NIGHTLY MELATONIN SUPPLEMENTATION IMPROVES TOTAL SLEEP TIME, SLEEP EFFICIENCY AND SLEEP ONSET LATENCY IN HYPERTENSIVE PATIENTS TREATED WITH â-BLOCKERS

Scheer FA1,2, Morris CJ1,2, Marks J1, Smales C1, Kelly EE1, Garcia JI1, Hahn M1, Xiong M1, Malhotra A1,2, Shea SA1,2

1Medical Chronobiology Program, Division of Sleep Medicine, Brigham and Women’s Hospital, Boston, MA, USA, 2Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA

Introduction:

â-Blockers are often used in the treatment of hypertension, angina, arrhythmia, and heart failure. However, â-blockers also lower the levels of the soporific hormone melatonin, which may explain some of the reported side-effects including night-time insomnia and daytime fatigue. Therefore, we tested whether or not nightly melatonin supplementation improves sleep in hypertensive patients treated with â-blockers.

Methods:

Sixteen hypertensive patients (45-64 years of age; 9 women) treated with the â-blocker Atenolol or Metoprolol were enrolled in a randomized, double-blind, placebo-controlled, parallel-group trial. The study included two 4-day in-laboratory visits during which their sleep was assessed by polysomnography in a private, sound-attenuated, and completely dark room during 8-h sleep opportunities. After the baseline assessment during the first visit, patients were randomized to receive melatonin 2.5 mg or placebo nightly for 3-4 weeks, after which their sleep was assessed again during the second 4-day visit. One subject was excluded from analysis due to unstable medication dose. Baseline-adjusted values are reported.

Results:

3-4 Weeks of melatonin supplementation increased total sleep time (placebo: 387 min vs. melatonin: 424 min; P=0.046), increased sleep efficiency (81% vs. 88%; P=0.046), and decreased sleep onset latency (16 min vs. 5 min; latency to Stage 1; P=0.007) as assessed by polysomnography in the laboratory. Melatonin did not significantly affect durations of different sleep stages, although the increase in Stage 2 approached significance (232 min vs. 271 min; P=0.051). Also through- out the 3-4 weeks while on melatonin and sleeping at home, melatonin significantly improved actigraphy-estimated total sleep time (377 min vs. 390 min; P=0.011) and sleep efficiency (78% vs. 81%; P=0.007), but not sleep onset latency.

Conclusion:

In hypertensive patients treated with â-blockers, night-time melatonin supplementation significantly improves sleep quality as assessed by polysomnography in the laboratory and as estimated by actigraphy at home.