The effect of abdominal obesity on insulin sensitivity and serum lipid and cytokine concentrations in African women.

Abstract

Objectives Studies have shown clear associations of abdominal obesity with lipid and glucose metabolism and cytokine levels in a number of different population groups. However, no such studies have been performed in an African population in which visceral adipose tissue levels have been shown to be lower than in European subjects.

Design and patients Cross-sectional analysis in 124 African women.

Measurements Fasting serum samples were taken from all subjects and anthropometric measurements obtained. Blood levels of glucose, insulin, total cholesterol, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol, triglyceride, interleukin (IL)-6, IL-8 and IL-18 were measured. Subjects were separated into normal and abnormal glucose tolerant groups and into tertiles according to waist circumference (WC). Insulin resistance was assessed using the homeostasis model assessment (HOMA).

Results Abnormal glucose-tolerant subjects had higher WC, glucose and HOMA levels than the normal glucose-tolerant group. Increased WC was associated with higher triglyceride, insulin and HOMA levels and lower HDL levels. Multiple regression analyses showed that WC associated positively with HOMA and serum triglyceride levels and negatively with HDL levels. IL18 was a positive but weak determinant of the HOMA level and BMI correlated positively with serum IL-6 concentrations.

Conclusions Although previous studies have shown that African subjects have a lower visceral adipose depot size than European subjects, abdominal obesity is still associated with insulin resistance and dyslipidaemia. The association between abdominal obesity and metabolic dysfunction within this population is not dependent upon IL-6, IL-8 or IL-18.