Age-standardized diabetes risk factors in case and control subjects in U.S. women
| Case subjects | Control subjects | P | |
|---|---|---|---|
| n | 714 | 1120 | |
| Age (years) | 54.4 | 54.5 | 0.83 |
| BMI (kg/m2) | 30.4 | 27.2 | <0.001 |
| Physical activity (metabolic equivalent task hours/week) | 12.2 | 14.9 | <0.001 |
| Alcohol consumption (g/day) | 2.9 | 5.2 | <0.001 |
| Ethnicity (% white) | 95.1 | 95.6 | 0.60 |
| Current smoker (%) | 14.5 | 12.0 | 0.11 |
| Postmenopausal status (%) | 75.6 | 75.3 | 0.52 |
| Family history of diabetes (%) | 46.8 | 22.3 | <0.001 |
| Biomarkers | |||
| Insulin (μU/ml)* | 13.8 | 10.5 | <0.001 |
| Proinsulin (fmol/ml) | 26.0 | 11.7 | <0.001 |
| CRP (mg/dl) | 0.52 | 0.23 | <0.001 |
| Ferritin (ng/ml) | 69.4 | 46.5 | <0.001 |
| Ratio of transferrin receptor to ferritin | 46.1 | 64.1 | <0.001 |
| Dietary intakes | |||
| Total iron (mg/day) | 17.3 | 17.4 | 0.90 |
| Nonsupplemental iron (mg/day) | 12.3 | 12.5 | 0.39 |
| Supplemental iron (mg/day) | 4.9 | 4.9 | 0.90 |
| Heme iron (mg/day) | 1.12 | 1.06 | 0.001 |
| Red meat (servings/day × 1,000 kcal) | 1.21 | 1.12 | 0.002 |
* Insulin and proinsulin were measured in fasting samples only (insulin in 415 case subjects and 570 control subjects and proinsulin in 200 case subjects and 306 control subjects).