Relationship between sarcopenia and sleep status in female patients with mild to moderate Alzheimer's disease

Sleep disorders and sarcopenia could contribute to the development of Alzheimer's disease (AD), which are risk factors that rapidly deteriorate cognitive functions. However, few studies have evaluated the relationship between sarcopenia and sleep disorders in female AD patients, who have a higher prevalence than male patients. This study aimed to investigate the relationship between sarcopenia and sleep status in female patients with mild to moderate AD.This cross-sectional study recruited 112 female outpatients aged between 60 and 85 years. Demographic characteristics, appendicular skeletal muscle mass index (ASMI), grip strength, and gait speed were assessed. Sarcopenia was diagnosed according to criteria of the Asian Working Group for Sarcopenia. Pittsburgh Sleep Quality Index (PSQI) assessed sleep variables. Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) assessed cognitive function. Binary logistic regression models explored the relationship between sleep variables and cognitive function and sarcopenia, adjusting for potential cofounders.The outpatients were divided into 36 AD patients with sarcopenia (ADSa) and 76 AD patients without sarcopenia (ADNSa), with a prevalence of 32.1%. ADSa had lower ASMI, weaker grip strength, slower gait speed, a higher incidence of poor sleep quality and poorer cognitive function. Multivariate binary logistic regression analysis showed that high total scores of PSQI (odds ratio (OR) = 1.13), poor sleep quality (OR = 2.73), poor subjective sleep quality (OR = 1.83), low MMSE (OR = 0.77) and MoCA (OR = 0.76) scores were associated with high odds of sarcopenia. Compared to sleep time ≤ 15 min, >60 min (OR = 5.01) were associated with sarcopenia. Sleep duration <6 h (OR = 3.99), 8-9 h (OR = 4.48) and ≥9 h (OR = 6.33) were associated with sarcopenia compared to 7-8 h.More sleep symptoms and cognitive impairment exist in female patients with sarcopenia. The higher total scores of PSQI, poorer subjective sleep quality, longer sleep latency, excessive and insufficient sleep duration and poorer cognitive function are associated with higher odds of sarcopenia in female patients with mild to moderate AD.