The effect of high evening blood pressure on obstructive sleep apnea–related morning blood pressure elevation: does sex modify this interaction effect?

• Published in: Sleep & breathing Vol. 23; no. 4; pp. 1255 - 1263
• Main Authors: Han, Su-Hyun, Kim, Hyo Jae, Lee, Sang-Ahm
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.12.2019; Springer Nature B.V
• Subjects: Adult; Aged; Apnea; Blood pressure; Blood Pressure - physiology; Circadian Rhythm - physiology; Cross-Sectional Studies; Dentistry; Female; Humans; Hypertension - physiopathology; Internal Medicine; Male; Medicine; Medicine & Public Health; Middle Aged; Neurology; Otorhinolaryngology; Pediatrics; Pneumology/Respiratory System; Retrospective Studies; Risk Factors; Sex; Sex Factors; Sleep; Sleep apnea; Sleep Apnea, Obstructive - physiopathology; Sleep Breathing Physiology and Disorders • Original Article; Sleep disorders; Hypertension; Morning blood pressure; Blood pressure; Obstructive sleep apnea; Diastolic blood pressure; Sex
• ISSN: 1520-9512; 1522-1709; 1522-1709
• DOI: 10.1007/s11325-019-01869-5

Purpose Obstructive sleep apnea (OSA) can lead to increased morning blood pressure (BP). We hypothesized that high evening BP may aggravate OSA-related morning BP elevation. Additionally, this interactional effect may be modified by sex. Methods This retrospective, cross-sectional study included newly diagnosed OSA patients with an apnea-hypopnea index (AHI) ≥ 5 per hour on a full-night polysomnography. An analysis of covariance (ANCOVA) was used to determine whether severe OSA (AHI ≥ 30) was associated with higher morning BP than mild-to-moderate OSA (5 ≤ AHI < 30) and whether there was an interaction between apnea severity and evening BP on morning BP. To identify the sex effects, analyses were performed separately in each sex group. Results A total of 1445 patients with an average age of 51.9 years (SD 11.7) (male 77.9% vs. female 22.1%; high evening BP group 22.4% vs. normal evening BP group 59.6%) were included in the study. Based on the ANCOVA, patients with severe OSA had significantly higher morning systolic BP (SBP) ( p  = 0.003), diastolic BP (DBP) ( p  < 0.001), and mean BP (MBP) ( p  < 0.001) than the mild-to-moderate group in male subjects. A significant interaction between apnea severity and evening BP was identified on morning DBP and MBP in male subjects. However, there were no differences in morning BP between severe and mild-to-moderate OSA groups in female subjects. Conclusions In male subjects, severe OSA contributed to higher morning BP than mild-to-moderate OSA. OSA-associated morning BP elevation was more prominent in the high evening BP group than in the normal BP group. Such relations were not found in female subjects.