Melatonin Supplementation for Six Weeks Had No Effect on Arterial Stiffness and Mitochondrial DNA in Women Aged 55 Years and Older with Insomnia: A Double-Blind Randomized Controlled Study.
Study Goal
The researchers aimed to investigate whether melatonin supplementation improves arterial stiffness, mitochondrial DNA copy number, and insulin resistance in older women with insomnia.
Results Summary
The study found no evidence that melatonin improved cardiometabolic parameters like arterial stiffness, mtDNA, or insulin resistance, but sleep quality was improved in the melatonin group.
Population
Healthy women aged 55 years and older with untreated insomnia (PSQI ≥ 5).
Effective Dosage
2 mg melatonin every night.
Duration
Six weeks.
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
melatonin supplementation | increase | sleep quality index using PSQI | healthy women aged 55 years and older with insomnia | from a score of 11 to 8 | improved | #1 |
melatonin supplementation | no change | arterial stiffness | healthy women aged 55 years and older with insomnia | - | no evidence that ... improved | #2 |
melatonin supplementation | no change | mtDNA copy number in white blood cells | healthy women aged 55 years and older with insomnia | - | no evidence that ... improved | #3 |
melatonin supplementation | no change | insulin resistance (HOMA-IR) | healthy women aged 55 years and older with insomnia | - | no evidence that ... improved | #4 |
UNLABELLED: Melatonin is a hormone produced in the pineal gland that controls sleep and circadian rhythm. Some studies have reported antioxidant and anti-inflammatory effects of melatonin that could benefit cardiometabolic function; however, there is a lack of evidence to support these assertions. The aim of this study was to investigate whether melatonin has beneficial effects on arterial stiffness and mitochondrial deoxyribonucleic acid (DNA) in humans. METHODS: This study was designed as a double-blind randomized controlled study. Thirty-eight healthy women aged 55 years and older were enrolled. All had insomnia (Pittsburgh Sleep Quality Index (PSQI) ≥ 5), not treated with any medications, for at least three months before enrollment. Subjects were divided into a melatonin and a placebo group according to melatonin supplementation. The melatonin group took 2 mg melatonin every night for six weeks. The cardio-ankle vascular index (CAVI) was used as an indicator of arterial stiffness. After six weeks, CAVI, mitochondrial DNA (mtDNA) copy number in white blood cells (WBCs), and other metabolic indices, such as homeostasis model assessment of insulin resistance (HOMA-IR), were checked. RESULTS: Sleep quality index using PSQI was improved in the melatonin group from a score of 11 to 8 ( CONCLUSIONS: We found no evidence that melatonin supplementation improved cardiometabolic parameters like arterial stiffness, mtDNA, or insulin resistance compared to the placebo between baseline and week six. Sleep quality was improved in the melatonin group. Further research, including longer-term studies with higher doses of melatonin, is warranted.