Sex differences in body fat distribution and carotid intima media thickness: cross sectional survey using data from the British regional heart study.

OBJECTIVE To determine the role of central adiposity in explaining sex differences in carotid intima media thickness (IMT). DESIGN Cross sectional survey. SETTING Two British towns. PARTICIPANTS 800 men and women aged 56-75 years. MAIN OUTCOME MEASURES Carotid IMT. RESULTS There was a continuous linear association between waist-hip ratio and IMT in both men and women. The magnitude of the association between waist to hip ratio and IMT was identical in both sexes. In age adjusted analyses IMT was 14% greater in men compared with women (age adjusted male to female ratio of geometric means 1.14; 95% confidence interval 1.07 to 1.21) with adjustment for waist to hip ratio this attenuated to no difference (1.00; 0.92 to 1.09). Adjustment for body mass index and for lifestyle risk factors had very little effect on the sex difference in mean intima media thickness. CONCLUSIONS Sex differences in body fat distribution may explain sex differences in arterial atherosclerosis.