Not all obese subjects of multiethnic origin are at similar risk for developing hypertension and type 2 diabetes.

Abstract

BACKGROUND: Whether insulin resistance and not obesity per se is the major contributor to clinical outcomes associated with obesity has not been fully established. This study evaluated in a group of obese Brazilians of multiethnic origin to what extent the prevalence of hypertension and other cardiometabolic risk factors varies as a function of the degree of insulin sensitivity. METHODS: The study involved 118 individuals (mean age of 44+/-12 years; BMI=38.6+/-7.9 kg/m(2)) without evidence of diabetes or cardiovascular disease. Insulin resistance was assessed by HOMA-IR index, which was used to stratify patients into tertiles. RESULTS: The mean HOMA-IR in tertile 1, the most insulin-sensitive group, was 2.7+/-0.8 and in tertile 3, the most insulin-resistant group, 9.1+/-2.4 (P<0.001). Mean arterial pressure showed a linear and significant variation across the HOMA-IR tertiles 1, 2, and 3 (94.3+/-11.7; 98.7+/-11.4; 105.0+/-12.4 mm Hg), as did fasting plasma glucose (93.6+/-12.1; 98.1+/-12.7; 100.0+/-11.0 mg/dL), uric acid (4.7+/-1.4; 5.9+/-1.9; 6.3+/-1.4 mg/dL), HDL-cholesterol (48.1+/-11.6; 46.5+/-10.5; 42.2+/-8.0 mg/dL), and plasma adiponectin (7.8+/-3.3; 7.0+/-2.8; 6.3+/-6.5 microg/mL), respectively. The results indicated that 27.5% of our patients had dysglicemia, 28.2% had hypertriglyceridemia, and 30.7% had arterial hypertension in the most insulin-sensitive tertile, when compared with 51%, 53.8% and 79.4%, respectively, in the most insulin-resistant tertile. A stepwise regression analysis showed that only HOMA-IR and age independently affected the risk for increased systolic blood pressure. CONCLUSION: In conclusion, our findings have shown that the risk of developing essential hypertension, type 2 diabetes, and cardiovascular disease is accentuated in obese individuals who are also more insulin resistant.