A total of 103 nondippers were defined as poor or good sleepers by the Pittsburgh Sleep Quality Index. They were randomized to receive zolpidem or placebo treatment for 30 days. Stress status was assessed by the Perceived Stress Scale, and levels of epinephrine and norepinephrine were examined to investigate the underlying mechanisms.
Poor sleepers treated with zolpidem for 30 days showed significant improvements in sleep quality and stress levels (P < 0.01). More nondippers were converted to dippers in the group of poor sleepers treated with zolpidem (11 of 22 patients, 50.0 % ) than in the placebo (2 of 23, 8.7 % ) (P < 0.01). Epinephrine and norepinephrine levels were significantly reduced in poor sleepers treated with zolpidem (P < 0.05).
The results of this study suggest that zolpidem can improve sleep quality and stress status, and can convert nondippers with poor sleep quality into dippers. It may be an option for treating nondipping hypertensive patients with poor sleep quality.