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.

Int J Mol Sci · 2026 · PMC13409838 · PMID 42511663

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a decreasing trendno p-value reported

Mean plasma melatonin concentration was 14.5 ± 15.9 pg/mL, with higher levels observed in men than women and a decreasing trend with age.

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