Differences in insulin sensitivity and risk markers due to gender and age in hypertensives

Abstract

Men run a higher risk for cardiovascular disease than women, even if hypertensive. This has been attributed to a more pronounced central (abdominal) fat distribution in men as well as menopausal state in women. The hypothesis to be tested in hypertensives was that men have more pronounced insulin resistance and other cardiovascular risk factors than pre-menopausal, but not post-menopausal, women. We carried out a cross-sectional observation study of middle-aged hypertensives of both sexes, divided into two age groups, below or over 50 years of age. The study was performed in untreated out-patients, visiting a hypertension policlinic, in Uppsala, Sweden. Three hundred men and 170 women with a mean age of 57 years were investigated. Measurements were taken by: physical examination (body mass index, waist-to-hip ratio, blood pressure); intravenous glucose tolerance test (IVGTT); euglycaemic hyperinsulinaemic clamp; and blood sampling for lipoprotein lipid fractions, uric acid, and free fatty acids. The results were that pre-menopausal women showed a higher insulin-mediated glucose disposal (7.6 vs5.8 mg/kg/min; P < 0.01), and lower fasting glucose (4.9 vs 5.2 mmol/l; P < 0.05) than men, as well as a more advantageous lipoprotein profile. however, in post menopausal women insulin sensitivity decreased and the lipoprotein profile deteriorated. women still showed higher levels of high-density lipoprotein (hdl)-cholesterol, and men a higher waist-to-hip ratio and levels of uric acid, in both age groups. it was concluded that post-menopausal hypertensive women are relatively more insulin resistant than pre-menopausal ones in comparison with men in the same age group and with the same degree of overall obesity.