levels of LDLc, and apoB compared with those with the ε3ε3 genotype. Females with ε2ε3 genotype had higher levels of apoA compared with those with the ε3ε3 genotype. There were no subjects with the ε2ε2, ε2ε4 or the ε4ε4 genotype.

Table 3

Lipid and lipoprotein levels (mg/dl), and body mass index (kg/m²) according to the APOE genotypes and sex

Males (n = 260)

Females (n = 242)

Genotype

ε2/ε3

ε3/ε3

ε3/ε4

P value

ε2/ε3

ε3/ε3

ε3/ε4

P value

n (%)

22 (8.5)

186 (71.6)

52 (19.9)

21 (8.5)

175 (72.6)

46 (18.9)

TC**

144.2* ± 34.4

157.9 ± 24.8

160.6 ± 26.8

<0.05

160.8 ± 24.7

169.1 ± 25.1

177.0 ± 30.8

HDLc**

53.0 ± 8.6

51.4 ± 9.6

49.8 ± 10.3

65.5* ± 11.1

58.6 ± 11.0

58.5 ± 13.1

LDLc**

77.2^†± 28.6

92.7 ± 22.9

95.3 ± 23.8

<0.01

83.2^†± 24.7

97.5 ± 21.9

103.4 ± 26.1

<0.01

TG**

69.7 ± 28.7

69.4 ± 28.1

77.5 ± 39.0

60.4 ± 22.1

64.4 ± 26.1

68.0 ± 30.0

apoA**

115.9 ± 15.6

118.1 ± 17.3

114.5 ± 16.3

141.7^†± 15.6

125.7 ± 17.9

128.9 ± 23.3

<0.01

apoB**

55.6^†± 15.8

68.0 ± 13.0

68.8 ± 16.4

<0.001

59.3^†± 11.7

70.1 ± 12.9

73.9 ± 16.1

<0.001

Lp(a)**

23.1 ± 33.4

31.0 ± 35.1

33.1 ± 41.9

14.3 ± 15.3

33.0 ± 40.3

37.6 ± 38.5

TC-HDLc

91.1* ± 31.6

106.6 ± 24.3

110.8 ± 27.7

<0.01

95.3* ± 25.5

110.4 ± 24.0

118.5 ± 30.5

<0.01

TC/HDLc

2.7* ± 0.7

3.2 ± 0.7

3.4 ± 0.9

<0.01

2.5* ± 0.7

3.0 ± 0.6

3.1 ± 0.8

<0.01

apoB/apoA

0.5* ± 0.1

0.6 ± 0.1

0.6 ± 0.2

<0.01

0.4^†± 0.1

0.6 ± 0.1

0.6 ± 0.2

<0.001

BMI

20.9 ± 3.9

22.2 ± 3.8

22.4 ± 4.0

21.5 ± 3.9

21.7 ± 3.6

21.8 ± 3.4

Values are expressed as mean ± standard deviation, otherwise stated.

P value from ANOVA, adjusted for mass significance.

*P < 0.05; ^†P < 0.01 for ε2/ε3 vs ε3/ε3 (Tukey test).

TC indicates total cholesterol; HDLc, high density liprotein cholesterol; LDLc, low density lipoprotein cholesterol; TG, triglycerides; Apo, apolipoprotein; Lp(a), lipoprotein (a); BMI, body mass index; NS, not significant.

**Analyses were performed on log transformed data, but non-transformed data are presented in the table.

The distribution of the APOC3 genotypes did not differ between males and females (P = 0.489) (Table 4). In males, levels of blood lipid were similar between S1/S1 and S1/S2 genotypes, whereas in females, adolescents with the S1/S1 genotype had lower levels of TC and TC-HCLc compared with those with the S1/S2 genotype.

