TABLE 1

Age-standardized diabetes risk factors in case and control subjects in U.S. women

Case subjectsControl subjectsP
n7141120
Age (years)54.454.50.83
BMI (kg/m2)30.427.2<0.001
Physical activity (metabolic equivalent task hours/week)12.214.9<0.001
Alcohol consumption (g/day)2.95.2<0.001
Ethnicity (% white)95.195.60.60
Current smoker (%)14.512.00.11
Postmenopausal status (%)75.675.30.52
Family history of diabetes (%)46.822.3<0.001
Biomarkers
    Insulin (μU/ml)*13.810.5<0.001
    Proinsulin (fmol/ml)26.011.7<0.001
    CRP (mg/dl)0.520.23<0.001
    Ferritin (ng/ml)69.446.5<0.001
Ratio of transferrin receptor to ferritin46.164.1<0.001
Dietary intakes
    Total iron (mg/day)17.317.40.90
    Nonsupplemental iron (mg/day)12.312.50.39
    Supplemental iron (mg/day)4.94.90.90
    Heme iron (mg/day)1.121.060.001
    Red meat (servings/day × 1,000 kcal)1.211.120.002
  • *

    * 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).