Association between Gompertz law-based biological age and dementia: A longitudinal study of middle-aged and older Chinese adults

BackgroundWhile chronological age is a major but non-specific risk factor for dementia, measures of biological age based on physiological biomarkers may more accurately reflect systemic aging.ObjectiveWe aimed to assess the association between a Gompertz law-based biological age (Light BioAge) and incident dementia in a national cohort of middle-aged and older adults in China, and to evaluate the potential modifying role of lifestyle.MethodsWe conducted a longitudinal analysis of 5641 participants (≥45 years) from China Health and Retirement Longitudinal Study. Light BioAge was computed at baseline (2011) using a validated algorithm incorporating chronological age, serum creatinine, fasting glucose, and high-sensitivity C-reactive protein. Dementia in 2018 was determined via cognitive tests, informant reports, and functional assessment. Logistic regression models were used to estimate odds ratios (ORs).ResultsDuring the follow-up, 788 (13.97%) participants were identified as having dementia. Each 1-year increment in Light BioAge was associated with 4% higher risk of dementia (OR 1.04, 95% CI 1.03-1.05). Compared to low BioAge, participants with high BioAge had a more than two-fold higher risk of dementia (OR 2.38, 95% CI 1.85-3.04). This association persisted across strata of favorable and unfavorable lifestyles. Joint exposure analysis revealed that individuals with both high BioAge and an unfavorable lifestyle faced the highest risk (OR 2.96, 95% CI 2.05-4.27).ConclusionsAccelerated biological aging, quantified by Light BioAge, is a robust independent risk factor for dementia. Favorable lifestyle interventions offer potential strategies. However, findings require caution given the observational design and non-clinical dementia measure.