Table 4

Lipid and lipoprotein levels (mg/dl) and body mass index (kg/m²) according to the APOC3 genotypes and sex

Males (n = 260)

Females (n = 242)

Genotype

S1/S1

S1/S2

P value

S1/S1

S1/S2

P value

n (%)

214 (82.1)

46 (17.0)

198 (81.8)

44 (18.2)

TC*

156.2 ± 26.4

159.7 ± 27.0

167.2 ± 25.2

181.9 ± 28.9

<0.001

HDLc*

51.0 ± 9.4

51.1 ± 11.4

59.0 ± 11.4

60.0 ± 12.0

LDLc*

91.1 ± 23.7

93.3 ± 25.2

95.5 ± 22.4

106.3 ± 25.7

TG*

70.5 ± 31.7

76.1 ± 31.3

63.5 ± 26.1

70.6 ± 27.8

apoA*

117.6 ± 17.2

114.1 ± 16.5

127.0 ± 19.5

130.2 ± 18.1

apoB*

66.6 ± 14.4

68.4 ± 14.0

68.8 ± 13.1

74.9 ± 16.1

Lp(a)*

31.2 ± 37.1

27.9 ± 32.4

32.5 ± 39.4

31.8 ± 36.8

TC-HDLc

105.2 ± 25.7

108.6 ± 27.0

108.2 ± 23.9

121.8 ± 31.4

<0.01

TC/HDLc

3.2 ± 0.7

3.3 ± 0.8

2.9 ± 0.6

3.2 ± 0.9

apoB/apoA

0.6 ± 0.1

0.6 ± 0.2

0.6 ± 0.1

0.6 ± 0.2

BMI

22.1 ± 3.9

22.2 ± 3.8

21.5 ± 3.4

22.6 ± 4.0

Values are expressed as mean ± standard deviation, otherwise stated.

P value from ANOVA, adjusted for mass significance.

*Analyses were performed on log transformed data, but non-transformed data are presented in the table.

The distribution of the PPARγ2 genotypes did not differ between males and females (Pro12/Pro, 85 and 82% in males and females, respectively; Pro12/Ala, 15 and 18%, in males and females, respectively). No differences were found between the Pro12/Pro and Pro12/Ala12 genotypes in any of the lipid parameters studied, nor in BMI (data not shown).

There were no differences between all the genotypes in birth weight in males and females. The outcome did not change when all the analyses were adjusted for age and/or pubertal development.

Birth weight, lipids and genotype interactions

Low birth weight was associated with higher levels of TC, LDLc, apoB, Lp(a), TC-HDLc, TC/HDLc and apoB/apoA in males with the APOE ε3ε4 genotype, after controlling for age, pubertal status, socioeconomic status, gestational age, BMI and cardiorespiratory fitness (Table 5). Low birth weight was also associated with lower levels of HDLc and apoA in males with the APOE ε3ε3 genotype. In females with the APOE ε3ε4 genotype, low birth weight was associated with lower levels of HDLc and higher levels of TG. Low birth weight was not significantly associated with any of the lipid parameters studied in those adolescents with the APOE ε2ε3 or in females with the ε3ε3 genotype.

Table 5

Regression coefficients (β^ MathType@MTEF@5@5@+=feaagaart1ev2aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacPC6xNi=xH8viVGI8Gi=hEeeu0xXdbba9frFj0xb9qqpG0dXdb9aspeI8k8fiI+fsY=rqGqVepae9pg0db9vqaiVgFr0xfr=xfr=xc9adbaqaaeGaciGaaiaabeqaaeqabiWaaaGcbaGafqOSdiMbaKaaaaa@2D86@) showing the association between birth weight score and lipid and lipoprotein levels by APOE genotypes and sex after controlling for age, pubertal stage, socioeconomic status, gestational age, body mass index and cardiorespiratory fitness

Males (n = 260)

Females (n = 242)

ε2/ε3

ε3/ε3

ε3/ε4

ε2/ε3

ε3/ε3

ε3/ε4

P value

TC*

0.019

0.976

0.198

0.065

-0.401

0.042

0.787

0.353

0.157

0.197

-0.313

0.262

HDLc*

0.487

0.242

0.285

0.011

0.262

0.238

0.797

0.427

0.153

0.195

0.525

0.027

LDLc*

-0.109

0.787

0.121

0.260

-0.622

0.003

0.458

0.566

0.116

0.354

-0.302

0.264

TG*

-0.023

0.956

0.001

0.988

0.048

0.824

0.610

0.031

-0.153

0.171

-0.477

0.039

apoA*

0.424

0.326

0.236

0.022

0.328

0.125

0.698

0.314

0.150

0.900

-0.267

0.278

apoB*

-0.092

0.820

0.160

0.145

-0.554

0.008

0.428

0.540

-0.172

0.172

-0.076

0.780

Lp(a)*

-0.064

0.863

0.122

0.259

-0.625

0.002

-0.301

0.743

0.054

0.667

0.054

0.843

TC-HDLc

-0.019

0.663

0.127

0.227

-0.454

0.024

0.518

0.522

0.085

0.501

-0.060

0.816

TC/HDLc

-0.402

0.286

0.014

0.889

-0.406

0.028

0.106

0.900

-0.041

0.742

0.243

0.291

apoB/apoA

-0.333

0.387

-0.007

0.946

-0.518

0.011

0.142

0.850

0.047

0.699

0.130

0.588

TC indicates total cholesterol; HDLc, high density liprotein cholesterol; LDLc, low density lipoprotein cholesterol; TG, triglycerides; Apo, apolipoprotein; Lp(a), lipoprotein a.

