Denver Health Medical Center, 660 Bannock Street, Denver, CO 80204, USA.
BMC Endocr Disord. 2011 Jul 7;11:13. doi: 10.1186/1472-6823-11-13.
Latinos in the United States have a higher prevalence of type 2 diabetes than non-Latino whites, even after controlling for adiposity. Decreased adiponectin is associated with insulin resistance and predicts T2DM, and therefore may mediate this ethnic difference. We compared total and high-molecular-weight (HMW) adiponectin in Latino versus white individuals, identified factors associated with adiponectin in each ethnic group, and measured the contribution of adiponectin to ethnic differences in insulin resistance.
We utilized cross-sectional data from subjects in the Latinos Using Cardio Health Actions to reduce Risk study. Participants were Latino (n = 119) and non-Latino white (n = 60) men and women with hypertension and at least one other risk factor for CVD (age 61 ± 10 yrs, 49% with T2DM), seen at an integrated community health and hospital system in Denver, Colorado. Total and HMW adiponectin was measured by RIA and ELISA respectively. Fasting glucose and insulin were used to calculate the homeostasis model insulin resistance index (HOMA-IR). Variables independently associated with adiponectin levels were identified by linear regression analyses. Adiponectin's contribution to ethnic differences in insulin resistance was assessed in multivariate linear regression models of Latino ethnicity, with logHOMA-IR as a dependent variable, adjusting for possible confounders including age, gender, adiposity, and renal function.
Mean adiponectin levels were lower in Latino than white patients (beta estimates: -4.5 (-6.4, -2.5), p < 0.001 and -1.6 (-2.7, -0.5), p < 0.005 for total and HMW adiponectin), independent of age, gender, BMI/waist circumference, thiazolidinedione use, diabetes status, and renal function. An expected negative association between adiponectin and waist circumference was seen among women and non-Latino white men, but no relationship between these two variables was observed among Latino men. Ethnic differences in logHOMA-IR were no longer observed after controlling for adiponectin levels.
Among patients with CVD risk, total and HMW adiponectin is lower in Latinos, independent of adiposity and other known regulators of adiponectin. Ethnic differences in adiponectin regulation may exist and future research in this area is warranted. Adiponectin levels accounted for the observed variability in insulin resistance, suggesting a contribution of decreased adiponectin to insulin resistance in Latino populations.
在美国，拉丁裔人群患 2 型糖尿病的比例高于非拉丁裔白种人，即使在控制肥胖程度后也是如此。脂联素的减少与胰岛素抵抗有关，并可预测 2 型糖尿病，因此可能介导这种种族差异。我们比较了拉丁裔和白种个体中的总脂联素和高分子量（HMW）脂联素，确定了每个种族中与脂联素相关的因素，并测量了脂联素对胰岛素抵抗的种族差异的贡献。
我们利用了来自拉丁裔使用心脏健康行动来降低风险研究中的参与者的横断面数据。参与者为拉丁裔（n=119）和非拉丁裔白种人（n=60）男性和女性，患有高血压和至少一种其他心血管疾病（CVD）危险因素（年龄 61±10 岁，49%患有 2 型糖尿病），在科罗拉多州丹佛市的一个综合社区卫生和医院系统中接受治疗。总脂联素和 HMW 脂联素分别通过 RIA 和 ELISA 测量。空腹血糖和胰岛素用于计算稳态模型胰岛素抵抗指数（HOMA-IR）。通过线性回归分析确定与脂联素水平独立相关的变量。在多元线性回归模型中，以 logHOMA-IR 为因变量，调整可能的混杂因素，包括年龄、性别、肥胖程度和肾功能，评估脂联素对拉丁裔和白种人之间胰岛素抵抗差异的贡献。
与白种人患者相比，拉丁裔患者的脂联素水平更低（β估计值：-4.5（-6.4，-2.5），p<0.001 和-1.6（-2.7，-0.5），p<0.005 用于总脂联素和 HMW 脂联素），独立于年龄、性别、BMI/腰围、噻唑烷二酮使用、糖尿病状态和肾功能。在女性和非拉丁裔白种男性中观察到脂联素与腰围之间的预期负相关，但在拉丁裔男性中未观察到这两个变量之间的关系。在控制脂联素水平后，观察到的 logHOMA-IR 种族差异不再存在。
在患有 CVD 风险的患者中，总脂联素和 HMW 脂联素在拉丁裔人群中较低，独立于肥胖程度和其他已知的脂联素调节剂。脂联素调节的种族差异可能存在，需要在这一领域进行进一步研究。脂联素水平解释了胰岛素抵抗的可变性，表明在拉丁裔人群中，脂联素的减少可能导致胰岛素抵抗。
