慢性盐负荷对血压正常盐敏感性个体胰岛素抗性的影响

Effects of Chronic Dietary Salt loading on Insulin Resistance in Salt Sensitive Normotensive Individuals

目的观察慢性盐负荷对血压正常盐敏感者个体胰岛素抗性的影响。方法对２３例血压正常的健康志愿者，通过３天的平衡饮食期（ＮａＣｌ１４ｇ／ｄ），７天的高盐饮食期（ＮａＣｌ２３ｇ／ｄ）及７天的低盐饮食期（ＮａＣｌ３ｇ／ｄ）在确定盐敏感性的同时，进行口服葡萄糖耐量试验及胰岛素释放试验。结果盐敏感者慢性高盐负荷使空腹血胰岛素水平及胰岛素释放量明显增加，与盐不敏感者差异显著，空腹血胰岛素为１２．２±５．７对７．４±１．７μＵ／ｍｌ，胰岛素曲线下面积分别为７４．６±２１．９对３９．０±１２．４μＵ·ｈ－１·Ｌ－１，Ｐ均＜０．０５；敏感者高盐负荷后与平衡饮食期相比，葡萄糖负荷试验后的１ｈ及曲线下面积亦有升高倾向。结论高盐摄入在升高盐敏感者血压的同时。

Aim\ To observe the effects of chronic salt loading on insulin resistance in salt sensitive individuals with normotension.\ Methods\ Twenty three cases of normotensive volunteers underwent a dietary salt protocol consisting of 3 days of balanced sodium diet(NaCl, 14 g/d), 7 days of high sodium diet(NaCl, 23 g/d) and 7 days of low sodium diet(NaCl, 3 g/d) to determine salt sensitives(SS),14 subjects were defined as nonsalt sensitive while 9 were salt sensitive. Oral glucose tolerance test(OGTT) and insulin release test(IRT) were performed before and after the high sodium diet period.\ Results\ In SS,with chronic salt loading, the fasting plasma insulin level was much higher and the insulin responses to OGTT increased than those in the NSS, the fasting insulin was 122±57 vs 74±17 μU/ml(P<005) and the area under curves of insulin after IRT was 746±219 vs 390±124 μU·h -1 ·L -1 , P<005, respectively. After salt loading, the glucose levels in 60 minutes OGTT and the area under curves of glucose in SS were higher than those in the balanced salt diet.\ Conclusion\ High salt loading increasing blood pressure in salt sensitive individuals with normotension.