Adipocyte Hypertrophy, Fatty Liver and Metabolic Risk Factors in South Asians: The Molecular Study of Health and Risk in Ethnic Groups (mol-SHARE)

Abstract

ObjectiveWe sought to determine if differences in the distribution and characteristics of adipose tissue between South Asians and white Caucasians account for differences in risk factors for cardiovascular disease.Research Design and MethodsWe recruited 108 healthy South Asians (36.8 years) and white Caucasians (34.2 years) within three BMI strata. Body composition, adipocyte size, abdominal fat area, and hepatic adiposity were assessed and related to fasting glucose, insulin, lipids and adiponectin.ResultsAfter adjustment for age, sex, and BMI, South Asians compared to white Caucasians had higher ln fasting insulin (mean difference (md): 0.44; 95% CI: 0.20–0.69), lower HDL cholesterol (md: −0.13; 95% CI:−0.26 to −0.01), and lower adiponectin (md: −2.38; 95% CI: −3.59 to −1.17). South Asians also had more body fat (md: 2.69; 95% CI: 0.70 to 4.69), lower lean muscle mass (md: −3.25; 95%CI: −5.35 to −1.14), increased waist to hip ratio (md: 0.03; 95% CI: 0.01–0.05), less superficial subcutaneous abdominal adipose tissue (md: −2.94; 95% CI: −5.56 to−0.32), more deep/visceral to superficial adipose tissue ratio (md 0.34; 95% CI: 0.02 to 0.65), and more liver fat (md: 7.43%; 95% CI: 2.30 to 12.55%). Adipocyte area was increased in South Asians compared to white Caucasians (md: 64.26; 95% CI: 24.3 to 104.1) units2. Adjustment for adipocyte area attenuated the ethnic differences in insulin (md: 0.22; 95% CI: −0.07 to 0.51), HDL (md: −0.01; 95% CI: −0.16 to 0.13) and adiponectin (md: −1.11; 95% CI: −2.61 to 0.39). Adjustment for differences in adipocyte area and fat distribution attenuated the ethnic difference in liver fat (md: 5.19; 95% CI: 0.31 to 10.06).ConclusionSouth Asians have an increased adipocyte area compared to white Caucasians. This difference accounts for the ethnic differences in insulin, HDL cholesterol, adiponectin, and ectopic fat deposition in the liver.

Ethnic differences in BMI, subcutaneous fat, and serum leptin levels during and after pregnancy and risk of gestational diabetes

“…However, our findings are in accordance with a study that found no differences in deep or superficial subcutaneous fat between Norwegian and Pakistani women with type 2 diabetes (35). On the other hand, South Asians have been found to have larger adipocyte size (36), which, in turn, has been associated with insulin resistance and hyperleptinemia (37) and type 2 diabetes independently of insulin resistance (38). Therefore, the relative amount of subcutaneous fat may be the same, while the number of adipocytes may be lower and the adipocytes larger in South Asians vs Europeans.…”

Ethnic differences in primary care management of diabetes and cardiovascular disease in people with serious mental illness

“…However, smoking and obesity rates remain high and should be the target of public health programmes. [16][17][18] For south Asian patients, the cut-off for being obese was set at a BMI of over 25 kg/m 2 . For patients who were not south Asian, the cut-off was set at a BMI of >30 kg/m 2 .…”

Prevalence and Risk Factors of Elevated Blood Pressure, Overweight, and Dyslipidemia in Adolescent and Young Adults in Rural Nepal

“…6,8 Also, South Asians living in Canada had greater fasting insulin, lower high-density lipoprotein cholesterol (HDL-C), lower adiponectin, greater body fat, lower lean body mass, and more hepatic fat compared to Caucasians, after adjusting for age, sex, and body mass index (BMI). 9 Our research group has also found that disease risk is apparent in rural Nepali women, even at normal BMI and waist circumference (WC) levels. 10 The World Health Organization (WHO) Global Status Report focused on eight risk factors for NCDs: (1) Tobacco use, (2) harmful use of alcohol, (3) unhealthy diet, (4) raised blood pressure, (5) overweight and obesity, (6) raised cholesterol, (7) inadequate physical activity, and (8) cancerassociated infections.…”