Association between abdominal muscle mass quantified by computed tomography and depression in middle-aged and older Korean men: a cross-sectional study of 2,877 cases

Background Depression is a prevalent mental health concern in aging populations and is associated with increased morbidity and reduced quality of life. While psychosocial and biochemical factors have been widely studied, the role of muscle mass, particularly abdominal muscle mass, in depression remains unclear. This study aimed to investigate the association between abdominal muscle mass, as measured by computed tomography (CT), and depression in middle-aged and older Korean men. Methods This retrospective cross-sectional study included 2,877 men aged ≥ 40 years who underwent both abdominopelvic CT and the Beck Depression Inventory (BDI) as part of a general health examination. Abdominal muscle mass was quantified using the total abdominal muscle area (TAMA) at the L3 vertebral level. Depression was defined as a BDI score ≥ 16. Multivariable logistic regression analyses were performed to examine the association between TAMA and depression, adjusting for age, body mass index, lifestyle factors, comorbidities, and biochemical markers. Results The prevalence of depression decreased across increasing TAMA quartiles ( p = 0.018). Higher TAMA was independently associated with a lower risk of depression. In the fully adjusted model, participants in the highest TAMA quartile had a significantly reduced odds of depression compared to those in the lowest quartile (adjusted OR, 0.534; 95% CI, 0.297–0.958; p = 0.035). Conclusion Greater abdominal muscle mass, as assessed by CT, was significantly associated with a lower prevalence of depression in middle-aged and older Korean men. These findings suggest that abdominal muscle mass may be a marker of mental health during aging.