*Analyses were performed on log transformed data.

Low birth weight was associated with lower levels of apoA in males with the APOC3 S1/S1 genotype, and higher levels of Lp(a) in those with both the APOC3 S1/S1 and the S1/S2 genotype. In females, low birth weight was not significantly associated with blood lipids in any of the APOC3 genotypes (Table 6). There were no associations between low birth weight and blood lipids in any of the PPARγ2 genotypes (data not shown). The outcome did not change when BMI was not included in the model. The results did not materially change either when another anthropometric index (i.e. sum of six skinfold thicknesses, percentage of body fat, fat free mass, waist circumference, height squared) rather than BMI was included in the model.

Table 6

Regression coefficients (β^ MathType@MTEF@5@5@+=feaagaart1ev2aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacPC6xNi=xH8viVGI8Gi=hEeeu0xXdbba9frFj0xb9qqpG0dXdb9aspeI8k8fiI+fsY=rqGqVepae9pg0db9vqaiVgFr0xfr=xfr=xc9adbaqaaeGaciGaaiaabeqaaeqabiWaaaGcbaGafqOSdiMbaKaaaaa@2D86@) showing the association between birth weight score and lipid and lipoprotein levels by APOC3 genotypes and sex after controlling for age, pubertal stage, socioeconomic status, gestational age, body mass index and cardiorespiratory fitness

Males (n = 260)

Females (n = 242)

S1/S1

S1/S2

S1/S1

S1/S2

P value

TC*

0.050

0.609

-0.301

0.211

0.032

0.795

-0.309

0.535

HDLc*

0.184

0.053

-0.148

0.493

-0.063

0.590

0.363

0.346

LDLc*

-0.089

0.360

-0.208

0.387

-0.002

0.987

-0.305

0.528

TG*

0.048

0.616

-0.190

0.405

0.188

0.113

-0.588

0.227

apoA*

0.244

0.010

-0.146

0.522

-0.120

0.279

0.281

0.456

apoB*

-0.043

0.668

-0.267

0.268

0.022

0.859

-0.330

0.469

Lp(a)*

-0.294

0.003

-0.731

<0.001

0.021

0.865

0.020

0.867

TC-HDLc

0.022

0.871

-0.278

0.277

0.050

0.682

-0.409

0.394

TC/HDLc

-0.086

0.355

-0.087

0.722

0.097

0.407

-0.433

0.338

apoB/apoA

-0.144

0.130

-0.166

0.504

0.108

0.351

-0.377

0.367

TC indicates total cholesterol; HDLc, high density liprotein cholesterol; LDLc, low density lipoprotein cholesterol; TG, triglycerides; Apo, apolipoprotein; Lp(a), lipoprotein a.

*Analyses were performed on log transformed data.

Discussion

The results of the present study show that low birth weight seems to have a deleterious influence on blood lipid profile, particularly in those adolescents with the APOE ε3/ε4 genotype. The results also suggest that low birth weight is associated with lower levels of HDLc and apoA, and higher TC/HDLc and apoB/apoA ratios in male adolescents. Yet, low birth weight is not associated with blood lipid levels in female adolescents. Out of the three genes analyzed, the APOE genotypes seem to be a major determinant factor of lipid and lipoprotein profile in both sexes. Taken together, these results support the notion that intrauterine environment interact with genes in determining blood lipid profile in later life. One possible explanation to these findings is that a reduced foetal growth may have negative consequences on the liver growth. A poor liver growth may cause a down-regulation of the hepatic receptors, as well as disturbances in the synthesis of cholesterol. Consequently, the influence of the APOE genotypes on the lipid and lipoprotein metabolism would be intensified in those individuals with a low birth weight.

