Gruska S, Wolf E, Jendral I, Wedler B, Kraatz G
Department for Internal Medicine, Ernst-Moritz-Arndt University Greifswald, Germany.
Exp Clin Endocrinol Diabetes. 1997;105 Suppl 2:22-6. doi: 10.1055/s-0029-1211790.
Among hypertensive patients salt sensitivity and insulin resistance are commonly observed together. We investigated if a causal relationship already exists in young normotensive adults. With a standardized dietary regimen we determined salt sensitivity in 35 male volunteers by measuring diastolic blood pressure (24-hours-RR-recording). Insulin resistance was tested using hyperinsulinaemic-euglycaemic-clamp-technique by de Fronzo after a freely chosen diet, after 7 days of salt loading (260 mmol/d) and after 7 days of salt restriction (60 mmol/d). Data from euglycaemic-clamp technique were available from 27 subjects. 18 of them (67%) could be characterized as salt resistant; 9 persons (33%) were salt sensitive. Glucose infusion rate, mean glucose and insulin concentrations were measured in plasma, metabolic clearance rate (MCR) and indices of insulin sensitivity (ISI) were calculated. The results of MCR and ISI show large interindividual variances. There were no differences between the salt sensitive and salt resistant group regarding the mean insulin concentrations and also the mean glucose uptake in the steady state clamp period and also the calculated MCR and ISI. Comparing the periods of different salt intake, there were no differences between salt loading and salt restriction. Whereas salt sensitivity can already be shown in the normotensive state, with this experimental design a changed insulin sensitivity is not detectable. This supports the idea, that insulin resistance is not causally linked with salt sensitivity. It may be a secondary phenomenon of salt induced hypertension.
在高血压患者中，盐敏感性和胰岛素抵抗常常同时出现。我们研究了在年轻的血压正常成年人中是否已经存在因果关系。通过标准化饮食方案，我们通过测量舒张压（24小时RR记录）来确定35名男性志愿者的盐敏感性。在自由选择饮食后、盐负荷（260 mmol/d）7天后和盐限制（60 mmol/d）7天后，使用德·弗隆佐的高胰岛素正常血糖钳夹技术测试胰岛素抵抗。27名受试者可获得来自正常血糖钳夹技术的数据。其中18人（67%）可被归类为盐抵抗型；9人（33%）为盐敏感型。测量血浆中的葡萄糖输注速率、平均葡萄糖和胰岛素浓度，计算代谢清除率（MCR）和胰岛素敏感性指数（ISI）。MCR和ISI的结果显示个体间差异很大。在盐敏感组和盐抵抗组之间，平均胰岛素浓度、稳态钳夹期的平均葡萄糖摄取以及计算出的MCR和ISI均无差异。比较不同盐摄入量的时期，盐负荷和盐限制之间没有差异。虽然在血压正常状态下就可以显示盐敏感性，但通过这种实验设计无法检测到胰岛素敏感性的变化。这支持了胰岛素抵抗与盐敏感性没有因果联系的观点。它可能是盐诱导高血压的一种继发现象。
