LIPOPROTEIN COMPOSITION AND METABOLISM IN PIMA INDIANS

皮马印第安人肥胖、糖尿病等疾病的患病率很高 高胰岛素血症，但血浆胆固醇水平低，降低低 密度脂蛋白（LDL）和高密度脂蛋白（HDL）降低 心血管疾病（CVD）的发病率。 脂蛋白的组成和 为了进一步研究皮马印第安人的新陈代谢 了解脂蛋白代谢的控制以及脂蛋白是如何运作的 与肥胖和CVD有关。 已开发出多室模型 用于分析同时测量 VLDL、IDL 的动力学数据， 和 LDL apoB 代谢。 Pimas 和 Pima 中 apoB 代谢的比较 体重匹配的白种人表明，皮马人的低 LDL 与 LDL 的 FCR 更高，VLDL 代谢比例更高 转化为低密度脂蛋白。 脂蛋白代谢研究的结果表明 底物和调节剂（例如胰岛素）的大量通量导致 脂蛋白的过度产生，但补偿机制是 操作导致维持低血浆浓度。 为了了解 HDL 缺乏性别差异的原因 皮马斯人，我们研究了 HDL 组成、脂肪酶活性和类固醇 激素浓度。 数据表明，该人群肥胖 对HDL的浓度和组成有更大的影响 妇女。 肥胖女性 HDL 的变化与 血浆雌二醇水平和肝脂肪酶活性增加。 由于皮马族人口中的瘦女性很少，最终结果是 整个人口中女性的 HDL 水平与 那些男人的。

Pima Indians have a high prevalence of obesity, diabetes mellitus, and hyperinsulinemia, but they have low plasma cholesterol levels, reduced low density lipoprotein (LDL) and high density lipoprotein (HDL), and decreased incidence of cardiovascular disease (CVD). Lipoprotein composition and metabolism in Pima Indians are being investigated in order to further understand control of lipoprotein metabolism and how lipoproteins are related to obesity and CVD. A multicompartmental model has been developed for the analysis of kinetic data for the simultaneous measure of VLDL, IDL, and LDL apoB metabolism. Comparsion of apoB metabolism in Pimas and weight-matched Caucasians indicated that the low LDL in Pimas is related to both higher FCR for LDL and higher proportion of VLDL metabolized without conversion to LDL. The results of lipoprotein metabolism studies suggest a large flux of substrates and regulators (e.g., insulin) which cause overproduction of lipoproteins, but that compensatory mechanisms are operative which result in maintenance of low plasma concentrations. In order to understand the reason for the lack of sex differences in HDL in the Pimas, we have studied HDL composition, lipase activities, and steroid hormone concentrations. The data indicated that obesity in this population has a stronger influence on both concentrations and composition of HDL in women. The change in HDL in obese women was associated with decreases in levels of plasma estradiol and increases in hepatic lipase activities. Since there are so few lean women in the Pima population, the net result is that HDL levels in women in the population as a whole do not differ from those of men.