Higher plasma melatonin levels are associated with slightly greater objective sleep efficiency but not with subjective sleep quality in adults aged 25-65 years.
In a cross-sectional study of 334 adults (mean age 43 years), plasma melatonin levels showed no significant association with Pittsburgh Sleep Quality Index scores, but higher melatonin levels were linked to slightly greater sleep efficiency measured by actigraphy. Mean plasma melatonin concentration was 14.5 ± 15.9 pg/mL, with higher levels in men and a decreasing trend with age.
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Higher plasma melatonin levels are associated with slightly greater objective sleep efficiency but not with subjective sleep quality in adults aged 25-65 years. The current body of evidence comprises 1 study. EvidenceHub rates the overall confidence at 9/100 (low).
The Claim
Higher plasma melatonin levels are associated with slightly greater objective sleep efficiency but not with subjective sleep quality in adults aged 25-65 years.
This conclusion is most relevant to: Adults aged 25-65 years from Salamanca and Ávila, Spain.
What the Research Shows
The conclusion draws on 1 linked study. Highlights from the cited literature:
- ▸Plasma Melatonin Levels, Seasonal Variation, and Sleep Quality: A Stratified Analysis of Adults Aged 25-65 Years Using the Pittsburgh Sleep Quality Index and Actigraphy. (International journal of molecular sciences, 2026) —
How It Works
The proposed biological pathway:
- ▸Melatonin is a hormone regulating circadian rhythms
- ▸Higher melatonin levels may promote sleep onset and maintenance
- ▸Objective sleep efficiency (actigraphy) captures actual sleep continuity
- ▸Subjective sleep quality (PSQI) is influenced by multiple factors beyond melatonin
Who Might Benefit
Evidence fit by population:
- ▸Adults aged 25-65 years from Salamanca and Ávila, Spain
Recommended Dose
N/A
Limitations & Caveats
Important context when interpreting this evidence:
- ▸Cross-sectional design prevents causal inference
- ▸Seasonal variation in melatonin levels was not statistically significant, limiting interpretation
- ▸Only 334 of 500 participants had valid melatonin measurements, potential selection bias
Frequently Asked Questions
Does higher melatonin improve sleep quality in adults?▼
This study found no association between plasma melatonin levels and subjective sleep quality (PSQI), but higher levels were linked to slightly better objective sleep efficiency measured by actigraphy.
What was the average melatonin level in this study?▼
The mean plasma melatonin concentration was 14.5 ± 15.9 pg/mL, with higher levels in men and a decreasing trend with age.
Did melatonin supplements help sleep in this study?▼
Participants reporting melatonin supplement use had higher PSQI scores (worse subjective sleep) and lower total sleep time compared to non-users, suggesting no benefit.
Was there a seasonal effect on melatonin levels?▼
A trend toward higher melatonin levels during winter was observed, but the differences were not statistically significant.
References
- 1.Garcia-Yu IA, Crespo-Sedano A, Jiménez-Vaquero C, Gonzalez-Sanchez J, Alonso-Dominguez R, Sanchez-Aguadero N, Recio-Rodriguez JI. “Plasma Melatonin Levels, Seasonal Variation, and Sleep Quality: A Stratified Analysis of Adults Aged 25-65 Years Using the Pittsburgh Sleep Quality Index and Actigraphy..” International journal of molecular sciences, 2026. PMID: 42511663 DOI: 10.3390/ijms27146320