Diabetes and Obesity in Mexican Pima Indians

1995年，NIDDK的凤凰城流行病学和临床研究分会进行了一项横断面研究，以确定传统和西方环境对墨西哥和美国皮马印第安人2型糖尿病和肥胖症流行的影响。墨西哥皮马人生活在Maycoba村的一个偏远山区，1995年他们的传统生活方式几乎没有变化。同样数量的非皮马墨西哥人生活在梅科巴。与墨西哥皮马不同，美国皮马生活在一个更加西化的社会，他们有很高的糖尿病患病率。调查发现，尽管糖尿病和肥胖症在墨西哥PIMA比非PIMA更普遍，但这两个墨西哥群体的这些疾病的患病率都明显低于美国PIMA。 本项目是与来自北亚利桑那大学和墨西哥Hermosillo的食品和食品调查中心的调查人员合作进行的。在Maycoba的皮马居民和非皮马居民中进行了另一项调查，采用了1995年调查中使用的相同方法，以确定自第一次调查以来2型糖尿病、肥胖症和相关情况的流行程度发生了多大的变化。主要调查试图招收尽可能多的梅科巴居民。在人群的一个子集(100个个体)中，休息和总能量消耗分别通过使用通风罩和双标记水的间接量热法测量。根据这些测量结果，将计算出体力活动能量消耗。还在另一组个人中进行了一项人种学调查，以收集有关健康信念、社区环境变化和口腔健康做法的信息。 马科巴的调查现已完成。在主要调查中，共有657名梅科巴居民参加；其中369人至少有部分皮马血统。这占梅科巴合格皮马人口的84%，占合格非皮马人口的81%。糖尿病患病率在非PIMA男性、非PIMA和PIMA女性中都有所增加，但在PIMA男性中没有增加。肥胖率在所有人群中都有所上升，肥胖症与个人能够接触到的现代技术特征的数量密切相关，这表明它受到“现代化”的影响。对饮食、体力活动和遗传多态的其他分析目前正在进行中。对80个已确定的糖尿病或肥胖变量的分析表明，大多数已确定的2型糖尿病变量在墨西哥皮马和亚利桑那州皮马之间的患病率没有差异；亚利桑那州已建立的肥胖变量的频率往往高于墨西哥皮马，这可能解释了肥胖风险差异的一小部分。在与1型糖尿病和其他免疫疾病有关的人类白细胞抗原中，观察到频率上的显著差异；目前正在分析对人类白细胞抗原a基因座的更多研究，对其他遗传数据的研究目前正在进行中，对DNA甲基化的研究也在进行中，DNA甲基化是一种反映遗传和环境影响的表观遗传标记。

In 1995 the Phoenix Epidemiology and Clinical Research Branch of NIDDK conducted a cross-sectional study to identify the effects of traditional and western environments on prevalence of type 2 diabetes mellitus and obesity in Pima Indians in Mexico and the United States. The Mexican Pimas live in a remote mountainous region in the village of Maycoba and in 1995 had experienced little change from their traditional lifestyle. A similar number of non-Pima Mexicans live in Maycoba. In contrast to the Mexican Pimas, the U.S. Pimas live in a more westernized society and they have a high prevalence of diabetes. The survey found that although diabetes and obesity were more prevalent in Mexican Pimas than non-Pimas, both Mexican groups had a significantly lower prevalence of these disorders than U.S. Pimas. The present project is being conducted in collaboration with investigators from Northern Arizona University and Centro de Investigacion en Alimentacion y Desarollo in Hermosillo, Mexico. Another survey was undertaken among the Pima and non-Pima residents of Maycoba, using the same methods used in the 1995 survey, to determine the extent to which the prevalence of T2DM, obesity and related conditions changed since the original survey. The main survey attempted to enroll as many of the residents of Maycoba as possible. In a subset of the population (100 individuals), resting and total energy expenditure were measured by indirect calorimetry using a ventilated hood and by doubly-labeled water, respectively. From these measurements, physical activity energy expenditure will be calculated. An ethnographic survey has also been conducted in a different subset of individuals to collect information about health beliefs, environmental changes in the community and oral health practices. The surveys in Maycoba have now been completed. In the main survey a total of 657 residents of Maycoba have participated; 369 of the individuals are of at least partial Pima heritage. This constitutes 84% of the eligible Pima population of Maycoba, and 81% of the eligible non-Pima population. The prevalence of diabetes increased in non-Pima men and in both non-Pima and Pima women, but not in Pima men. Prevalence of obesity increased in all groups, and obesity was strongly associated with the number of modern technological features to which an individual had access, suggesting it is influenced by "modernization". Additional analyses of diet, physical activity and of genetic polymorphisms are currently underway. Analyses of 80 established diabetes or obesity variants suggest that most established type 2 diabetes variants do not differ in prevalence between Mexican Pimas and Arizona Pimas; the frequency of established obesity variants tends to be higher in Arizona than in Mexican Pimas, and this may account for a modest proportion of the difference in obesity risk. A marked difference in frequency is observed at HLA, which is involved in type 1 diabetes and other immune diseases; additional studies of the HLA locus a currently being analyzed and studies of other genetic data are currently underway, as are studies of DNA methylation, an epigenetic marker that reflects genetic and environmental influences.