Serum adiponectin and expression of adiponectin receptor 1 in the arterial muscular tissue in young and middle-aged hypertensive patients

Abstract

Objective. To evaluate the serum adipokines and the degree of expression of adiponectin type 1 receptors (AdipoR1) in the brachial arteries with small and medium diameter of the muscular tissue in young and middleaged patients with hypertension (HTN).Design and methods. We included 50 patients with HTN 1–3 degree (18 to 60 years old), 30 underwent surgery due to trauma-related fractures on the shoulder. The control group included 20 otherwise healthy non-smoking volunteers, 10 underwent surgery due to trauma-related fractures of the shoulder. The serum levels of adiponectin and leptin were determined by the method of enzyme immunoassay. The biopsy of the muscle tissue were analyzed by the immunohistochemistry using primary polyclonal rabbit antibodies against AdipoR1 (Santa Cruze, sc‑99183, USA, 1:500). The data were processed using software Statistica 6.0. The Mann–Whitney criterion U, and Spearman’s correlation analysis were applied. Differences were considered statistically significant at p < 0,05.Results. Young and middle-aged patients with HTN had higher body massindex (BMI), waist circumference (WC), cholesterol, low-density lipoprotein cholesterol than control group. The serum adiponectin level was 5.48 (4,11; 6,95) μg/ml in HTN patients (p > 0,05), the leptin — 3,0 (2,2; 3,5) μg/ml (p > 0,05). Women with HTN showed higher leptin level — 3,4 (2,7; 3,6) μg/ml (р < 0,05). Women had a positive relationship between leptin and BMI (r = 0,6; p = 0,001), WC (r = 0,5; p = 0,02). The control group demonstrated normal vascular wall structure. Patients with HTN had two types of muscle vessel remodeling. The elastofibrosis was found in small vessels, circular hypertrophy was found in medium diameter vessels. Expression of AdipoR1 was the highest in the area of hypertrophy, reaching 14,1% (12,22; 16,83). Expression of AdipoR1 in the muscular wall of the vessels of the control group was the lowest and constituted 1,09% (0,37; 1,41). The increase in AdipoR1 correlated with the glucose level (r = 0,5; p = 0,02) in women with HTN and AdipoR1/high density lipoprotein (HDL) (r = –0,6; p = 0,04) in men and women with HTN.Conclusions. Women with HTN had increased serum leptin. Leptin directly correlated with BMI and WC. HTN patients demonstrate two types of vascular remodeling: arteriolosclerosis in small vessels and hypertrophic circular remodeling in vessels of medium diameter. There were 14% AdipoR1 labels in hypertrophic area. No significant relationship between serum adiponectin and AdipoR1 were found in the patient groups. Glucose level positively correlated with AdipoR1 in the arteries of medium diameter in hypertensive women, while serum HDL level negatively correlated with AdipoR1 in all patient groups.