Dietarary fibers and glycemic load, obesity, and plasma adiponectin levels in women with type 2 diabetes

OBJECTIVE - The purpose of this study was to examine the associations of dietary fibers and glycemic load with plasma adiponectin in diabetic women and investigate the modification effect of obesity. RESEARCH DESIGN AND METHODS - We conducted a cross-sectional analysis in 902 women with type 2 diabetes from the Nurses' Health Study. Dietary information was obtained using semiquantitative food frequency questionnaires. RESULTS - After adjustment for age, smoking, alcohol consumption, physical activity, aspirin use, HbA(1c) history of hypertension and hypercholesterolemia, and postmenopausal hormone use, intakes of cereal fiber and fruit fiber (P for trend = 0.002 and 0.036, respectively) were Significantly associated with an increasing trend of plasma adiponectin concentrations. Further adjustment for BMI did not appreciably change the associations for cereal fiber but attenuated the associations for fruit fiber. Adiponectin concentrations were 24% higher in the highest compared with the lowest quintile of cereal fiber. Dietary glycemic load and glycemic index were significantly associated with lower plasma adiponectin levels, after adjustment for BMI and other covariates (P for trend = 0.01 and 0.03, respectively). The percent differences in adiponectin concentration between the highest and the lowest quintiles of dietary glycemic load and glycemic index were 17 and 18%, respectively. The associations between dietary factors and plasma adiponectin were consistent across lean (BMI < 25 kg/m(2)), overweight (25 <= BMI < 30 kg/m(2)), and obese subjects (BMI >= 30 kg/m(2)). CONCLUSIONS - Our data indicate that dietary cereal fiber and glycemic load/index are associated with the circulating adiponectin concentration. Such associations were not modified by obesity status.