胰岛素与内皮细胞功能研究进展

胰岛素作为一个重要的代谢调节激素,还具有保护血管内皮细胞的作用,其作用机制可能为:调节血管内皮因子,抑制内皮细胞的收缩、增强内皮细胞间的紧密连接,防止动脉粥样硬化,调节内皮细胞的生长及活性氧簇(ROS)的表达.因此,胰岛素抵抗和高胰岛素血症导致的胰岛素信号紊乱将减弱胰岛素对内皮细胞的保护作用.然而,胰岛素是否可以成为糖尿病、肥胖等代谢性疾病慢性血管并发症的治疗药物,有待进一步研究.     

糖尿病并高血压患者高胰岛素血症初步探讨

对16例NIDDM合并高血压而无心、肾功能损害者与16例NIDDM血压正常者进行配对研究。同步检测空腹及馒头试验后血糖、胰岛素、C-肽等指标。NIDDM合并高血压组血清胰岛素水平、胰岛素/C-肽值明显高于NIDDM血压正常组,而胰岛素敏感指数则明显降低。结果表明,NIDDM合并高血压与高胰岛素血症有关,后者主要是由于肝脏对胰岛素清除率降低所致。     

A comparison between Japanese-Americans living in Hawaii and Los Angeles and native Japanese: the impact of lifestyle westernization on diabetes mellitus

We have been conducting the Hawaii-Los Angeles-Hiroshima Study since 1970, mainly to determine the effects of environmental changes on various diseases by comparing Japanese-Americans with native Japanese subjects. Japanese-Americans living in Hawaii and Los Angeles are originated mainly from Hiroshima, Japan and are genetically identical with native Japanese. Through this study, we made several clear observations about Japanese-Americans. First, Japanese-Americans were highly exposed to a westernized lifestyle ; in other words, a relatively high fat and simple carbohydrate diet with low physical activity as compared to native Japanese. Second, the prevalence of type 2 diabetes among Japanese-Americans and death from ischemic heart disease among Japanese-American diabetic patients were higher. Third, the serum fasting insulin level as well as the insulin level after a glucose load, was higher among Japanese-Americans, even when the serum glucose levels were not statistically different as compared to native Japanese. Accordingly, Japanese-Americans were thought to have a high insulin resistance status. However, the initial insulin response after a glucose load was low, which was more similar to Japanese people than to Caucasians. Fourth, the total cholesterol and triglyceride levels were higher among Japanese-Americans. These results are supposed to be derived from the insulin resistant status by the westernization of lifestyle, as well as from the weakness of pancreatic beta cell function that is supposed to be genetically regulated among Japanese. In conclusion, it appears that for genetically Japanese people, environmental factors are important for the development of metabolic diseases such as diabetes mellitus and cardiovascular disease.     

Fibroepithelial papillomatosis ("skin tags") in Rabson-Mendenhall syndrome

Rabson-Mendenhall syndrome is a rare autosomal recessive syndrome in children involving a defective insulin receptor gene. Several phenotypic features are common to this syndrome, including severe hyperinsulinemia, growth retardation, acanthosis nigricans, dental dysplasia, hirsutism, coarse facial features, and pineal hyperplasia. The authors evaluated and treated a patient with Rabson-Mendenhall syndrome who presented with additional notable syndromic sequelae including extensive fibroepithelial papillomatosis (“skin tags”), not previously described to this extent.     

