Researchers in Israel have identified differences in muscle structure among individuals with obstructive sleep apnea (OSA). A study published in the journal Sleep and Breathing found that people with OSA generally exhibit a higher muscle mass index, indicating more muscle area relative to height, but this muscle is often less dense.
Read More
The research involved data from 209 adults who participated in overnight sleep studies and underwent chest or abdominal CT scans. Compared to a control group, participants with OSA were typically older, predominantly male, heavier, and more likely to suffer from hypertension, cardiovascular disease, and reduced oxygen levels during sleep. While those with OSA showed increased muscle mass, the quality of that muscle was diminished.
The study revealed a significant correlation between OSA and an elevated muscle mass index, though lower muscle density was more closely associated with factors like age and weight rather than with OSA itself. Severity of OSA was linked to decreased skeletal muscle density (SMD) and increased skeletal muscle index (SMI), suggesting larger but less dense muscle mass. Higher body mass index (BMI) was also strongly linked to lower SMD and higher SMI, with the most significant connections observed in individuals over 60 years old and those with a BMI exceeding 30.
Dr. Wendy Troxel, a clinical psychologist and senior behavioral scientist, indicated that while individuals with OSA may have more muscle mass, it could be less healthy due to increased fat content, which may affect strength and metabolic function. She noted an important relationship between OSA severity and muscle quality, which, although modest, hints at broader metabolic risks. Troxel emphasized that OSA extends beyond a nighttime breathing disorder and may highlight metabolic dysfunction impacting various bodily systems, including muscle health.
Study co-author Ariel Tarasiuk from Ben-Gurion University of the Negev described the findings as "paradoxical," noting that age and obesity appeared to have a more significant effect on muscle health than OSA itself. He urged patients to recognize that sleep apnea affects overall health, including muscle function, not just sleep quality. Tarasiuk advocated for getting properly diagnosed and treated, including the use of CPAP therapy, which can improve breathing and sleep.
He also pointed out the critical need to maintain a healthy weight and stay physically active to enhance muscle health and mitigate sleep apnea severity. Tarasiuk advised clinicians that larger muscles are not always healthier if they contain fat, which can hinder strength and performance. He highlighted the need for a comprehensive approach that treats airway issues while addressing weight, physical activity, and metabolic health.
The study's findings may not apply to all populations as it was conducted at a single center, and the researchers lacked information on lifestyle factors such as physical activity, diet, smoking, or alcohol consumption, which can impact muscle health. Tarasiuk expressed optimism for larger, multi-center studies in the future to validate these findings and explore how muscle changes develop over time in individuals with sleep apnea.