High Incidence of Masked Hypertension in Patients with Obstructive Sleep Apnoea Despite Normal Automated Office Blood Pressure Measurement Results

Abstract

Introduction: Obstructive sleep apnoea (OSA) is a well-known risk factor for masked hypertension (MH) and masked uncontrolled hypertension (MUCH). Automated ambulatory office blood pressure measurement (AOBP) might better correlate with the results of ambulatory blood pressure measurements (ABPM) compared to routine office blood pressure measurement (OBPM). The aim of this study was to compare the diagnostic rate of MH/MUCH when using OBPM and AOBP in combination with ABPM. Material and methods: 65 OSA patients, of which 58 were males, (AHI > 5, mean 44.4; range 5-103) of average age 48.8 ± 10.7 years were involved in this study. Following MH/MUCH criteria were used; Criteria I: OBPM < 140/90 mm Hg and daytime ABPM > 135/85 mm Hg; Criteria II: AOBP < 140/90 mm Hg and daytime ABPM > 135/85 mm Hg; Criteria III: AOBP < 135/85 mm Hg and daytime ABPM > 135/85 mm Hg. Results: MH/MUCH criteria I was met in 16 patients (24.6%) with criteria II being met in 37 patients (56.9%), and criteria III in 33 (51.0%), p < 0.0001. Both systolic and diastolic OBPM were significantly higher than AOBP; Systolic (mm Hg): 135.3 ± 12.3 vs 122.1 ± 10.1 (p < 0.0001); Diastolic (mm Hg): 87.4 ± 8.9 vs 77.1 ± 9.3 (p < 0.0001). AOBP was significantly lower than daytime ABPM; Systolic (mm Hg): 122.1 ± 10.1 vs 138.9 ± 10.5 (p < 0.0001); Diastolic (mm Hg): 77.1 ± 9.3 vs 81.6 ± 8.1 (p < 0.0001). Non-dipping phenomenon was present in 38 patients (58.4%). Nocturnal hypertension was present in 55 patients (84.6%). Conclusions: In patients with OSA there is a much higher prevalence of MH/MUCH despite normal AOBP, therefore it is necessary to perform a 24-hour ABPM even if OBPM and AOBP are normal.

Assessment of hypertension in obstructive sleep apnea by ambulatory blood pressure monitoring: a systematic review and meta-analysis

“…With the exception of the studies by Baguet et al 14-17, all the other included cohorts analyzed also patients with known hypertension. However, with the exception of Sova et al [19], in all the studies that included hypertensive patients, the antihypertensive treatment was discontinued at least 3 weeks before the examination [18,20,21], making an interaction between the antihypertensive treatment and the results from our analysis unlikely. Similarly, with the exception of the papers by Wilcox et al [20,21], which included only men, the rest of the studies included both sexes.…”

“…However, with the exception of Sova et al . [19], in all the studies that included hypertensive patients, the antihypertensive treatment was discontinued at least 3 weeks before the examination [18,20,21], making an interaction between the antihypertensive treatment and the results from our analysis unlikely. Similarly, with the exception of the papers by Wilcox et al .…”

“…Masked and white-coat hypertension were assessed in two [14,15] and four [14,15,18,19] studies, respectively. The resulting cumulative prevalence was 34% (95% CI, 27–40%, I 2 = 59%; P = 0.12) and 9% (95 CI, 2–16%; I 2 = 89%; P < 0.01) for masked and white-coat hypertension, respectively (Figs.…”

“…Prevalence of hypertension according to daytime and nighttime ambulatory BP was variable, spanning from 51% [16] to 61% [21] and 68% [16] to 85% [19], respectively. A cumulative analysis of five studies (493 patients) [15,16,18,19,21], based on office BP showed a cumulative prevalence of hypertension of 44% (95% CI, 37-52%; I 2 = 64%; P = 0.02) (Fig. 2).…”

“…3, Supplementary Digital Content 5, http://links.lww.com/BPMJ/A170). Excluding the study performed by Sova et al [19], the only one with nighttime assessment included in the analysis reduced the cumulative prevalence of hypertension to 59% (95% CI, 50-68%) and also the heterogeneity (I 2 = 67%; P = 0.05).…”