Determinants of postprandial lipemia in obese women

Abstract

OBJECTIVE:To quantify the effects of fasting lipids, age, apolipoprotein (apo) E polymorphism, insulin resistance, body fat and abdominal fat distribution, on postprandial lipemia (PPL) in non-diabetic obese women.

DESIGN:Cross-sectional, prospective.

SUBJECTS:A total of 93 obese women (mean±s.d. age 39±13 y; body mass index (BMI) 38.3±4.9 kg\m²) and 16 nonobese women (25±8 y; BMI 22.7±3.2 kg\m²).

MEASUREMENTS:Body fat distribution was determined by the ratio of waist-to-hip circumferences (WHR) and by computed tomography (CT) at the L4-L5 level. Apo E genotyping was performed by restriction isotyping. Insulin resistance was calculated from fasting glucose and insulin concentrations. PPL was evaluated using the vitamin A-fat tolerance test (1.0 g fat\kg body weight and 7.0 mg cholesterol\kg body weight+300 000 IU vitamin A palmitate). Blood samples were drawn before, and every 1.5 h for 7.5 h plus 24 h after ingestion of the fat meal. Areas under the response curves (AUC) for triglycerides (TG) and retinyl palmitate (RP) were calculated using the geometrical method for two time intervals, that is, 0–7.5 h and 0–24 h.

RESULTS:Incremental AUCs TG, but not AUCs RP, were increased in the obese women. Apo E polymorphism, BMI, WHR and menopausal state did not influence PPL in the obese women. Fasting TG, age, the intra-abdominal to subcutaneous abdominal fat ratio (IA\SC ratio) and insulin resistance were independent determinants of PPL. Together, fasting TG, IA\SC ratio and insulin resistance, explained 38% of the variance in AUC TG 0–7.5 h (P=0.0001).

CONCLUSION:Alterations in PPL are to be added to the increasing number of components of the plurimetabolic syndrome.