Gender Differences in Sleep Structure and Circadian Rhythms: A Biological, Hormonal, and Genetic Perspective

Abstract

Sleep and circadian rhythms are fundamental biological processes crucial for maintaining physiological functions and overall health. Growing evidence indicates significant sex differences in the regulation of sleep structure and circadian rhythms, stemming from complex interactions among biological mechanisms. This review systematically analyzes sex-based variations in sleep parameters (including NREM-REM cycles, sleep efficiency, and fragmentation) and circadian traits (such as phase preference and clock gene expression). It delves into the specific mechanisms of neuroendocrine regulation involving the suprachiasmatic nucleus (SCN) and sex hormones (estrogen, progesterone, testosterone). The findings indicate that women often exhibit greater circadian robustness but report more subjective sleep complaints, while men show a higher risk of objective sleep fragmentation. Genetic factors, such as the PER3 VNTR and CLOCK 3111T/C polymorphisms, demonstrate differential distribution and effects between sexes, with epigenetic mechanisms further shaping sex-specific sleep patterns. This review underscores the necessity of integrating sex as a critical variable in sleep research and clinical practice. It provides a theoretical foundation for developing sex-specific interventions for sleep disorders, thereby enhancing the efficacy of chronotherapy and precision sleep medicine.