Relationship Between Appendicular Skeletal Muscle Mass and Depression Among Adults With Prior Head Injury and Loss of Consciousness: Results From the NHANES 2011–2014

ObjectiveHead injury often causes depression, yet risk factors remain poorly understood. Muscle mass, linked to metabolic and neuroendocrine functions, may influence depression among adults with prior head injury and loss of consciousness (DPHI-LOC), but evidence is lacking.MethodsA cross-sectional analysis was conducted using data from the 2011-2014 National Health and Nutrition Examination Survey. The Appendicular Skeletal Muscle Mass Index (ASMI) was used to quantify muscle mass, and depressive symptoms were measured by the 9-item Patient Health Questionnaire (PHQ-9). Weighted multivariate logistic regression and propensity score matching (PSM) were used to evaluate associations between low muscle mass and DPHI-LOC, adjusting for demographic, socioeconomic, and clinical confounders. Subgroup analyses and interaction tests examined effect modifications across strata.ResultsAmong 2361 adults with head injuries, 232 (8.8%) were reported with DPHI-LOC. Low ASMI was independently associated with an elevated DPHI-LOC risk (adjusted OR = 2.35, 95% CI = 1.24∼4.46, <i>P</i> = 0.020). PSM analysis confirmed a 2.82-fold increased likelihood of depression in participants with low muscle mass (95% CI: 1.54∼4.09, <i>P</i> = 0.007). Subgroup analyses demonstrated that there were no significant effect modifications.ConclusionReduced muscle mass is a significant correlate of DPHI-LOC. These findings suggest that preservation of muscle mass may help to mitigate risk of depression after head injury.