The potential underlying mechanism linking low birth weight with and adverse lipid profile in later life remains unclear. Barker et al. 7 suggested that raised serum TC, LDLc, and apoB levels in adult life might be associated with impaired growth during late gestation, when fetal undernutrition has a disproportionate effect on liver growth. Therefore, as the liver regulates lipid metabolism, impaired in utero growth of the liver may program a more adverse lipid profile.

Interpretation of the birth weight effect on blood lipids after adjustment for current body size is controversial, and available results indicate that postnatal changes in size, rather than fetal growth, is important 35. Our findings show that the influence of low birth weight on HDLc, apoA, TC/HDLc and apoB/apoA in males was not altered after controlling for any of the measures of current body size or by others potential confounders such as age 15, pubertal maturation 27, cardiorespiratory fitness 1436 or socioeconomic status 37. It is noteworthy that the associations between birth weight and blood lipids were mainly observed in males. A number of studies have found evidences for a sex related difference in the programming effect of low birth weight and later cardiovascular risk factors 338. Sex related differences in the association between fetal growth and later coronary heart disease risk suggest that male fetuses are more vulnerable to the effects of fetal undernutrition 38. One of the explanations lays on the fact that male fetuses seem to grow at a faster rate than female foetuses 3940. Therefore, assuming that fetal nutritional programming is the primary pathway for the association between birth weight and later cardiovascular disease risk factors it could be expected these associations to be stronger in males compared to females 3940. Our results concur with those showed in a meta-analyses by Lawlor et al. 38. They reported that the association between birth weight and total cholesterol was stronger in males compared to females. The biological explanation for the different outcomes obtained in males and females warrant further investigation. It has been reported that the influence of sex on genes involved in the lipid and glucose metabolism could be attributed to hormonal differences 4142. However, we did not measure sex hormones, which hamper a further study of hormone-lipoprotein relationships in the studied population.

Variation in blood lipid levels seems to be partially determined by the APOE genotypes 10, which agree with our data. APOE genotype has also been shown to affect the association between birth weight and blood lipids in children 10. Garces et al. reported that a greater effect of the APOE genotype on TC, LDLc and apoB levels was found in children with low birth weight 10. In our study, low birth weight was associated with higher levels of TC and LDLc, apoB, and Lp(a) in males with the APOE ε3/ε4 genotype. Likewise, low birth weight was also associated with higher apoB/apoA ratio, which is a strong cardiovascular risk factor 43. This observation suggests that the interaction of APOE genotype and birth weight might be an important determinant for future atherosclerosis.

Female adolescents with the APOC3 S1/S2 genotype had elevated TC and non-HDLc levels, which is in agreement with another study 44. The levels of triglyceride were similar between S1/S1 and S1/S2 genotypes in both males and females as reported in other population samples 4546. We also found that low birth weight was associated with lower levels of apoA in males with the APOC3 S1/S1 genotype, whereas low birth weight was associated with higher levels of Lp(a) in males with both S1/S1 and S1/S2 genotypes. This is the first study examining the influence of this polymorphism on the association between low birth weight and blood lipid levels in adolescents.

The PPARγ2 gene plays an important role in the regulation of glucose, lipid and energy metabolism 47, therefore it would be expected that the PPARγ2 genotypes could affect circulating lipid levels. The findings concerning the associations between PPARγ2 genotypes and lipid levels are contradictory 1141484950. We did not find differences on blood lipid and lipoprotein levels between genotypes, nor did on birth weight. Pfab et al. reported that neither the fetal nor the maternal PPARγ2 genotypes affected the birth weight of the 1950 newborn studied 50. There is one study underlying the influence of PPARγ2 genotypes on the association between birth weight and lipid levels among elderly people 11. It was reported that the Ala12 allele was associated with an increased TC, LDLc, and non-HDLc levels only among those who had birth weights lower than 3000 g. We did not find a significant effect of birth weight on lipid levels regarding the analyzed PPARγ2 genotypes, which agree with others 50.

Other factors such as current dietary intake may have affected the lipid levels, but such data were not available in the AVENA Study. There is controversy about the influence of age at the onset of menses on lipid and lipoprotein levels. Yet, no effect of age of menarche on lipid levels have been observed in the AVENA Study population 15. The inclusion of age of menarche in the analysis rather than pubertal status did not alter the outcome. Birth weight might be a crude marker of the influence of maternal environment on fetal development and therefore underestimate the influence of such factors on offspring health outcomes. Future studies should directly measure potentially modifiable factors such as maternal nutrition, smoking, alcohol consumption or exercise, and relate these to offspring cardiovascular disease risk factors. It also remains possible that other birth measures including ponderal index, head circumference of waist circumference could be more important, but these measures were not available in the present study. The results should be interpreted with caution due to the small sample sizes.