正常血糖-高胰岛素血症的研究进展

高胰岛素血症是胰岛素抵抗人群为了维持血糖调节平衡的一种代偿表现,与正常血糖-非高胰岛素血症人群相比,其胰岛β细胞功能已经降低,心脑血管疾病的发病率增加,更容易发展成为2型糖尿病或葡萄糖调节受损的状态。控制体质量,适当的运动,服用双胍类及噻唑烷二酮类药物均可通过改善胰岛素敏感性来减轻胰岛β细胞的负荷,从而降低胰岛素水平。     

高胰岛素血症对冠心病患者血浆视黄醇结合蛋白4水平的影响及其临床意义

目的 观察视黄醇结合蛋白4(RBP4)在合并高胰岛素血症的冠心病患者血浆中的水平,探讨高胰岛素血症对冠心病患者RBP4的影响及其临床意义.方法 收集2009年9月～2010年5月在湘雅医院心血管内科住院并行冠状动脉造影( CAG)检查证实为冠心病患者59例,根据其胰岛素水平分为:单纯冠心病组(CHD)30例、冠心病合并高胰岛素组患者(CHD+HIn )29例;另选同期来我院行健康体检者作为正常对照组( NC )30例.酶联免疫吸附法(ELISA)检测上述人群血浆RBP4水平;测身高、体重,计算体重指数(BMI),测腰围、臀围,计算腰/臀,测收缩压与舒张压;测空腹血糖、胰岛素、餐后2h胰岛素,计算胰岛素抵抗指数(HOMA-IR),测血脂水平以及高敏C反应蛋白、尿酸、游离脂肪酸等生化指标.结果 CHD+HIn组患者血浆RBP4水平显著高于CHD组和NC组(P＜0.01),CHD与NC组间差异无统计学意义;相关分析显示RBP4与BMI、FPG、FIn、2bPIn、HOMA-IR、TG、HDL-C、UA、hsCRP有显著相关性;多元回归分析显示BMI、2hPIn、HOMA-IR是RBP4的独立相关因素.结论 合并高胰岛素血症的冠心病患者血浆RBP4水平显著升高,提示高胰岛素血症是影响RBP4的重要因素,RBP4可作为识别冠心病患者是否存在胰岛素抵抗的血清学指标;血浆RBP4与BMI、血脂、尿酸、等心血管危险因素相关,提示RBP4参与AS的发生、发展过程;BMI、2hPIn、HOMA-IR是RBP4的独立相关因素.     

二甲双胍治疗多囊卵巢综合征的疗效

目的观察二甲双胍单用及联合应用氯菧酚胺治疗多囊卵巢综合征（PCOS）患者的疗效。方法30例PCOS患者应用二甲双胍治疗3及6个周期,比较治疗前、后的体重指数、腰臀比、月经周期、排卵率、受孕率、空腹血糖、胰岛素、稳态模式评估胰岛素抵抗指数（HOMA—IR）、性激素和血脂的变化。22例加用氯菧酚胺治疗3个周期,观察月经周期、卵泡反应、排卵率及受孕率。结果二甲双胍治疗3及6个周期后,空腹胰岛素、HOMA—IR、总睾酮、游离睾酮、黄体生成素均显著下降（P值均〈0．01）;排卵率分别为43％及54％,受孕者各2例。联合治疗组排卵率为74％,4例受孕。结论二甲双胍治疗可显著改善PCOS患者的胰岛素抵抗、高雄激素血症、性激素异常及月经紊乱,改善卵泡发育,增加排卵率,提高受孕机会。     

The Role of Endocrine Insulin-Like Growth Factor-I and Insulin in Breast Cancer

Epidemiologic studies demonstrate that breast cancer is the most common type of cancer diagnosed in women and is a significant cause of morbidity and mortality. While there are many risk factors known to be associated with increased breast cancer risk, this review will focus specifically on circulating IGF-I, hyperinsulinemia, and type 2 diabetes. Their effects on promoting breast cancer development, progression, and adverse outcomes have been demonstrated in both animal and human studies, suggesting that the IGF system is a potential target for breast cancer therapy. In addition, in the clinical setting, emphasizing metabolic risk modifications to patients including weight loss, dietary changes, and diabetes control may also play an important role in breast cancer risk reduction. Dr. Derek LeRoith is presently a consultant and speaker and receives as honorarium from Merck, Sanofi-Aventis, Pfizer, Takeda, and Novo Nordisk.