Applying a Proteomic Aging Clock to Data from a Very Long-Running Epidemiological Study
Older epidemiological study data sometimes offers the potential for reanalysis with modern aging clock algorithms to assess biological age. If the study continued since the data was obtained, then there is the possibility to demonstrate that measures of biological age do correlate well with specific long-term outcomes. The downside is that researchers are limited by past choices regarding what was measured, and thus which clocks can be used, and often limited in the degree to which data obtained decades ago remains accessible. Nonetheless, sometimes it works out and we see results such as those reported here. A study has followed one birth cohort since the late 1940s, and proteomic data was obtained 15 years ago. That data has now been used to assess biological age at that time, then correlated with later medical outcomes over the following 15 year span of time.
The pace of organ ageing varies substantially between individuals, yet drivers of variability remain poorly understood. This gap is critical, given only 20-30% of longevity is genetically inherited and age-related diseases are leading causes of morbidity and mortality. Proteomic clocks allow organ ageing to be estimated from blood sampling, facilitating study of how life course exposures shape biological ageing heterogeneity. Here, we leverage the unique design of the MRC National Survey of Health and Development (NSHD), the world's oldest continuously followed birth cohort, to track 1,803 individuals across eight decades since birth in 1946.
At mean age 63.2 years, we estimated proteomic ageing in seven organs. Despite near identical chronological ages, participants' proteomes revealed biological ageing disparities spanning decades. Extreme ageing in multiple organs was a strong prognostic indicator for all-cause mortality over the following 15 years (hazard ratio 6.62 for ≥ 4 extremely aged organs).
Adversity and being overweight in adolescence associated with accelerated ageing decades later in life. Completing secondary school education and maintaining physical activity linked to relative biological youth. Mediation analyses indicated liver, kidney, and immune ageing linked life course exposures to mortality. Across 10,776 plasma protein targets, we identified 143 predictors of longevity, including MED9, strongly linked to diverse socio-behavioural exposures. These findings provide unique insights into which factors are likely to shape how we age, when in life they may be influential, and how biological effects emerge, informing healthy ageing promotion.