Conclusion

The results of this study suggest that intrauterine environment interact with the genetic background affecting the lipid profile in later life. The findings indicate that low birth weight has a deleterious influence on lipid profile particularly in adolescents with the APOE ε3/ε4 genotype.

Competing interests

The authors declare that they have no competing interests. No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article.

Authors' contributions

JRR conceived the hypothesis, conducted the statistical analyses, and drafted the manuscript. IL, FOP and LAM critically revised the drafted manuscript. DGL, AM, MGF, JAM performed the genetic analysis. All authors contributed to the interpretation and discussion of the results, and critically revised the drafted manuscript.

Note

*AVENA Study Group

Coordinator: A Marcos, Madrid.

Local coordinators:

MJ Castillo, Granada.

A Marcos, Madrid.

S Zamora, Murcia.

M García Fuentes, Santander.

M Bueno, Zaragoza, Spain.

Granada: MJ Castillo, MD Cano, R Sola (Biochemistry); A Gutiérrez, JL Mesa, JR Ruiz (Physical fitness); M Delgado, P Tercedor, P Chillón (Physical activity), M Martín, F Carreño, FB Ortega, GV Rodríguez, R Castillo, F Arellano (Collaborators). Universidad de Granada. E-18071 Granada.

Madrid: A Marcos, M González-Gross, J Wärnberg, S Medina, F Sánchez Muniz, E Nova, A Montero, B de la Rosa, S Gómez, S Samartín, J Romeo, R Álvarez, (Coordination, immunology) A Álvarez (Cytometric analysis) L Barrios (Statistical analysis) A Leyva, B Payá (Psychological assessment). L Martínez, E Ramos, R Ortiz, A Urzanqui. (Collaborators). Instituto de Nutrición y Bromatología. Consejo Superior de Investigaciones Científicas (CSIC). E-28040 Madrid.

Murcia: S Zamora, M Garaulet, F Pérez-Llamas, JC Baraza, JF Marín, F Pérez de Heredia, MA Fernández, C González, R García, C Torralba, E Donat, E Morales, MD García, JA Martínez, JJ Hernández, A Asensio, FJ Plaza, MJ López (Diet analysis). Dpto. Fisiología. Universidad de Murcia. E-30100 Murcia.

Santander: M García Fuentes, D González-Lamuño, P de Rufino, R Pérez-Prieto, D Fernández, T Amigo (Genetic study). Dpto. Pediatría. Universidad de Cantabria. E – 19003 Santander.

Zaragoza: M Bueno, LA Moreno, A Sarriá, J Fleta, G Rodríguez, CM Gil, MI Mesana, JA Casajús, Vicente Blay, María Guadalupe Blay. (Anthropometric assessment). Escuela Universitaria de Ciencias de la Salud. Universidad de Zaragoza. E-50009 Zaragoza.

Acknowledgements

The AVENA study was supported by the Spanish Ministry of Health Instituto de Salud Carlos III (FIS PI021830), the Spanish Ministry of Health, FEDER-FSE funds FIS n° 00/0015, CSD grants 05/UPB32/0, 109/UPB31/03 and 13/UPB20/04, the Spanish Ministry of Education (AP-2004-2745; EX-2007-1124), scholarships from Panrico S.A., Madaus S.A. and Procter and Gamble S.A.

