A Cross-Sectional Study Examining the Correlation between Nocturnal Melatonin Level and Sleep Quality in Patients Admitted To the Cardiac Care Unit

Abstract

BACKGROUND:Quality of sleep, as a basic need, is an important factor for surviving patients in hospitals. Many factors may contribute to disturbing patients sleep, such as continuous ambient light, is required for healthcare providers to monitor patients. Ambient light can influence patients’ quality of sleep due to melatonin secretion.AIM:Study aimed to determine the correlation between nocturnal melatonin levels and sleep quality in patients admitted to the Cardiac Care Units (CCU).MATERIAL AND METHODS:This cross-sectional study was done on inpatients of CCUs at Amir-Almomenin Hospital in Kordkoy city, a cardiac referral hospital in the northeastern of Iran in 2015. Sixty-eight inpatients were selected through convenience sampling. Before data gathering light level of CCUs was measured every one hour in 2 days, the quality of nocturnal sleep was investigated through Verran and Snyder-Halpern (VSH) Sleep Scale at the second night of admission urinary melatonin level was measured at the same night in all urine excreted between 22:00 pm and 07:00 am.RESULTS:The mean and standard deviation (SD) score of sleep quality in three dimensions of sleep disturbance, sleep effectiveness and sleep supplementation were 336.6 ± 149.9, 269.0 ± 82.2, and 175.2 ± 30.7, respectively. Also, the mean and SD of nocturnal urinary melatonin levels was 323.02 ± 136.21 pg/ml. There was not a significant correlation between level of nocturnal melatonin and three domains of sleep quality; sleep disturbance (r = 0.005, P = 0.968), sleep effectiveness (r = 0.090, P = 0.464), and sleep supplementation (r = -0.037, P = 0.763).CONCLUSION:According to the result, most CCUs patients suffer from sleep disturbance. However, there was no correlation between the level of melatonin and sleep quality. There is a need for recognising the reasons for sleep disturbances in Cardiac Care Units. It is imperative for care providers to be able to recognise the causes of sleep disturbances and to modify environmental factors such as ambient light to improve sleep quality in hospitalised patients.

Dark nighttime interventions and sleep quality in intensive care unit patients: A systematic review and meta‐analysis

“…In this review, it is intuitive to think that specific measures to protect and stimulate the pineal gland with cycled lighting regulation in the ICU are capable of causing an increase in the endogenous production of this sleep‐regulating hormone, and in fact, three studies 17,21,23 measured this outcome, but none of them showed a statistical difference in urinary or plasma melatonin levels between intervention and control groups, which is intriguing and suggests that factors beyond cycled lighting may be related to melatonin production rhythm and intensity in critically ill patients 33,34 . However, in the study by Arık et al, 17 urinary melatonin levels were significantly higher after the first night of intervention in the experimental group compared with the baseline (pre‐intervention).…”

The effect of melatonin on quality of sleep in patients with sleep disturbance admitted to post coronary care units: a randomized controlled trial

“…Hospital admission is another factor, which can increase the risk of sleep disturbances [9]. Accordingly, patients admitted to coronary care unit (CCU) are reported to have a poor quality of sleep, because of the underlying cardiac condition, effect of medications, hospital conditions, and stress and anxiety that they experience [10][11]. Considering that poor sleep quality is stressful, it can stimulate the release of epinephrine and norepinephrine, which consequently can be associated with tachycardia, tachypnea, increased myocardial oxygen requirements, and eventually leads to severe ischemia and MI [12].…”