Dynapenic obesity and incident cross-domain multimorbidity: A prospective study of three ageing cohorts.

BACKGROUND: We aimed to examine whether dynapenic obesity was associated with incident combinations of somatic morbidity, elevated depressive symptoms, and low cognitive performance. We hypothesized that participants with dynapenic obesity would have higher risks than those with neither obesity nor low grip strength.

METHODS: We analyzed 15,207 adults aged ≥45 years without baseline cross-domain multimorbidity from the China Health and Retirement Longitudinal Study (CHARLS), Health and Retirement Study (HRS), and English Longitudinal Study on Ageing (ELSA). Dynapenic obesity combined obesity with grip strength below cohort- and sex-specific 20th percentiles. Four exact incident patterns were evaluated using cohort-stratified Cox models adjusted for sociodemographic characteristics, smoking, and alcohol consumption.

RESULTS: During up to 7 years of follow-up, 2789 somatic-depressive-symptom, 1076 somatic-cognitive, 172 somatic-free depressive-symptom-cognitive, and 432 triple-domain events occurred. Compared with neither obesity nor low grip strength, dynapenic obesity was associated with somatic-depressive-symptom (hazard ratio [HR], 1.88; 95% confidence interval [CI], 1.55-2.28), somatic-cognitive (HR, 1.58; 95% CI, 1.20-2.08), and triple-domain patterns (HR, 3.17; 95% CI, 2.09-4.81). The somatic-free depressive-symptom-cognitive estimate was imprecise (HR, 0.29; 95% CI, 0.04-2.07). Findings for the three event-richer outcomes were generally maintained using clinical grip-strength thresholds and models addressing non-proportional hazards.

CONCLUSIONS: Dynapenic obesity was associated with greater risks of three incident cross-domain multimorbidity patterns. The somatic-free depressive-symptom-cognitive association remains uncertain and requires confirmation in larger samples.