Fetal origins of adult disease: strength of effects and biological basis Barker DJ Eriksson JG Forsen T Osmond C Int J Epidemiol 2002 31 6 1235 1239 10.1093/ije/31.6.1235 12540728 Small birth weight and later body composition and fat distribution in adolescents: the Avena study Labayen I Moreno LA Ruiz JR Gonzalez-Gross M Warnberg J Breidenassel C Ortega FB Marcos A Bueno M Obesity (Silver Spring) 2008 16 7 1680 1686 10.1038/oby.2008.258 18464751 Early programming of body composition and fat distribution in adolescents Labayen I Moreno LA Blay MG Blay VA Mesana MI Gonzalez-Gross M Bueno G Sarria A Bueno M J Nutr 2006 136 1 147 152 16365074 High fitness is associated with a healthier programming of body composition at adolescence Ortega FB Ruiz JR Labayen I Redondo C Breidenassel C Gomez S Moreno LA Castillo MJ Am J Hum Biol 2008 Are Muscular and Cardiovascular Fitness Partially Programmed at Birth? Role of Body Composition Ortega FB Labayen I Ruiz JR Martin-Matillas M Vicente-Rodriguez G Redondo C Warnberg J Gutierrez A Sjostrom M Castillo MJ J Pediatr 2008 18783796 Impaired fetal growth and atherosclerosis of carotid and peripheral arteries Martyn CN Gale CR Jespersen S Sherriff SB Lancet 1998 352 173 178 10.1016/S0140-6736(97)10404-4 9683205 Growth in utero and serum cholesterol concentrations in adult life Barker DJ Martyn CN Osmond C Hales CN Fall CH Bmj 1993 307 6918 1524 1527 1679540 8274921 Birth weight, childhood growth, and cardiovascular disease risk factors in Japanese aged 20 years Miura K Nakagawa H Tabata M Morikawa Y Nishijo M Kagamimori S Am J Epidemiol 2001 153 8 783 789 10.1093/aje/153.8.783 11296151 Birth weight and blood cholesterol level: a study in adolescents and systematic review Owen CG Whincup PH Odoki K Gilg JA Cook DG Pediatrics 2003 111 5 Pt 1 1081 1089 10.1542/peds.111.5.1081 12728092 Influence of birth weight on the apo E genetic determinants of plasma lipid levels in children Garces C Benavente M Ortega H Rubio R Lasuncion MA Rodriguez Artalejo F Fernandez Pardo J de Oya M Pediatr Res 2002 52 6 873 878 10.1203/01.PDR.0000037140.57784.8B 12438664 The effects of the Pro12Ala polymorphism of the PPARgamma-2 gene on lipid metabolism interact with body size at birth Eriksson J Lindi V Uusitupa M Forsen T Laakso M Osmond C Barker D Clin Genet 2003 64 4 366 370 10.1034/j.1399-0004.2003.00150.x 12974743 The effects of the Pro12Ala polymorphism of the peroxisome proliferator-activated receptor-gamma2 gene on insulin sensitivity and insulin metabolism interact with size at birth Eriksson JG Lindi V Uusitupa M Forsen TJ Laakso M Osmond C Barker DJ Diabetes 2002 51 7 2321 2324 10.2337/diabetes.51.7.2321 12086968 Effect of the Ala12 allele in the PPARgamma-2 gene on the relationship between birth weight and body composition in adolescents: the AVENA study Labayen I Moreno LA Marti A Gonzalez-Lamuno D Warnberg J Ortega FB Bueno G Nova E Ruiz JR Garagorri JM Pediatr Res 2007 62 5 615 619 17805195 A mediterranean diet is not enough for health: physical fitness is an important additional contributor to health for the adults of tomorrow Castillo-Garzon M Ruiz JR Ortega FB Gutierrez-Sainz A World Rev Nutr Diet 2007 97 114 138 17167292 Serum lipid and lipoprotein reference values of Spanish adolescents; The AVENA study Ruiz JR Ortega FB Moreno LA Wärnberg J Gonzalez-Gross M Cano MD Gutierrez A Castillo MJ the AVENA Study Group Soz Praventivmed 2006 51 99 109 10.1007/s00038-005-0021-9 18027788 Inhibition of lipoprotein lipase activity by synthetic peptides of apolipoprotein C-III McConathy WJ Gesquiere JC Bass H Tartar A Fruchart JC Wang CS J Lipid Res 1992 33 7 995 1003 1431591 PPAR gamma and human metabolic disease Semple RK Chatterjee VK O'Rahilly S J Clin Invest 2006 116 3 581 589 1386124 16511590 10.1172/JCI28003 Alimentacion y