Objective
This study aims to estimate the prevalence of early-onset sarcopenia and sarcopenic obesity in the United States and its relative risk due to obstructive sleep apnea (OSA).
Methods
Data in this cross-sectional study were extracted from the National Health and Nutritional Examination Survey (NHANES) 2015–2018(n = 4037). Individuals with missing information on the sleep disorder questionnaire, dual-energy x-ray absorptiometry examination, and other relevant variables were excluded. Early-onset sarcopenia and sarcopenic obesity were defined as those aged 18–39 according to FNIH (Foundation for the National Institutes of Health) criteria and previous studies. A weighted multistage stratified probability sampling design was considered to estimate the prevalence of early-onset sarcopenia and sarcopenic obesity. Weighted multivariable logistic regression analyses were performed to evaluate the association between OSA and early-onset sarcopenia. Weighted multivariable mediation models were applied to analyze the mediation effect of markers of chronic inflammation (serum chronic reaction protein, CRP), insulin resistance (homeostasis model assessment insulin resistance index, HOMA-IR), dietary quality (health eating index, HEI) and body mass (body mass index, BMI) on the association between OSA and early-onset sarcopenia.
Results
This observational study included 4037 participants (aged 18–59). Among them, 2162 participants aged 18–39 could represent 52.2 million noninstitutionalized residents of the same age in the United States. The prevalence of early-onset sarcopenia and early-onset sarcopenic obesity was estimated to be 5.6% and 4.6%, according to the multistage weighted survey design of NHANES. A higher prevalence of sarcopenia (12% V.S. 5.5%, P < 0.01) and sarcopenic obesity (10.3% V.S. 4.0%, P < 0.01) was observed among participants with OSA than those without OSA. Multivariable logistic regression models suggested that participants with OSA had higher odds ratios of suffering from early-onset sarcopenia [Odds Ratio (OR): 2.7, 95% confidence interval (CI):1.4–5.1] and early-onset sarcopenic obesity [OR: 3.0, 95% CI: 1.5-6.0] after adjusting for potential confounding variables including demographics, socioeconomic level, lifestyle, and comorbidities. Mediation analyses suggested CRP mediated 30.3% (P < 0.01), HOMA-IR mediated 10.3% (P < 0.01), BMI mediated 53.6% (P < 0.05), HEI mediated 8.6% (P < 0.01) of the potential effects of OSA on early-onset sarcopenia respectively.
Conclusion
Early-onset sarcopenia and sarcopenic obesity were prevalent among young adults in the US. OSA is a significant independent risk factor and may induce muscle loss by unhealthy diet habits, high BMI, inducing chronic inflammation, or insulin resistance. Given the progressive process of early-onset sarcopenia, it was essential for clinicians to arrange appropriate screening and interventions for patients with OSA to prevent muscle loss as early as possible.