Association between drug resistant hypertension and increased osteoprotegerin levels in hypertensive male patients with non obstructive sleep apnea

Abstract

Objectives: Increased carotid intima-media thickness (IMT) reflects subclinical vascular damage and is related to obstructive sleep apnea (OSA) syndrome and hypertension. Osteoprotegerin OPG is a member of the tumor necrosis factor superfamily and increases leukocyte adhesion. The relationship between increased OPG and atherosclerosis is Well known, but there is still no evidence whether there is an association between OPG and resistant hypertension. This study investigated the association between OPG and drug resistant hypertension in patients With OSA and non-OSA. Patients and methods: We investigated the association between serum OPG levels and carotid IMT in patients With drug resistant hypertensive OSA (ODR) patients (n= 39) and drug resistant hypertensive non-OSA(NODR) patients (n=34) and drug-responsive hypertensive non-OSA controls (n=36). Results: OPG levels and carotid IMT were found to be higher in the ODR [12.4(5.9-19.5) and 0.89 +/- 0.51 and in the NODR group [11.9(5.7-17.6) and 0.88 +/- 0.6] compared with the controls [8.4(4.8-16.5) pmollL and 0.73 +/- 0.8 um], (p= 0.01 and p=0.01 for OPG and p<0.01 and p<0.01 for carotid IMT). The carotid IMT was positively correlated with OPG levels in the ODR. group (r=0.412, p=0.016) and in the NODR group(r=0.321, p=0.024) and with apnea hypopnea index (r=0.462, p<0.001) in the ODR. There was no correlation between OPG and apnea-hypopnea index (r=0.07, p=0.564) in the ODR group. Conclusions: Increased serum OPG levels were associated with subclinical carotid atherosclerosis in patients with ODR and NODR, but not with drug-response non-OSA controls.