Effects of Ambulatory Blood Pressure Monitoring During Polysomnography on Sleep Indices and EEG Power

Background/Objectives: Ambulatory blood pressure monitoring (ABPM) may disturb sleep during polysomnography (PSG), and the first-night effect (FNE) can complicate interpretation. We evaluated changes associated with ABPM and FNE across whole nights and individual measurements. Methods: This secondary analysis included 72 nominally healthy adults in a balanced two-night crossover, with ABPM on one randomly assigned night. Linear mixed-effects models estimated associations with PSG-derived sleep indices, a composite sleep quality index (SQI), and relative electroencephalographic (EEG) power. Analyses of individual measurements summarized EEG changes, sleep-stage transitions, and automated arousal detections. Benjamini–Hochberg false discovery rate (BH-FDR) adjustment was applied within defined analysis families. Results: FNE and ABPM were associated with lower SQI (β = −0.049 and −0.051, respectively; both BH-adjusted p = 0.028). FNE was associated with altered sleep continuity and architecture, whereas ABPM was associated with higher light-sleep and lower N3-sleep percentages and higher whole-night relative theta power. In the Night 2 paired analysis, relative delta power was lower and relative alpha, beta, and gamma power were higher during ABPM than before ABPM (all BH-adjusted p < 0.01); the theta difference did not reach significance (BH-adjusted p = 0.0632). Of 655 eligible ABPM measurements beginning during sleep, 395 (60.3%) contained at least one arousal detection within the 2 min measurement window. Conclusions: These detections indicate temporal co-occurrence and do not establish that cuff inflation caused arousal. Concurrent ABPM and study-night order should be considered when interpreting PSG. An adaptation PSG night may be considered when feasible, as may cuffless blood pressure monitoring once its accuracy has been established for the intended setting.