Zan-feng Wang1, Xue-wei Feng, Jian Kang. 1. Institute of Respiratory Diseases, First Hospital, China Medical University, Shenyang 110001, China.
Abstract
OBJECTIVE: To evaluate the endothelial function in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) by measuring the brachial artery diameter during reactive hyperemia. METHODS: Thirty patients with OSAHS (8 with mild and 22 with moderate/severe OSAHS) and 10 control subjects were studied. Brachial artery diameter was measured with Doppler ultrasound under baseline conditions, during reactive hyperemia (an endothelium-dependent dilatation) and after sublingual administration of nitroglycerin (an endothelium-independent vasodilator). The dilative rate of brachial artery in different conditions was calculated to evaluate the endothelial function. RESULTS: The dilative rate of brachial artery in the control group, the mild OSAHS group and the moderate/severe OSAHS group were (15.2 +/- 2.6)%, (14.3 +/- 3.2)% and (9.8 +/- 4.9)%, respectively. There was a significant decrease of endothelium-dependent flow-mediated dilation in the moderate/severe OSAHS group compared to the control group and the mild OSAHS group. No significant difference in endothelium-independent vasodilator after sublingual administration of nitroglycerin was found among the three groups. CONCLUSION: Patients with moderate/severe OSAHS have impaired endothelium-dependent vasodilatation, and OSAHS itself maybe a risk factor for endothelial dysfunction.
OBJECTIVE: To evaluate the endothelial function in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) by measuring the brachial artery diameter during reactive hyperemia. METHODS: Thirty patients with OSAHS (8 with mild and 22 with moderate/severe OSAHS) and 10 control subjects were studied. Brachial artery diameter was measured with Doppler ultrasound under baseline conditions, during reactive hyperemia (an endothelium-dependent dilatation) and after sublingual administration of nitroglycerin (an endothelium-independent vasodilator). The dilative rate of brachial artery in different conditions was calculated to evaluate the endothelial function. RESULTS: The dilative rate of brachial artery in the control group, the mild OSAHS group and the moderate/severe OSAHS group were (15.2 +/- 2.6)%, (14.3 +/- 3.2)% and (9.8 +/- 4.9)%, respectively. There was a significant decrease of endothelium-dependent flow-mediated dilation in the moderate/severe OSAHS group compared to the control group and the mild OSAHS group. No significant difference in endothelium-independent vasodilator after sublingual administration of nitroglycerin was found among the three groups. CONCLUSION:Patients with moderate/severe OSAHS have impaired endothelium-dependent vasodilatation, and OSAHS itself maybe a risk factor for endothelial dysfunction.