Study on the relationship between blood pressure and plasma neuropeptide Y among patients with obstructive sleep apnea-hypopnea syndrome

Abstract

Objective To investigate the role of plasma neuropeptide Y (NPY) in physiopathologic process of obstructive sleep apnea-hypopnea syndrome (OSAHS) accompanied by hypertension. Methods Thirty-one patients with OSAHS were placed into the OSAHS group,and 30 normal subjects into the control group. First, the plasma concentrations of NPY, right upper extremity arteria brachialis blood pressure,apnea-hypopnea index ( AHI) , minimal saturation of pulse oxygen ( MinSpO2 ) and time when percent of nocturnal oxygen saturation lower than 90% (T-SaO2＜90%) were measured respectively. And the relationship between NPY and the other variables were analyzed in both groups. Second,26 OSAHS patients accepted nasal continuous positive airway pressure (nCPAP) therapy. After 3-month treatment with nCPAP,plasma concentration of NPY,right upper extremity arteria brachialis blood pressure, AHI,MinSpO2 and T-SaO2＜90% were remeasured and compared with the OSAHS group. Results Our study indicated that compared to the control subjects the patients with OSAHS had higher mean arterial pressure (MAP) and the NPY level in plasma ( P ＜0. 01). After the 3-month nCPAP therapy both MAP and the NPY level were significantly decreased(P ＜0. 01). And the decrease of MAP and the plasma level of NPY had positive correlation with AHI ( P ＜0. 01). The decrease of MAP also had positive correlation with the decrease of the plasma level of NPY ( P ＜0. 05). In all groups. MAP and the plasma level of NPY both had positive correlation with AHI, T-SaO2 ＜ 90% (P ＜ 0. 01), and negative correlation with MinSpO2 ( P ＜0. 01). MAP exhibited positive correlation with the plasma level of NPY in all groups (P＜0. 01). Stepwise multiple regression analysis showed that regression equation was: NPY= 2. 229 X AHI-2. 928 X MinSpO2 + 1. 729 X MAP+ 279. 321. Conclusions Our research suggests that there is a close relationship between the plasma NPY level and the OSAHS combined with hypertension. nCPAP therapy could not only decrease the MAP but also the plasma NPY level in OSAHS patients. Correct treatment was effective not only on OSAHS but also on coexisting hypertension. Key words: Obstructive sleep apnea-hypopnea syndrome; Neuropeptide Y; Hypertension