Table 2

Determinants of participation for those eligible for the trial
All eligible people Participants Nonparticipants Significance*
n= 956^ n= 536 n= 420
Median age in years 44 (36–51) 45 (37–52) 44 (35–51) 0.13
Men (%) 468 (49.0) 265 (49.4) 203 (48.3) 0.73
 18–34 years (%) 212 (22.2) 109 (20.3) 103 (24.5)
 35–44 years (%) 280 (29.3) 159 (29.7) 121 (28.8)
 45–60 years (%) 464 (48.5) 268 (50.0) 196 (46.7)
Education (%) 0.02**
 Elementarya 126 (13.6) 61 (11.7) 65 (16.1)
 Intermediateb 645 (69.8) 364 (70.0) 281 (69.6)
 University or equivalentc 153 (16.6) 95 (18.3) 58 (14.4)
Relatives with DM (%)d 685 (73.7) 398 (76.2) 287 (70.3) 0.04**
Median weight in kg 73.5 (64.8–82.0) 73.3 (65.0–82.1) 73.8 (64.0–82.1) 0.90
 Median BMI in kg/m2 26.8 (24.4–29.9) 26.8 (24.5–29.7) 26.7 (24.1–30.3) 0.98
 Overweight: ≥ 23 kg/m2 (%)e 419 (44.9) 246 (46.9) 173 (42.3) 0.17
Obesity: ≥ 27.5 kg/m2 (%)e 412 (44.1) 227 (43.2) 185 (45.2) 0.54
Median SBP in mm Hg 128.0 (119.0–38.0) 127.0 (118.0–137.0) 129.0 (120.0–0.0) 0.07
Median DBP in mm Hg 83.0 (76.0–90.0) 82.0 (76.0–90.0) 84.0 (76.0–92.0) 0.06
 Hypertension (%)f| 62 (38.4) 196 (37.1) 166 (40.1) 0.34
Median FPG (mmol/l) 5.3 (4.9–5.7) 5.3 (4.9–5.7) 5.4 (5.0–5.7) 0.61
 Elevated FPG(%) 332 (34.8) 174 (32.5) 158 (37.9) 0.08
Median HbA1c in percentage 5.7 (5.4–6.0) 5.7 (5.4–6.0) 5.7 (5.4–5.9) 0.36
 Elevated HbA1c: ≥ 6.0% (%) 238 (25.1) 138 (25.8) 100 (24.2) 0.57
Median HOMA in mmol/mol 3.2 (2.6–4.4) 3.2 (2.5–4.3) 3.3 (2.7–4.4) 0.36
 HOMA-IR: ≥ 2.39 (%) 800 (84.0) 453 (84.5) 347 (83.4) 0.65

Determinants measured during initial screening only; only determinants measured in total population are shown Data are n (percentages, calculated excluding missings), means (SD) if normally distributed or medians (IQRs) if not normally distributed ^All people labeled as ‘at high risk of diabetes’ (n = 1045) minus people who were found not eligible for the trial (n = 67 prior to randomization and n = 22 because of suspected DM during baseline measurement) *p calculated with chi-squared test (binary data), independent t-test (continuous data), and Mann–Whitney U test (ordinal/nominal data and not normal distributed data).

**p < 0.05 – chi-squared test (Relatives with DM)/Mann–Whitney U test (Education).

aPrimary education or less.

bLow vocational training, lower secondary education, intermediate vocational training and higher secondary education.

cHigher vocational training or university.

dFirst and second grade.

eBMI of 23–27.5 kg/m2 was considered overweight; a BMI of 27.5 kg/m2 or more, obesity [48].

fSBP ≥140 mm Hg and/or of DBP ≥ 90 mm Hg or if hypertension medication.

gAmerican Diabetes Association definition: fasting glucose value of 100–125 mg/dl (5.6–6.9 mmol/l).

BMI, body mass index; DBP, diastolic blood pressure; DM, type 2 diabetes mellitus; FPG, fasting plasma glucose; HbA1c, glycated hemoglobin; HOMA-IR, homeostasis model assessment of estimated insulin resistance; IQR, interquartile range; SBP, systolic blood pressure.

Vlaar et al.

Vlaar et al. BMC Public Health 2012 12:371   doi:10.1186/1471-2458-12-371

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