Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada.
Obesity (Silver Spring). 2012 Jun;20(6):1293-300. doi: 10.1038/oby.2011.395. Epub 2012 Jan 26.
South Asians have a higher risk for cardiovascular disease (CVD) that remains largely unexplained. We hypothesized that the increased CVD risk in South Asians compared to Europeans is mediated through higher levels of visceral adipose tissue (VAT) in South Asians compared to total body fat and subcutaneous abdominal adipose tissue (SAT). South Asians (207) and Europeans (201) underwent assessment for demographics, body fat, and risk factors. Linear regression models were created by sex for each risk factor to explore mediation effects of total body fat, SAT, and VAT adjusted for age, income, smoking, and BMI (menopausal status for women). Mediation was based on changes in the ethnicity β coefficient due to additional adjustment for our adipose variable of interest and the Sobel test for mediation. South Asians had worse lipid, glucose, insulin, and C-reactive protein (CRP) levels than Europeans after adjusting for confounders. Most of these differences remained even after further adjustment by either total body fat or SAT. In contrast, VAT attenuated the ethnic differences in risk factors by 16%-52%. After adjusting for VAT, there were no longer ethnic differences in total cholesterol (TC), LDL-C, TC/HDL-C, glucose, and diastolic blood pressure (BP) in men, and in HDL-C, triglycerides (TG), TC/HDL-C, and homeostasis model (HOMA) in women, and VAT was a significant mediator for these risk factors. Higher levels of risk factors for CVD in South Asians are predominantly because of the unique phenotype of South Asians having greater VAT than Europeans even at the same BMI.
南亚人患心血管疾病（CVD）的风险较高，但这在很大程度上仍未得到解释。我们假设，与欧洲人相比，南亚人 CVD 风险增加的原因是南亚人内脏脂肪组织（VAT）水平高于全身脂肪和腹部皮下脂肪组织（SAT）。南亚人（207 人）和欧洲人（201 人）接受了人口统计学、体脂和危险因素评估。按性别为每个危险因素创建线性回归模型，以探讨全身脂肪、SAT 和 VAT 对年龄、收入、吸烟和 BMI（女性为绝经状态）调整后的中介效应。基于因额外调整我们感兴趣的脂肪变量而导致的种族β系数的变化以及中介的 Sobel 检验来进行中介。在调整混杂因素后，南亚人的血脂、血糖、胰岛素和 C 反应蛋白（CRP）水平比欧洲人差。即使进一步按全身脂肪或 SAT 调整，这些差异中的大部分仍然存在。相比之下，VAT 使危险因素的种族差异减少了 16%-52%。在调整 VAT 后，男性的总胆固醇（TC）、低密度脂蛋白胆固醇（LDL-C）、TC/高密度脂蛋白胆固醇（HDL-C）、血糖和舒张压（BP）以及女性的 HDL-C、甘油三酯（TG）、TC/HDL-C 和稳态模型（HOMA）不再存在种族差异，并且 VAT 是这些危险因素的重要中介。南亚人 CVD 危险因素较高的主要原因是南亚人独特的表型，即使在相同 BMI 下，南亚人的 VAT 也比欧洲人高。
