Association of B-Type Natriuretic Peptide With Intrinsic Capacity Trajectories Among Chinese Older Adults.

BACKGROUND: Intrinsic capacity (IC) is central to healthy aging, yet accessible and cost-effective biomarkers for identifying individuals at risk of IC decline remain limited. We investigated whether elevated B-type natriuretic peptide (BNP), including persistent BNP abnormalities, is associated with baseline IC and longitudinal IC decline. METHODS: We conducted a population-based prospective cohort study using data from the Rugao Longevity and Aging Study, which included three waves of assessments over 4 years. IC was quantified as a composite score across five domains-mobility, vitality, cognition, psychological, and sensory-and assessed at baseline and follow-up visits. Longitudinal associations between BNP levels (quartiles, binary elevation, and cumulative abnormalities) and changes in IC were analyzed using generalized estimating equations. RESULTS: Among 1494 participants (mean [SD] age 77.9 [4.5] years, 46.4% male), higher BNP levels were significantly associated with lower IC scores at baseline (adjusted β = -0.46, 95% CI: -0.70, -0.22). In a longitudinal analysis, compared with the lowest quartile, the highest BNP quartile was associated with greater IC decline (adjusted β = -0.43; 95% CI: -0.70, -0.19). Elevated BNP was similarly associated with IC decline (adjusted β = -0.37; 95% CI: -0.57, -0.18). Findings remained significant among participants without CVD. Persistent BNP elevation at baseline and 2-year follow-up was associated with subsequent IC decline (adjusted β = -0.36; 95% CI: -0.65, -0.06). CONCLUSIONS: Elevated and persistent BNP abnormalities are consistently associated with IC decline, supporting BNP as a practical biomarker for early identification of older adults at risk of functional deterioration.