Better association of waist circumference with insulin resistance and some cardiovascular risk factors than body mass index.

OBJECTIVE: The aim of the present study was to assess the association of the obesity, measured by body mass index (BMI) or waist circumference (WC), with both insulin resistance (IR) and some cardiovascular disease (CVD) risk factors and to reveal which of these obesity measures maintains stronger association with the IR and CVD risk factors.

METHODS: A total of 68 women in the fertile age (32 ± 6 years) were classified in three groups (normal weight, overweight, and obese) according to BMI, and in two groups (normal and high) according to WC. Systolic (SBP) and diastolic blood pressures (DBP) were measured and fasting insulin (FI), fasting glucose (FG), homeostasis model analysis insulin resistance (HOMA-IR), triglycerides (TGs), low density lipoprotein (LDL-C), and high density lipoprotein (HDL-C) were determined.

RESULTS: The values of the FI, FG, HOMA-IR, TGs, LDL-C, SBP, and DBP were significantly higher and HDL-C significantly lower in the obese subjects in comparison with the subjects with normal weight or overweight. By classifying the participants on the basis of their WC, results showed that FI, FG, HOMA-IR, TGs, LDL-C, SBP, and DBP were significantly higher, and HDL-C was significantly lower in the subjects with high WC compared with those having normal WC. Linear regression analysis was done to compare the relationships between these two obesity measures and both the IR and measured CVD risk factors. It was found that both BMI and WC significantly correlate with them, however, WC has a higher r2 (correlation coefficient) than BMI.

CONCLUSIONS: The relation between BMI and WC, as two measures of the obesity, which are simple, safe, and inexpensive to obtain as well as HOMA-IR and some CVD risk factors, was established. The original finding of this study is that WC has closer association with CVD risk factors than BMI. Thus, WC can be used to screen for the risk of some health problems as IR, and CVD risk factors in pre-menopausal females.