Correlative factors of insulin resistance in essential hypertension

Essential Hypertension (EH) is correlated with a metabolic disturbance char acterized by insulin resistance (IR). In this study, there were observed in 47 subjects with EH and 30 subjects with normal blood pressure. Serum leve ls of insulin-like growth factor-1 (IGF-1), serum levels of growth hormone (GH), the activity of erythrocyte insulin receptors (EIR), and ATP levels i n erythrocytes, the insulin sensitivity index (ISI) was used to study the c orrelative factors of essential hypertension. 1. Among patients with EH, IS I, GH, and low affinity insulin binding sites of EIRs (RT2) were found to b e in significantly lower amounts, IGF-1 levels and the KDP of the erythrocy te insulin receptors were noted to be significantly higher. Compared with t he control group, there was a marked difference between EH group and the co ntrol group. However, no statistical difference was observed between the hy pertensive group and the group with normal blood pressure as regards erythr ocyte ATP levels, high-affinity insulin binding sites of EIRs (RT1), and th e KD1 of EIRs. 2. In the hypertensive group, the ISI was negatively correla ted with mean arterial blood pressure (MBP), a family history of hypertensi on, the body mass index (BMI), the waist-hip ratio (WHR) and IGF-1 levels ( r=-0.619(Delta), -0.354**, -0.386**, -0.472**, -0.298*, Delta p<0.001, **p< 0.01, *p<0.05), were positively correlated with RT2 and GH levels (r= 0.301 **, 0.275*, **p<0.01, *p<0.05). There were no statistically significant di fferences between ISI and age, sex, smoking history, drinking, RT1, KD1, an d ATP levels in erythrocytes. 3. The ISI was used as the dependent variable in multiple linear stepwise regression analysis. MBP (X-1), a family histo ry of EH (X-2), WHR (X-3), GH (X-4), IGF-1 (X-5), RT2 (X-6), and the body m ass index (X-7) was used as independent variables. X-1, X-2, X-3, X-5, X-6, and X-7 were used in the equations. The results indicate that patients wit h EH also tend to have IR. We suggest that MBP, a family history of hyperte nsion, BMI, WHR, IGF-1, and RT2 might be independent factors affecting IR i n cases of essential hypertension.