Social determinants of health and sarcopenia in adults: Insights from the National Health and Nutrition Examination Survey

Although sarcopenia is associated with various factors, the specific relationship between social determinants of health (SDoH) and sarcopenia, as well as mortality, remains unclear. This study seeks to examine how SDoH relates to both sarcopenia and mortality in individuals diagnosed with sarcopenia. The National Health and Nutrition Examination Survey provided data covering the period from 2003 to 2006. Assessment of sarcopenia was conducted using dual-energy X-ray absorptiometry. The SDoH factors considered encompassed education, marital status, household income, food security, health insurance coverage, employment status, home ownership, and healthcare access. Weighted multivariate logistic regression was applied in a cross-sectional analysis to estimate the association between SDoH and sarcopenia, while restricted cubic spline (RCS) regression was used to assess potential nonlinearity. Cox proportional hazards models and RCS were employed in the cohort study to investigate the associations between SDoH and all-cause as well as premature mortality. This analysis comprised 5210 participants in total. Cross-sectional analysis revealed that as SDoH scores increased as a continuous variable, the likelihood of sarcopenia significantly rose (odds ratio [OR] = 1.163, 95% confidence interval [CI]: 1.065–1.270, P = .003). When categorized variable, compared to participants with lower SDoH scores (category: none), those with higher scores (category: 6) were more susceptible to sarcopenia (OR = 2.250, 95% CI: 1.085–4.667, P = .034). The RCS curve suggested that SDoH was positively and linearly associated with the likelihood of developing sarcopenia. The cohort study revealed that among individuals with sarcopenia, higher SDoH scores were associated with an increased probability of all-cause mortality (adjusted hazard ratio [aHR] = 1.20, 95% CI: 1.10–1.30, P < .0001) and premature mortality (aHR = 1.41, 95% CI: 1.25–1.59, P < .0001). The RCS curve indicated that SDoH was significantly and positively linearly related to both all-cause and premature mortality in individuals at high risk for sarcopenia. Findings from this study demonstrated a notable association between SDoH and sarcopenia. Adverse SDoH are associated with increased all-cause and premature mortality. Developing innovative public health policies and interventions addressing SDoH is essential to mitigating sarcopenia and reducing mortality in affected populations.