Effects of diet-induced weight loss on the cardiometabolic markers in obese African American and white women with prediabetes

Abstract

Objective: The objective was to investigate the effects of a 6 month diet-induced weight loss (DIWL) on glucose homeostasis, cardiometabolic variables, and high density lipoproteins (HDL) associated functionality paraoxonase1 (PON1) enzyme in overweight/obese African American (AA) and White American (WA) women, with prediabetes. Methods: We recruited 108 obese women (67 AA and 41 WA) with prediabetes hemoglobin A 1 C (HbA 1 C; 5.7-6.4%). Metabolic studies, fasting cardiometabolic markers (lipids/lipoproteins, inflammatory markers), and PON1 were performed at 0, 3, and 6 months. Insulin sensitivity (Si), glucose effectiveness (Sg), acute insulin response to glucose (AIRg), and disposition index (DI) were obtained (Bergman's Minmod). The DIWL program consists of approximately 1200 kcal/day for 6 months. Results: The mean body mass index was greater in AA than WA (38 ± 8 vs. 34 ± 8 kg/m 2 ). DIWL resulted in a mean 7.5% and 10.3% (8kg vs. 10.3 kg) weight loss in AA versus WA. Mean fasting and 2 h serum glucose, insulin, and c-peptide levels decreased significantly during 3 and 6 versus 0 month. The mean Si, Sg, AIRg, and DI did not improve in either AA or WA. DIWL had no significant effect on the cardiometabolic markers or PON1 in the present study. Conclusions: We found ethnic differences in the magnitude of the weight loss. However, modest weight loss had no impact on the glucose homeostasis, cardiovascular markers, and HDL functionality in prediabetic AA and WA women.