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

Backgrounds: 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 mu g/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. (C) 2008 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.