Biopsychological burden phenotypes and cognitive performance in older Chinese and U.S. adults: an observational study using CHARLS and NHANES

BACKGROUND: Evidence on combined physiological-psychological burden phenotypes and cognition in older adults remains limited. We examined cross-sectional associations of burden phenotypes with global cognition and memory using CHARLS and NHANES. METHODS: Adults aged ≥60 years from CHARLS 2011 and NHANES 2011-2014 were included. A physiological dysregulation index incorporated cardiovascular, metabolic, inflammatory, and renal indicators; depressive symptoms were assessed using CES-D-10 in CHARLS and PHQ-9 in NHANES. Participants were classified as low burden, physiological burden, depressive symptoms, or dual burden. Survey-weighted regression, fixed-effect synthesis, and sensitivity analyses were performed. RESULTS: Complete phenotype data were available for 3977 CHARLS and 2558 NHANES participants. Physiological burden predominated in CHARLS, whereas low and physiological burden predominated in NHANES. In NHANES, dual burden was associated with lower global cognition and memory. In CHARLS, corresponding estimates were negative but statistically inconclusive. Fixed-effect synthesis showed associations of dual burden with poorer global cognition (β = -0.24, 95% CI: -0.34 to -0.14) and memory (β = -0.17, 95% CI: -0.28 to -0.07). These pooled estimates were considered supportive rather than definitive because only two datasets were available and measurements differed between cohorts. CONCLUSION: Burden phenotype distributions differed between older Chinese and U.S. adults. Dual burden was cross-sectionally associated with poorer cognitive performance, although association strength and precision varied by cohort. These findings support joint consideration of physiological dysregulation and depressive symptoms, but do not establish temporal or causal relationships.