Parental age and its influence on functional dependency and cognitive decline in older adults: a cohort analysis

OBJECTIVE: To explore the influence of parental age at childbirth on the long-term health of offspring. DESIGN: Prospective cohort study. SUBJECTS: The baseline data of the Chinese Health and Longevity Longitudinal Survey (CLHLS, 2008-2021) in 2008 and the subsequent follow-up data. EXPOSURE: Parental age at childbirth. MAIN OUTCOME MEASURES: Functional independency (assessed by Activities of daily living, ADL), cognitive function (assessed using Mini-Mental State Examination, MMSE), and all-cause mortality. RESULTS: Offspring with advanced maternal age (≥ 37 years) were associated with higher odds of ADL limitations (OR = 1.39, 95%CI = 1.04-1.84) and cognitive dysfunction (OR = 1.34, 95%CI = 1.02-1.76). Conversely, advanced paternal age (≥ 43 years) demonstrated negative associations with ADL limitation (OR = 0.52, 95%CI = 0.36-0.73) and cognitive dysfunction (OR = 0.60, 95%CI = 0.43-0.83). While no direct association emerged between parental age and offspring mortality, we identified a significant trend toward reduced mortality risk with increasing paternal age, particularly among offspring of non-educated parents (P for trend = 0.02). Notably, the presence of sibling caregiving was associated with attenuated maternal age-related health risks, indicating a potential moderating role of family support structures. CONCLUSION: Our study identifies observational associations between parental age and offspring health outcomes in later life. Specifically, older maternal age associated with poor health outcomes while older paternal age was associated with better health outcomes in offspring. As societies grapple with aging populations and declining fertility, our study suggests the need for integrated health and social policies that support families in this changing demographic landscape.