Evaluation of endothelial function and arterial stiffness in obese individuals with insulin resistance.

Abstract

Obesity is associated with metabolic imbalance, including insulin resistance and endothelial dysfunction. We aimed to evaluate clinical and vascular parameters in obese with or without insulin resistance. Participants ( n=39) were divided into two groups according to Homeostasis Model Assessment - Insulin Resistance lower (group 1) or higher (group 2) than 2.7. All patients were submitted to clinical, anthropometric, biochemical, vascular structure and endothelial function assessment. The mean age (53±9 vs. 52±7 years, p=0.784) and body mass index (34.3±4.1 vs. 35.2±3.9 kg/m2, p=0.464) were similar in both groups, and 74.4% were treated hypertensive subjects. Fasting glucose (84±7 vs. 97±18 mg/dl, p=0.004) and insulin (9.32±2.48 vs. 22.74±7.49 μU/ml, p<0.001) were higher in group 2. Group 2 presented lower HDL-cholesterol (59±14 vs. 42±12 mg/dl, p<0.001) and higher triglycerides (122±87 vs. 191±112 mg/dl, p=0.042) levels compared with group 1. HOMA-IR was correlated with abdominal circumference ( r=0.51, p=0.001), abdominal/hip ratio ( r=0.57, p<0.001) and triglycerides/HDL ratio ( r=0.53, p=0.001). Differences in brachial flow-mediated dilation did not reach statistical significance (10.2±6.2 vs. 7.9±4.7%, p=0.245). Carotid intima-media thickness, carotid-femoral pulse wave velocity (8.5±1.9 vs. 9.1±1.5 m/s, p=0.334) and central hemodynamic parameters were also similar between groups. Obese individuals with insulin resistance have higher visceral adiposity associated with impaired glucose and lipid metabolism. Endothelial function and arterial stiffness were similar between the groups, perhaps because of antihypertensive treatment in most of these subjects.