Obesity modulates the immune response to oxidized LDL in hypertensive patients

Abstract

Obesity and hypertension have been recognized as inflammatory diseases capable of activating the immune system, thus contributing to an increased cardiovascular risk. However, the link between adaptive immunity, obesity, and hypertension is poorly understood. We investigated the relationship of the body mass index (BMI) on the inflammatory, vascular, and immune responses in patients with hypertension na < ve of anti-hypertensive treatment. Hypertensive patients (N = 88) were divided into three groups: normal weight (NW), overweight (OW), and obese (OB) subjects. Anti-oxidized LDL autoantibodies (anti-oxLDL Abs), anti-ApoB-D peptide (anti-ApoB-D) Abs, interleukin (IL)-8 and IL-10, flow-mediated dilation (FMD) of the brachial artery, and 24-h ambulatory blood pressure monitoring (ABPM) were assessed. OB patients presented lower levels of anti-oxLDL Abs and IL-10, higher levels of IL-8, and impaired FMD, when compared to NW and OW (P < 0.05), without differences between groups regarding anti-ApoB-D Abs. After adjusting for age, systolic and diastolic blood pressure, anti-oxLDL Abs were inversely correlated with BMI and waist circumference (r = -0.24, P = 0.02 and r = -0.25, P = 0.02, respectively), whereas ApoB-D correlated with 24-h ABPM (r = 0.22, P = 0.05 for systolic, and r = 0.29, P = 0.01 for diastolic blood pressure). Regression analyses showed inverse associations of anti-oxLDL Abs with BMI (beta = -0.05, P = 0.01) and waist circumference (beta = -0.01, P = 0.02); anti-ApoB-D Abs were associated with systolic and diastolic 24-h ABPM (beta = 0.96, P = 0.04; beta = 1.02, P = 0.005, for systolic and diastolic 24-h ABPM, respectively). Among hypertensive patients, obesity modulates the immune and inflammatory milieu, determining an unfavorable balance of cytokines and reduction in titers of anti-oxLDL Abs. Twenty-four hour ABPM is associated with titers of anti-ApoB-D Abs.