Late-onset hypogonadism (LOH) is a common syndrome in elderly men, characterized by decreased serum testosterone levels, manifesting as symptoms such as osteoporosis, erectile dysfunction, fatigue, sweating, and sleep disorders. With the growing elderly population, LOH is becoming a significant clinical issue affecting the health of elderly men. A large-sample study found that the overall estimated incidence of LOH in China is 7.8%, and hypogonadism is more common in elderly men, obese individuals, those with comorbidities, and males in poor health, often undertreated due to inadequate diagnosis Sleep plays a vital role in human life, closely linked to endocrine, neurological, and immune functions. Sleep disorders lead to reduced quality of life and are associated with increased cardiovascular disease risk and mortality posing a significant public health issue (7)Sleep disorders are primarily classified as insomnia, sleep-related breathing disorders (e.g., obstructive sleep apnea), hypersomnia, and parasomnias (e.g., non-rapid eye movement sleep disorders)(8). Recently, although the direct causality between LOH and sleep disorders has not been fully proven, studies suggest potential associations between them. As understanding of LOH deepens, testosterone is central to its pathogenesis, yet its role in sleep is rarely explored. Further understanding this relationship may help reveal the causes of certain health issues related to sleep disorders, aging, and shift work, guiding the treatment of LOH. This review elucidates the relationship between LOH and sleep disorders.

A literature review was conducted by searching PubMed, using keywords such as "late-onset hypogonadism" "hypogonadism" "sleep" "sleep disorders" "testosterone" and "testosterone replacement therapy"

LOH and sleep disorders mutually influence each other. Sleep disorders can affect serum testosterone levels, and testosterone can also impact sleep quality and sleep architecture. However, after eliminating the influence of body weight, this association may disappear, though further large-sample clinical trials are needed for confirmation.

There is a potential correlation between LOH and sleep disorders, with both influencing each other. Understanding this relationship is crucial for addressing LOH in patients, necessitating attention to their sleep quality and adopting appropriate measures to improve sleep disorders. Comprehensive treatment and management can enhance patients' quality of life and overall health.