Associations between essential trace elements and sleep quality in Iranian adults based on the Pittsburgh Sleep Quality Index
摘要
Sleep is a fundamental physiological process essential for maintaining both physical and mental well-being. Various biological, environmental, and nutritional factors influence sleep quality, with recent studies focusing on the role of trace elements. Therefore, this study aims to investigate the individual and combined effects of serum levels of essential trace elements—specifically magnesium (Mg), calcium (Ca), iron (Fe), manganese (Mn), cobalt (Co), copper (Cu), zinc (Zn), and selenium (Se)—on sleep quality among Iranian adults, utilizing the Pittsburgh Sleep Quality Index (PSQI). This cross-sectional study involved 99 individuals with sleep disorders who were referred to Farabi Hospital between October 2024 and February 2025. Sleep quality among participants was assessed using the PSQI, while serum levels of essential elements were analyzed through inductively coupled plasma mass spectrometry (ICP-MS). The study’s findings revealed a negative correlation between Fe concentration and total PSQI scores (Beta = − 0.02, 95% CI − 0.03 to 0.00, P = 0.03). Higher levels of Fe were associated with a reduced risk of poor subjective sleep quality (OR 0.984, 95% CI 0.971 to 0.995, P = 0.009) and shorter sleep latency (OR 0.986, 95% CI 0.972–0.990, P = 0.03). Additionally, an increase in Fe concentration correlated with improved habitual sleep efficiency (OR 0.984, 95% CI 0.968 to 0.997, P = 0.02). Using the quantile g-computation model, Fe was identified as the most significant factor influencing the overall PSQI score. Furthermore, the generalized additive model indicated notable non-linear relationships between Co and the global PSQI score (P = 0.02), as well as between Zn and the global PSQI score (P = 0.034). In conclusion, the results highlights that individuals with low serum Fe levels face a considerably higher risk of poor sleep quality. Additionally, Co concentration was found to exert a significant negative effect on the global PSQI score, further pointing to the importance of trace elements in sleep health.