Association between sleep disorders and low muscle mass based on body composition metrics.

Investigating the relationship between body composition and sleep disorders, this cross-sectional study analyzed 990 patients (427 males, 563 females) at the Samsung Medical Sleep Center using polysomnography and bioelectrical impedance analysis. Sleep disorders were classified as primary insomnia (PI), comorbid insomnia and sleep apnea (COMISA), and obstructive sleep apnea (OSA) using ICSD-3 criteria, while sarcopenia was defined using gender-specific Skeletal Muscle Index (SMI) thresholds. The PI group showed the lowest SMI values across both sexes. Analysis revealed that among PI patients, prolonged sleep latency was significantly associated with sarcopenia. Among sarcopenic participants, patients with COMISA, particularly males, tended to show higher BMI, body fat percentage, and fat mass index compared to controls. The findings demonstrate distinct patterns: PI patients exhibited sarcopenia associated with poor sleep quality, while COMISA and OSA patients showed features consistent with sarcopenic obesity. These results suggest the need for targeted interventions: PI patients would benefit from strategies focusing on sleep quality improvement and muscle mass preservation, while OSA and COMISA patients require comprehensive approaches addressing both weight management and muscle mass maintenance.