The effect of magnesium supplementation on primary insomnia in elderly: A double-blind placebo-controlled clinical trial.
Level 2 - randomized trial
Individual double-blind randomized placebo-controlled trial
What was done
A double-blind randomized controlled trial evaluated 46 elderly participants with primary insomnia allocated to receive either 500 mg magnesium daily or a placebo for 8 weeks. Assessments at baseline and after 8 weeks included the Insomnia Severity Index (ISI), sleep logs, physical activity, 3-day 24-hour dietary recalls, and blood biomarkers (serum magnesium, renin, melatonin, and cortisol).
What was found
Compared to placebo, magnesium supplementation resulted in statistically significant increases in sleep time (P = 0.002), sleep efficiency (P = 0.03), serum renin (P < 0.001), and serum melatonin (P = 0.007). It led to significant reductions in ISI score (P = 0.006), sleep onset latency (P = 0.02), and serum cortisol concentration (P = 0.008). Reductions in early morning awakening (P = 0.08) and increases in serum magnesium (P = 0.06) were marginally significant. Total sleep time did not differ significantly between groups (P = 0.37). Exact numerical values for these outcomes were not reported in the abstract.
Why it matters
This trial suggests that 500 mg daily magnesium may serve as an affordable, low-risk nutritional intervention to improve subjective sleep quality and modulate neuroendocrine markers in older adults suffering from insomnia.
Limits
The study had a small sample size (n = 46) and short duration (8 weeks). Sleep outcomes relied on subjective logs and surveys rather than objective measures like polysomnography or actigraphy. The abstract did not report absolute numerical values or effect sizes, providing only p-values.
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- context Magnesium enhances sleep quality by supporting GABA neurotransmission in the brain.