Dynapenic metabolic syndrome phenotypes and depression in older adults: A nationwide population-based study

While metabolic syndrome (MetS) and dynapenia are prevalent in older adults, their combined association on mental health remains unclear. This study aimed to examine the relationship between dynapenic MetS phenotypes and prevalent depression in Korean adults aged ≥65 years.

We used data from 2162 individuals aged ≥65 years from the Korea National Health and Nutrition Examination Survey. Participants were classified into four phenotypic groups according to the presence or absence of dynapenia and MetS. Depression was defined as either a self-reported physician-diagnosed depression with current antidepressant use, or a total score of ≥10 on the Korean version of the Patient Health Questionnaire-9.

Among 2162 individuals, 382 had depression (weighted prevalence 16.9%). In the fully adjusted model, compared with the group without MetS and dynapenia, higher odds of depression were observed in those with dynapenia alone (odds ratio [OR] 1.96, 95% confidence interval [CI]: 1.25-3.08) and in those with both dynapenia and MetS (OR 1.97, 95% CI: 1.29-3.00), but not in those with MetS alone. The associations for dynapenia alone (OR 1.92, 95% CI: 1.19-3.12) and dynapenia with MetS (OR 1.92, 95% CI: 1.20-3.07) remained significant after excluding individuals with severe illnesses.

Dynapenia, alone or in combination with MetS, was significantly associated with prevalent depression in older Korean adults, whereas MetS alone showed no significant association. Muscle strength may play an important role in late-life mental health.