Analysis of OSAS incidence and influential factors in middle-aged and elderly patients with hypertension.

BACKGROUND: To investigate the detection rate and influencing factors of obstructive sleep apnea syndrome (OSAS) in middle-aged and elderly patients with hypertension.

METHODS: A total of 440 patients with hypertension were selected as the research objects, all of them participated in the Berlin questionnaire survey, and the polysomnography (PSG) was performed on the patients with a high risk of OSAS. The detection rate of OSAS was analyzed, the clinical data between non-OSAS group and OSAS group were compared and stepwise linear regression and Logistic regression were used to analyze the related influencing factors to apnea hyponea index (AHI) and OSAS in hypertensive patients.

RESULTS: A total of 235 patients completed PSG and 196 patients were diagnosed as OSAS with the detection rate of 83.40%. The detection rate of OSAS in male patients was higher than that in females (89.04% vs.74.16%, x²=8.025, P=0.006). The detection rates of OSAS in normal BMI group, overweight group and obesity group were 56.52%, 92.37% and 100%, respectively (x²=36.438, P<0.001). The detection rates of OSAS in normal waistline group and central obesity group were 74.42% and 88.59% (x²=7.539, P=0.016). The detection rates of OSAS in grade1, grade 2 and grade 3 hypertension groups were 57.47%, 98.23% and 100%, respectively (x²=44.623, P<0.001). BMI, systolic blood pressure (SBP), diastolic blood pressure (DBP), low density lipoprotein (LDL) and waist circumference of OSAS group were all higher than those in non-OSAS group (P<0.05). BMI, SBP and DBP were positively correlated with AHI (p<0.05), which were independent risk factors of OSAS [OR value (95%CI) = 2.548 (1.449-4.327), 1.342 (1.214-1.965) and 1.169 (1.025-1.622), respectively, P<0.05].

CONCLUSIONS: The incidence of OSAS in middle-aged and elderly patients with hypertension is high. High BMI, SBP, and DBP are independent risk factors of OSAS.