Abstract Introduction This was a pilot study designed to test the hypothesis that bedtime administration of acetylsalicylic acid (ASA) lowers BP through sleep improvements that impact the inflammatory, and renin-angiotensin-aldosterone system (RAAS). We predicted that ASA would enhance sleep consolidation and lower sympathetic activation, protecting against the physiological stress of fragmented sleep. Materials and methods Seven participants (5F, 2 M, mean age 25.71 ± 4.03 years, BMI 22.40 ± 1.91 kg/m2) completed this within-subject, double-blind, balanced study involving 2x5 in-patient days. Participants were randomized to daily intake of ASA (81 mg/day) or placebo at bedtime for 2 weeks before each hospital research stay that included 1 baseline (BL) night, 2 nights of an experimental sleep disturbance (ESD) protocol and finally, 1 night of recovery sleep. The ESD protocol included 1-hour delayed sleep onset, fragmentation of sleep with 5x20-minute awakenings, and a 1-hour earlier lights on time. Results ASA did not decrease BP following the 2-week at-home ASA administration, nor during ESD. Evening renin was significantly reduced (p = .048), compared to placebo after 2 weeks of ASA. Mood and well-being improved after 2 weeks of ASA. There were statistical trends towards decreased 24-hr average heart rate (p = .053), and increased heart rate variability (HRV) (p = .080). When challenged with the ESD protocol, ASA was associated with a longer duration of individual slow waves (p = .013), lower 24-hr average HR (p .001) and a trend to greater NREM delta power (p = .061). Conclusions This pilot study is the first investigation exploring effects of ASA on renal & hemodynamic parameters at night, implicating sleep as an important mechanistic factor.
Vazquez et al. (Thu,) studied this question.