Age‐Stratified Associations of Sarcopenic Obesity With Mortality in Type 2 Diabetes

BACKGROUND: Sarcopenic obesity, the coexistence of sarcopenia and obesity, has been linked to adverse health outcomes due to comorbidity. Evidence on the association between sarcopenic obesity and mortality among individuals with Type 2 diabetes remains limited METHODS: Sarcopenic obesity was defined using Japan Working Group on Sarcopenic Obesity criteria. Participants were divided into four groups based on the presence of sarcopenia and obesity. Cox proportional hazards models evaluated the mortality risk. Subgroup analyses were performed by age (40-75 vs. >75 years). Sensitivity analysis was performed by dichotomizing participants into sarcopenic obesity and non-sarcopenic obesity groups. RESULTS: Of the 799 participants (mean age 68.6 years, 59.3% men), proportions of neither sarcopenia nor obesity, obesity alone, sarcopenia alone and sarcopenic obesity were 56.2%, 34.5%, 6.3% and 3.0%, respectively. During a median follow-up of 46 months, 41 deaths occurred. Compared with neither of them, the adjusted hazard ratios (aHRs) (95% CI) of mortality in obesity alone, sarcopenia alone and sarcopenic obesity were 0.53 (0.18-1.57) (p = 0.25), 2.36 (0.99-5.6) (p = 0.053) and 2.89 (1.01-8.30) (p = 0.048), respectively. Age-stratified analyses revealed that sarcopenic obesity markedly increased mortality risk in participants aged 40-75 years (aHR 13.1 [2.93-58.4], p < 0.001), whereas sarcopenia alone (aHR 3.21 [1.07-8.33], p = 0.004), but not sarcopenic obesity (aHR 1.41 [0.34-8.81], p = 0.51), was associated with increased mortality in those aged > 75 years. Compared with non-sarcopenic obesity, sarcopenic obesity had a significantly higher hazard ratio for mortality (aHR 4.0 [1.44-11.0], p = 0.008). In age-stratified analysis, this association remained significant in participants aged 40-75 years (aHR 14.1 [3.25-61.5], p < 0.001), but not in those aged > 75 years (aHR 1.55 [0.32-7.46], p = 0.59) (interaction p = 0.03). CONCLUSIONS: In Japanese individuals with Type 2 diabetes, sarcopenic obesity was significantly associated with increased mortality risk. This relationship was particularly pronounced in individuals aged 40-75 years, whereas sarcopenia alone was associated with increased mortality risk rather than sarcopenic obesity in individuals aged > 75.