valoracion del estado nutricional de los adolescentes espanoles (estudio AVENA). Evaluacion de riesgos y propuesta de intervencion. I. descripcion metodologica del proyecto Gonzalez-Gross M Castillo MJ Moreno L Nova E Gonzalez-Lamuno D Perez-Llamas F Gutierrez A Garaulet M Joyanes M Leiva A Nutricion Hospitalaria 2003 18 1 15 28 12621808 Gender differences in newborn subcutaneous fat distribution Rodriguez G Samper MP Ventura P Moreno LA Olivares JL Perez-Gonzalez JM Eur J Pediatr 2004 163 8 457 461 10.1007/s00431-004-1468-z 15168110 Overweight, obesity and body fat composition in spanish adolescents. The AVENA Study Moreno LA Mesana MI Fleta J Ruiz JR Gonzalez-Gross M Sarria A Marcos A Bueno M Group AS Ann Nutr Metab 2005 49 2 71 76 10.1159/000084738 15802900 Anthropometric body fat composition reference values in Spanish adolescents. The AVENA Study Moreno LA Mesana MI Gonzalez-Gross M Gil CM Fleta J Warnberg J Ruiz JR Sarria A Marcos A Bueno M Eur J Clin Nutr 2006 60 2 191 196 10.1038/sj.ejcn.1602285 16234838 Skinfold equations for estimation of body fatness in children and youth Slaughter MH Lohman TG Boileau RA Horswill CA Stillman RJ Van Loan MD Bemben DA Hum Biol 1988 60 5 709 723 3224965 Clinical longitudinal standards for height, weight, height velocity, weight velocity, and stages of puberty Tanner JM Whitehouse RH Arch Dis Child 1976 51 3 170 179 1545912 952550 10.1136/adc.51.3.170 [Aerobic capacity of 6 to 17-year-old Quebecois – 20 meter shuttle run test with 1 minute stages] Leger L Lambert J Goulet A Rowan C Dinelle Y Can J Appl Sport Sci 1984 9 2 64 69 6733834 [Low level of physical fitness in Spanish adolescents. Relevance for future cardiovascular health (AVENA study)] Ortega FB Ruiz JR Castillo MJ Moreno LA Gonzalez-Gross M Warnberg J Gutierrez A Rev Esp Cardiol 2005 58 8 898 909 10.1157/13078126 16053823 Plasma lipid and lipoprotein levels in childhood Kwiterovich PO Jr Ann N Y Acad Sci 1991 623 90 107 10.1111/j.1749-6632.1991.tb43721.x 2042879 Serum lipids, body mass index and waist circumference during pubertal development in Spanish adolescents: the AVENA Study Ruiz JR Ortega FB Tresaco B Warnberg J Mesa JL Gonzalez-Gross M Moreno LA Marcos A Gutierrez A Castillo MJ Horm Metab Res 2006 38 12 832 837 10.1055/s-2006-956503 17163360 Simple and rapid preparation of samples for PCR Higuchi R PCR Technology Stockton Press Erlich H 1989 31 37 Restriction isotyping of human apolipoprotein E by gene amplification and cleavage with HhaI Hixson JE Vernier DT J Lipid Res 1990 31 3 545 548 2341813 Alpha-myosin heavy chain cDNA structure and gene expression in adult, fetal, and premature baboon myocardium Hixson JE Henkel RD Britten ML Vernier DT deLemos RA Berg Vande JL Walsh RA J Mol Cell Cardiol 1989 21 10 1073 1086 10.1016/0022-2828(89)90805-5 2585520 Weight regain after slimming induced by an energy-restricted diet depends on interleukin-6 and peroxisome-proliferator-activated-receptor-gamma2 gene polymorphisms Goyenechea E Dolores Parra M Alfredo Martinez J Br J Nutr 2006 96 5 965 972 10.1017/BJN20061901 17092389 Expression of peroxisome proliferator-activated receptor gamma (PPARgamma) in normal human pancreatic islet cells Dubois M Pattou F Kerr-Conte J Gmyr V Vandewalle B Desreumaux P Auwerx J Schoonjans K Lefebvre J Diabetologia 2000 43 9 1165 1169 10.1007/s001250051508 11043863 A simple sequentially rejective multiple test procedure Holm S Scand J Statist 1979 6 65 70 Simple solution to a common statistical problem: interpreting multiple tests Gordi T Khamis H Clin Ther 2004 26 5 780 786 10.1016/S0149-2918(04)90078-1 15220022 Fetal origins of adult disease-the hypothesis revisited Lucas A Fewtrell MS Cole TJ Bmj 1999 319 7204 245 249 1116334 10417093 Aerobic physical fitness in relation to blood lipids and fasting glycaemia in