胰岛素抵抗与2型糖尿病体位性低血压的关系

目的：探讨2型糖尿病（DM）及糖尿病合并高血压（DMH）患者发生体位性低血压（PH），及其与糖尿病神经病变、高胰岛素血症和胰岛素抵抗（IR）的关系。方法：DM及DMH患者各30例。检测立卧位血压、自主及外周神经功能及血清胰岛素和血糖浓度，并计算胰岛素敏感指数。结果：单纯DM患才40%发生PH，而DMH患者发生PH者达67%，两者之间差异非常显著（P＜0.01)。DM合并PH和DMH合并PH患者的立卧位收缩压和舒张压变化幅值明显高于单纯DM患者（P＜0.01)，如DM同时合并高血压和PH者其腓总神经和腓浅神经等的传导速度明显低于单纯DM（P＜0.05)，但体位性心率变化的差值、体重指数（BMI）及空腹和餐后2h血糖浓度在3组中差别无显著性。DMH和PH者的血胰岛素浓度呈显著正相关（r=0.689,P＜0.01)。结论：DMH更易发生PH，并加重外周神经的损害。DM患者伴PH存在明显的胰岛素抵抗（IR）和高胰岛素血症，如同时合并高血压，上述代谢紊乱更明显。

Study on the relationship between insulin resistance and type 2 diabetes mellitus with postural hypotension

Objective　To investigate the occurrence of postural hypotension (PH) in patients suffering from type 2 diabetes mellitus with or without hypertension (DMH or DM), and the relationship of PH and diabetic neuropathy, hyperinsulinemia and insulin resistance. Methods　A total of 30 cases of type 2 DM and 30 cases of DMH were included in this study. The blood pressure of all subjects were measured in supine and standing body positions respectively and PH was defined as a decline from supine to standing was ≥20 mmHg in systolic blood pressures (SBP). The concentrations of blood glucose and plasma insulin were measured to calculate the insulin sensitive index (ISI). Autonomic and peripheral function was determined by measuring the postural heart rates and the conduction speeds of superficial peroneal and communicating branch of peroneal nerves etc respectively. Results　Significant difference (P<0.01) was found in the occurrence of PH in the patients with DM (40%) and those with DMH (67%). The changes of postural blood pressure were more obvious in those with DM+PH and DMH+PH than in those with simple DM (P<0.01). The conduction speeds of newes were significantly lower in those with DMH+PH than with simple DM (P<0.05), but the occurrence of autonomic neuropathy had no difference between the 2 groups. There was no difference in postural heart rate, body mass index and blood glucose levels in fasting and 2 h after meal among the DM, DM+PH and DMH+PH groups. The concentrations of plasma insulin of those with DMH+PH were significantly higher, but their ISI significantly lower than those of the patients with DM respectively (P<0.01). The decline of postural SBP in patients with DMH+PH had a significantly positive correlation with their plasma insulin levels in fasting condition (r=0.689, P<0.01). Conclusion　The patients with DMH are more prone to PH compared with those only with DM and PH damages their peripheral nerves. Most of diabetic patients with PH suffer from obvious IR and hyperinsulinemia, and if with hypertension, the above metabolic disturbances are more severe.