Not all obese subjects of multiethnic origin are at similar risk for developing hypertension and type 2 diabetes
Received 26 April 2008; received in revised form 26 August 2008; accepted 22 September 2008. published online 29 October 2008.
Abstract
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/m2) 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 µg/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.
aHypertension Clinic, Laboratory of Clinical and Experimental Pathophysiology, (CLINEX), School of Medicine, Rio de Janeiro State University, Brazil
bHuman Genetics Laboratory, Oswaldo Cruz Institute, Ministry of Health, Brazil
Corresponding author. Laboratory of Clinical and Experimental Pathophysiology — CLINEX, Rua Paulo Cesar de Andrade 106 ap. 602 — Laranjeiras, Rio de Janeiro — CEP 22221-090, Brazil. Tel.: +55 21 2587 6836; fax: +55 21 2587 6836.
ABSTRACT