LIPOCALIN-2 CORRELATES WITH ARTERIAL STIFFNESS IN OBESE PATIENTS

Abstract

Objective: Increased arterial stiffness, as reflected by an increased pulse wave velocity (PWV), is independently associated with a higher risk of cardiovascular morbidity and mortality in obese patients. Obesity is a low grade chronic inflammatory process due to the increase of visceral fat and adipokine overproduction. One of these adipokines, lipocalin-2, is an important biomarker in processes dealing with inflammation and oxidative stress. The hypothesis of this study is that arterial stiffness is increased in obesity, associated with the elevation of lipocalin-2 in plasma. Design and method: The association between lipocalin-2 and PWV was analyzed in 84 subjects (74 women and 10 men) with or without obesity. Subjects were classified according to the body mass index (BMI) in normal weight (18.5 - 24.9 kg/m2, n = 43) or obesity (> 30 kg/m2, n = 41). In addition, 55 morbid obese patients (grade IV) were studied before and one year after bariatric surgery (BS). Intrinsic arterial stiffness was analyzed in omental arteries dissected from omental adipose tissue from patients undergoing BS with a pressure myograph. Results: Lipocalin-2 levels were higher in the obesity group than in the normal weight group (85.6 ng/mL vs 66.29 ng/mL, p < 0.05). Lipocalin-2 levels correlated significantly with PWV, indicative of the presence of arterial stiffness. In morbid obese patients, elevated levels of lipocalin-2 were observed prior to surgery (113.1 ± 5.0 ng/mL) and significantly decreased after surgery (94.3 ± 6.2ng/mL). Mechanical studies performed in omental arteries from these patients evidenced a stiffness index B of 13.9 ± 2.5, as an index of intrinsic arterial stiffness. Conclusions: From these results we can conclude that lipocalin-2 levels correlate with the degree of obesity and, in turn, with intrinsic arterial stiffness and pulse wave velocity.