Table 1

Characteristics of the prospective studies (n = 11) regarding the associations between iron intake or body iron stores and the risk of type 2 diabetes mellitus (T2DM)

Author, year [reference number]

Country

Study name

Sample sizea

Age, years

Women, %

Follow-up, years

Exposure assessment

Ascertainment of T2DM


Iron intakes and T2DM (n = 5)

Jiang et al, 2004 [20]

USA

HPFS

1168/38,394

40 to 75

0

12

FFQ (validated)

Symptoms plus fasting glucose, OGTT, or use of anti-diabetic medication

Lee et al, 2004 [24]

USA

IWHS

1921/35,698

55 to 69

100

11

FFQ (validated)

Self-report

Song et al, 2004 [23]

USA

WHS

1558/37,309

≥ 45

100

8.8

FFQ (validated)

Self-report

Rajpathak et al, 2006 [21]

USA

NHS

4599/85,031

34 to 59

100

20

FFQ (validated)

Symptoms plus fasting glucose, OGTT, or use of anti-diabetic medication

Shi et al, 2010 [30]

China

JIN

23/1,056

≥ 20

57.9

5

3-day weighed food records

Fasting glucose

Body iron stores and T2DM (n = 6)

Salonen et al, 1998 [9]

Finland

KIHD

41/82

42 to 60

0

4

sTfR (EIA) ferritin (RIA)

Fasting glucose, OGTT, clinical diagnosis of diabetes or use of anti-diabetic treatment

Jiang et al, 2004 [10]

USA

NHS

698/716

56.5/56.4

100

10

sTfR (ITA); ferritin (ITA)

Symptoms plus fasting glucose, or use of anti-diabetic medication

Forouhi et al, 2007 [11]

UK

EPIC-

Norfolk

360/758

62.4/62.1

42.0

5.1

Ferritin (FIA)

Self-report, HbA1c

Jehn et al, 2007 [15]

USA

ARIC

599/690

53.5/52.8

60.4

7.9

Ferritin (ITA)

Fasting or non-fasting glucose, anti-diabetic medication use, self-report

Le et al, 2009 [16]

USA

ACLS

220/5,292

NA

32.0

4.3-4.7

Ferritin (no details of test available)

Fasting glucose, hypoglycemic medication, or ever-diagnosed T2DM

Rajpathak et al, 2009 [17]

USA

DPP

280/280

50.4/50.2

63.6

2.8

Ferritin (ITA)

OGTT, fasting glucose


Abbreviations: ACLS, Aerobics Center Longitudinal Study; ARIC, Atherosclerosis Risk in Communities; DPP, Diabetes Prevention Program; EIA, enzyme immunoassay; EPIC, European Prospective Investigation into Cancer and Nutrition; FFQ, food frequency questionnaire; FIA, fluoroimmunoassay; HbA1c, glycated hemoglobin; HPFS, Health Professionals' Follow-up Study; ITA, immunoturbidimetric assay; IWHS, Iowa Women's Health Study; JIN, Jiangsu Nutrition Study; KIHD, Kuopio Ischemic Heart Disease Risk Factor Study; NHS, Nurses' Health Study; OGTT, oral glucose tolerance test; sTfR, soluble transferrin receptor; WHS, Women's Health Study.

a Sample sizes were incident cases/participants for iron intake and T2DM, and cases/controls for body iron stores and T2DM.

Bao et al. BMC Medicine 2012 10:119   doi:10.1186/1741-7015-10-119

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