Jacob S, Rett K, Wicklmayr M, Agrawal B, Augustin H J, Dietze G J
Department of Internal Medicine, Stadtklinik, Baden-Baden, Germany.
J Hypertens. 1996 Apr;14(4):489-94.
Hypertensive patients frequently show resistance to insulin-stimulated glucose uptake and hyperinsulinemia. Diuretics and beta-adrenoceptor blocking agents have been found to decrease insulin sensitivity, whereas alpha 1-blockers and angiotensin converting enzyme inhibitors seem to improve it.
To compare the effects of a 3 months' antihypertensive treatment with carvedilol, a non-selective beta-adrenoceptor blocker with alpha 1-blocking properties, with the beta 1-selective receptor blocker metoprolol on insulin sensitivity in non-diabetic hypertensive patients.
A multicenter double-blind randomized study.
Seventy-two non-diabetic hypertensive patients were randomly assigned to treatment with either carvedilol or metoprolol. An isoglycemic, hyperinsulinemic glucose clamp was conducted before and after 12 weeks of treatment; the metabolic clearance rate for glucose was taken as an indicator of insulin sensitivity.
The two groups did not differ in age, sex, body mass index, blood pressure or lipids, and treatment effectively lowered blood pressure. In both groups, insulin sensitivity was impaired at baseline. After metoprolol treatment, insulin sensitivity further decreased significantly by about 14%, whereas it increased after carvedilol. There was also a decrease in high-density lipoprotein and an increase in triglycerides levels in patients in the metoprolol-treated group, whereas these parameters remained unchanged in patients in the carvedilol-treated group.
This study confirms previous findings of a reduction in insulin sensitivity after chronic metoprolol treatment. Carvedilol treatment, however, resulted in a small amelioration of insulin resistance and a better lipid profile [corrected]. We thus demonstrate that a beta-blocker with alpha 1-blocking properties has favorable effects on glucose metabolism, suggesting a potentially important role of peripheral blood flow in regulating glucose uptake. These findings imply that beta-blocker treatment, when combined with alpha 1-blocking activity has advantageous effects on insulin sensitivity and lipids and could therefore be suitable for patients with the metabolic syndrome.
高血压患者常表现出对胰岛素刺激的葡萄糖摄取抵抗及高胰岛素血症。已发现利尿剂和β肾上腺素受体阻滞剂会降低胰岛素敏感性，而α1受体阻滞剂和血管紧张素转换酶抑制剂似乎可改善胰岛素敏感性。
比较非选择性β肾上腺素受体阻滞剂兼α1受体阻断特性的卡维地洛与β1选择性受体阻滞剂美托洛尔对非糖尿病高血压患者进行3个月降压治疗后胰岛素敏感性的影响。
一项多中心双盲随机研究。
72例非糖尿病高血压患者被随机分配接受卡维地洛或美托洛尔治疗。在治疗12周前后进行等血糖、高胰岛素葡萄糖钳夹试验；葡萄糖代谢清除率作为胰岛素敏感性指标。
两组在年龄、性别、体重指数、血压或血脂方面无差异，且治疗均有效降低了血压。两组在基线时胰岛素敏感性均受损。美托洛尔治疗后，胰岛素敏感性进一步显著降低约14%，而卡维地洛治疗后胰岛素敏感性增加。美托洛尔治疗组患者的高密度脂蛋白降低，甘油三酯水平升高，而卡维地洛治疗组患者这些参数保持不变。
本研究证实了先前关于长期美托洛尔治疗后胰岛素敏感性降低的研究结果。然而，卡维地洛治疗可使胰岛素抵抗略有改善，并改善血脂状况[校正后]。因此，我们证明具有α1受体阻断特性的β受体阻滞剂对葡萄糖代谢有有利影响，提示外周血流在调节葡萄糖摄取中可能起重要作用。这些发现表明，兼具α1受体阻断活性的β受体阻滞剂治疗对胰岛素敏感性和血脂有有利影响，因此可能适用于代谢综合征患者。
