"Urological age" as a proxy of healthy longevity: analysis of prospective population-based cohorts in U.S. and China.

Background: Assessing urinary symptoms poses a complex challenge for primary care practitioners. In evaluating urological function, our approach involves constructing an urological age through the analysis of laboratory parameters and indicators of the urinary system.

Methods: Based on the National Health and Nutrition Examination Survey (NHANES), urological laboratory tests and age-related symptoms were included in the development of urological age (UA) and urological age acceleration (UAA) through the Klemera Doubal method. In relation to mortality associated with UAA, the metric was categorized into grades (0, 1, 2) as a discrete variable. We investigated the correlation between UAA and its grades with mortality, conducted survival analysis based on UAA grades, and explored the correlation between multisystem ageing-related disorders and UAA grades based on the NHANES and the West China Natural Population Cohort Study.

Results: UA was related to age with the r to 0.85 in men and 0.84 in women. Each year the increase in UAA was related to higher 1% and 4% mortality for men and women. Those with UAA grades 1 and 2 were associated with more risk of mortality than individuals with UAA grade 0 (men 8% and 40%, women 24% and 157%). The advanced UAA grades kept pace with multisystem ageing. Healthy diets and lifestyle habits are associated with lower UAA.

Conclusion: Urological age is related to multisystem ageing and increases mortality risk, and urological age can be used to screen high-risk individuals and inform precision clinical development for ageing intervention.