Effects of Melatonin on Salivary Levels of Cortisol and Sleep Quality of Hemodialysis Patients: A Randomized Clinical Trial

Objective: The aim of this study was to investigate the effects of exogenous melatonin on the quality of sleep in patients undergoing dialysis and to investigate its mechanism for the regulation of total circadian rhythm and salivary levels of cortisol in hemodialysis patients admitted to Pange Azar hospital in Gorgan in winter of 2017. Method: This was a double-blind randomized clinical trial. Samples were transferred to the laboratory by maintaining the cold chain. Then, the patients were divided into two groups. In a double-blind trial, one group received three mg melatonin and another group received placebo for two weeks at 10 PM. At the end of two weeks, sampling was performed to investigate the salivary level of cortisol under the same conditions. The research instrument was Pittsburgh questionnaire. Data were analyzed before and after intervention using SPSS 16 software. Results: Salivary levels of cortisol decreased significantly after the intervention in the melatonin group (melatonin: 1.40 ± 1.82 and placebo: 4.94 ± 4.43; P = 0.008). Salivary levels of cortisol in the morning after intervention were also lower in the melatonin group, but were not statistically significant (melatonin 3.99 ± 3.45 and placebo: 5.35 ± 4.9; P = 0.93). Also, the difference in salivary levels of cortisol at night and before and after intervention significantly decreased in melatonin group. PSQI difference (interventional dimension) and PSQI (before intervention) were significantly decreased in melatonin group (P = 0.0001). The rate of change in the subscales of sleep latency, sleep efficiency, and sleep disorders in the melatonin group than in the placebo group was significantly higher. Conclusion: Melatonin can be used as a safe and cost-effective treatment to improve sleep quality and can also reduce salivary cortisol increased in hemodialysis patients at night.