RESUMEN
Obesity is a major public health problem conferring substantial excess risk for Type 2 diabetes (T2D). The role of microRNAs (miRNAs) in obesity and adipose tissue is not clearly defined. We hypothesize that circulating miRNA expression profiles vary according to differences in body mass index (BMI) and T2D and circulating miRNAs may reflect adipose tissue expression. Compared to healthy, lean individuals, circulating miR-100 was significantly lower in obese normoglycemic subjects and subjects with T2D. In visceral adipose tissue, expression of miR-100 was lower from obese subjects with T2D compared to obese subjects without T2D. miR-100 expression was significantly lower after adipogenic induction in human visceral, subcutaneous adipocytes and 3T3-L1 adipocytes. miR-100 reduced expression of mammalian target of rapamycin (mTOR) and Insulin Growth Factor Receptor (IGFR) directly. Differentiation of 3T3-L1 was accelerated by inhibition of miR-100 and reduced by miR-100 mimic transfection. Our data provide the first evidence of an association of circulating miR-100 with obesity and diabetes. Additionally, our in-vitro findings, and the miR-100 expression patterns in site-specific adipose tissue suggest miR-100 to modulate IGFR, mTOR and mediate adipogenesis.
Asunto(s)
Diabetes Mellitus Tipo 2/metabolismo , Regulación hacia Abajo , Grasa Intraabdominal/metabolismo , MicroARNs/metabolismo , Obesidad/metabolismo , Células 3T3 , Adolescente , Adulto , Anciano , Animales , Células Cultivadas , Estudios de Cohortes , Diabetes Mellitus Tipo 2/complicaciones , Femenino , Humanos , Masculino , Ratones , MicroARNs/sangre , Persona de Mediana Edad , Obesidad/complicaciones , Receptores de Somatomedina/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Adulto JovenRESUMEN
BACKGROUND: Excess adiposity is associated with cardiovascular disease (CVD) risk factors such as hypertension, diabetes mellitus and dyslipidemia. Amongst the various measures of adiposity, the best one to help predict these risk factors remains contentious. A novel index of adiposity, the Body Adiposity Index (BAI) was proposed in 2011, and has not been extensively studied in all populations. Therefore, the purpose of this study is to compare the relationship between Body Mass Index (BMI), Waist Circumference (WC), Waist-to-Hip Ratio (WHR), Waist-to-Height Ratio (WHtR), Body Adiposity Index (BAI) and CVD risk factors in the local adult population. METHODS AND FINDINGS: This is a cross sectional study involving 1,891 subjects (Chinese 59.1% Malay 22.2%, Indian 18.7%), aged 21-74 years, based on an employee health screening (2012) undertaken at a hospital in Singapore. Anthropometric indices and CVD risk factor variables were measured, and Spearman correlation, Receiver Operating Characteristic (ROC) curves and multiple logistic regressions were used. BAI consistently had the lower correlation, area under ROC and odd ratio values when compared with BMI, WC and WHtR, although differences were often small with overlapping 95% confidence intervals. After adjusting for BMI, BAI did not further increase the odds of CVD risk factors, unlike WC and WHtR (for all except hypertension and low high density lipoprotein cholesterol). When subjects with the various CVD risk factors were grouped according to established cut-offs, a BMI of ≥23.0 kg/m2 and/or WHtR ≥0.5 identified the highest proportion for all the CVD risk factors in both genders, even higher than a combination of BMI and WC. CONCLUSIONS: BAI may function as a measure of overall adiposity but it is unlikely to be better than BMI. A combination of BMI and WHtR could have the best clinical utility in identifying patients with CVD risk factors in an adult population in Singapore.
Asunto(s)
Composición Corporal , Enfermedades Cardiovasculares/epidemiología , Humanos , Factores de Riesgo , SingapurRESUMEN
OBJECTIVE: A recently developed parameter, the body adiposity index (BAI)-a composite index based on hip circumference and height-estimates the percentage (%) body adiposity indirectly. The BAI was compared with dual energy X-ray absorptiometer (DEXA)-derived % adiposity to validate the BAI in the local Chinese population. DESIGN AND METHODS: 105 Chinese were recruited and % adiposity estimated by BAI was compared with that derived from DEXA using the Bland Altman plot. A correlation study comparing the BAI with body mass index (BMI) was also done. RESULTS: BAI underestimated DEXA-derived % adiposity by a mean of 5.77% with 95% limits of agreement of ±8.4%. When stratified by gender, BMI correlated with DEXA-derived % adiposity better than BAI (r = 0.81 vs. 0.74 for males, P = 0.088, and r = 0.87 vs. 0.82 for females, P = 0.087). Hip circumference and waist circumference also correlated better with the BMI than BAI (r = 0.94 vs. 0.71 for hip circumference, P < 0.001, and r = 0.93 vs. 0.50 for waist circumference, P < 0.001, respectively). CONCLUSIONS: The BAI underestimates DEXA-derived % adiposity in a Chinese population in Singapore and is unlikely to be a better overall index of adiposity than the established BMI.