adolescents: Influence of weight status Mesa JL Ruiz JR Ortega FB Warnberg J Gonzalez-Lamuno D Moreno LA Gutierrez A Castillo MJ Nutr Metab Cardiovasc Dis 2006 16 4 285 293 10.1016/j.numecd.2006.02.003 16679221 Social gradients in cardiovascular risk factors and symptoms of Swedish men and women: the Goteborg MONICA Study 1995 Manhem K Dotevall A Wilhelmsen L Rosengren A J Cardiovasc Risk 2000 7 5 359 368 11143766 Sex differences in the association between birth weight and total cholesterol. A meta-analysis Lawlor DA Owen CG Davies AA Whincup PH Ebrahim S Cook DG Davey Smith G Ann Epidemiol 2006 16 1 19 25 10.1016/j.annepidem.2005.04.006 16039874 Maternal regulation of fetal development and health in adult life Godfrey KM Eur J Obstet Gynecol Reprod Biol 1998 78 2 141 150 10.1016/S0301-2115(98)00060-8 9622311 Timing is everything: a reconsideration of fetal growth velocity patterns identifies the importance of individual and sex differences Lampl M Jeanty P Am J Hum Biol 2003 15 5 667 680 10.1002/ajhb.10204 12953179 The Pro12Ala polymorphism in PPARgamma2 gene affects lipid parameters in Greek primary school children: A case of gene-to-gender interaction Dedoussis GV Theodoraki EV Manios Y Yiannakouris N Panagiotakos D Papoutsakis C Skenderi K Zampelas A Am J Med Sci 2007 333 1 10 15 10.1097/00000441-200701000-00002 17220689 Evidence for greater oxidative substrate flexibility in male carriers of the Pro 12 Ala polymorphism in PPARgamma2 Thamer C Haap M Volk A Maerker E Becker R Bachmann O Machicao F Haring HU Stumvoll M Horm Metab Res 2002 34 3 132 136 11972302 Effect of potentially modifiable risk factors associated with myocardial infarction in 52 countries (the INTERHEART study): case-control study Yusuf S Hawken S Ounpuu S Dans T Avezum A Lanas F McQueen M Budaj A Pais P Varigos J Lancet 2004 364 9438 937 952 10.1016/S0140-6736(04)17018-9 15364185 Gender related association between genetic variations of APOC-III gene and lipid and lipoprotein variables in northern France Dallongeville J Meirhaeghe A Cottel D Fruchart JC Amouyel P Helbecque N Atherosclerosis 2000 150 1 149 157 10.1016/S0021-9150(99)00362-7 10781646 Impact of APOA5/A4/C3 genetic polymorphisms on lipid variables and cardiovascular disease risk in French men Dallongeville J Cottel D Montaye M Codron V Amouyel P Helbecque N Int J Cardiol 2006 106 2 152 156 10.1016/j.ijcard.2004.10.065 16321685 Association of the Sst-I polymorphism at the APOC3 gene locus with variations in lipid levels, lipoprotein subclass profiles and coronary heart disease risk: the Framingham offspring study Russo GT Meigs JB Cupples LA Demissie S Otvos JD Wilson PW Lahoz C Cucinotta D Couture P Mallory T Atherosclerosis 2001 158 1 173 181 10.1016/S0021-9150(01)00409-9 11500189 The peroxisome proliferator-activated receptor-gamma2 Pro12Ala polymorphism Stumvoll M Haring H Diabetes 2002 51 8 2341 2347 10.2337/diabetes.51.8.2341 12145143 A Pro12Ala substitution in PPARgamma2 associated with decreased receptor activity, lower body mass index and improved insulin sensitivity Deeb SS Fajas L Nemoto M Pihlajamaki J Mykkanen L Kuusisto J Laakso M Fujimoto W Auwerx J Nat Genet 1998 20 3 284 287 10.1038/3099 9806549 Impact of the Peroxisome Proliferator Activated Receptor gamma2 Pro12Ala polymorphism on adiposity, lipids and non-insulin-dependent diabetes mellitus Meirhaeghe A Fajas L Helbecque N Cottel D Auwerx J Deeb SS Amouyel P Int J Obes Relat Metab Disord 2000 24 2 195 199 10.1038/sj.ijo.0801112 10702770 Fetal and maternal peroxisome proliferator-activated receptor gamma2 Pro12Ala does not influence birth weight Pfab T Poralla C Richter CM Godes M Slowinski T Priem F Halle H Hocher B Obesity (Silver Spring) 2006 14 11 1880 1885 10.1038/oby.2006.218 17135601

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