Sex differences in cardiovascular risk factors independent of abdominal fat distribution

Abstract

To investigate sex differences in cardiovascular risk factors within a healthy middle-aged population. Cross-sectional, observational study. Primary health care in Dalby, Sweden. 19 males and 19 postmenopausal females, selected for normotension, and matched for age (58 years) and body mass index (26 kg/m2). At two visits, with a five year interval, subjects were investigated according to height, weight, and blood pressure (ambulant and in the doctor's surgery). The fat-free mass was calculated using the von Döbeln formula. Glucose metabolism was evaluated with an oral glucose tolerance test (glucose, insulin, C-peptide). Lipid levels, liver enzymes, and hormonal variables (cortisol, sex hormones) were also measured. Males showed higher levels than females of glucose, insulin, triglycerides, and liver enzymes at the first visit, even after elimination of the influence of differences in weight. At the follow-up visit, males also had a higher 24-hour diastolic blood pressure than females (79.4 vs. 71.8 mm Hg; p < 0.01), as well as higher triglyceride levels (1.45 vs. 0.95 mmol/l; p < 0.05), even after elimination of the influence of abdominal fat distribution. No differences in smoking or daily intake of nutrients (per 1000 kcal) were seen, but alcohol intake differed in absolute terms (males 8.5 vs. females 2.3 g/d; p < 0.05). Healthy middle-aged males differ in an unfavourable way from matched postmenopausal females in several cardiovascular risk factors. This is not fully explained by differences in abdominal fat distribution and sex hormone levels, nor by the influence of food intake and smoking habits.