Nocturnal Blood Pressure Patterns in Hypertensive patients with Obstructive Sleep Apnea Syndrome in Angola

Abstract

The main cardiovascular consequence of Obstructive Sleep Apnea Syndrome (OSAS) is arterial hypertension (AH), considered since 2003 a second cause of AH. This study aimed to evaluate nocturnal blood pressure patterns (BPP) in hypertensive patients with OSAS in Angola. A descriptive, cross-sectional observational study was carried out in a private clinic in Angola. Demographic and clinical variables, polysomnography, and ABPM parameters were included. Patients were classified as a dippers, non-dippers, and reverse dippers. One-way ANOVA test, Kruskal-Walli’s test, and chi-square test were used as appropriate. The sample consisted of 70 individuals: 39(55.7%) were male. The mean age was 53.63±9.14 years and the BMI was 35.82 ± 6.57 kg/m2. An association between patients with a past medical history of hypertension and BPP was found (p<0.05). Mean O2 saturation was significantly lower in the reverse dippers (p=0.25). Although insignificantly, the dippers were younger and less obese. In contrast, the proportion of smokers and diabetics was higher in the reverse dippers. No correlation was found between the apnea-hypopnea index, the mean blood pressure, and the Epworth sleepiness scale. In the present study, the prevalence of non-dipping and reverse dipping patterns was high. It needs to be confirmed with future prospective studies.