Caffeinated Coffee, Decaffeinated Coffee, and Caffeine in Relation to Plasma C-Peptide Levels, a Marker of Insulin Secretion, in U.S. Women

• DOI: 10.2337/diacare.28.6.1390
• Publication Date: 2007-03-05T22:51:27Z
• Authors: Tianying Wu; Walter C. Willett; Susan E. Hankinson; Edward Giovannucci
• Keywords: C-peptide

OBJECTIVE—Coffee consumption is associated with reduced risk of type 2 diabetes, but the mechanism not clearly understood. Elevated C-peptide, as a marker insulin secretion, has been linked to insulin-resistant diabetes. In this study, we examined caffeinated and decaffeinated coffee total caffeine in relation concentrations plasma C-peptide. RESEARCH DESIGN AND METHODS—Plasma C-peptide were measured cross-sectional setting among 2,112 healthy women from Nurses’ Health Study I who provided blood samples 1989–1990. Consumption was assessed using semiquantitative food-frequency questionnaire 1990. RESULTS—Intakes 1990 each inversely concentration age-adjusted, BMI-adjusted, multivariable-adjusted analyses. multivariable analysis, 16% less drank >4 cups/day or compared nondrinkers (P < 0.005 for each). Women highest quintile lowest intake had 10% lower levels = 0.02). We did find any association between tea The inverse considerably stronger obese (27% reduction) overweight (20% than normal weight (11% 0.005). CONCLUSIONS—Our findings suggest potential reduction secretion by women. This may be related other components rather caffeine.