Keywords

obstructive sleep apnea hypopnea syndrome, hypertension, circadian variation, apnea-hypopnea index (AHI), nursing

Authors

1. Wang, Yan
2. Yang, Qingchan
3. Feng, Jing
4. Cao, Jie
5. Chen, Baoyuan

ABSTRACT

Background: Obstructive sleep apnea hypopnea syndrome (OSAHS) is a common sleep-related breathing disorder. Hypertension is frequently a concomitant disorder in patients with OSAHS.

Purpose: This study investigates the prevalence and clinical features of hypertension in patients with OSAHS and explores the related nursing strategies.

Methods: Three thousand six hundred seven patients were included in this study. Subjects were divided into four groups that were categorized according to apnea-hypopnea index (AHI) scores as follows: control group (control, n = 354) with AHI < 5, mild OSAHS (mild, n = 658) with 5 <= AHI < 15, moderate OSAHS (moderate, n = 753) with 15 <= AHI < 30, and severe OSAHS (severe, n = 1842) with AHI >= 30. Blood pressure (BP) values were measured at four time points (daytime, evening, nighttime, and morning). The prevalence of hypertension and BP values in the different groups were compared at four time points. Finally, the nighttime-to-daytime mean BP (MBP; R_N/D) and morning-to-evening MBP (R_M/E) ratios were calculated.

Results: The prevalence of hypertension in the control group, mild group, moderate group, and severe group were 22.32%, 34.65%, 39.04%, and 55.37%, respectively. AHI positively correlated with the prevalence of hypertension (r = .191, p < .001). The daytime, nighttime, evening, and morning MBP rose as AHI increased. The ratios of nighttime-to-daytime MBP (R_N/D) and morning-to-evening MBP (R_M/E) increase with the severity of the illness (F = 9.821 and 18.957; p < .001). The daytime BP correlates significantly with AHI and lowest oxygen saturation (LSaO₂; systolic BP, r = .195 and -.206; diastolic BP, rs = .248 and -.251, p < .01). Daytime MBP increases gradually in small fluctuations concurrent with increases in AHI until 61-65.

Conclusions/Implications for Practice: OSAHS is an independent risk factor for hypertension. Patients with OSAHS have a significant increase in nighttime and morning BP, which means they lose normal BP diurnal rhythm. Therefore, nurses should take necessary measures based on the clinical features of hypertension in patients with OSAHS to minimize the risk of cardiocerebral vascular incidents.