Patterns and Life Course Determinants of Black-White Disparities in Biological Age Acceleration: A Decomposition Analysis

Despite the prom i nence of the weath er ing hypoth e sis as a mech a nism under ly ing racialized inequities in mor bid ity and mor tal ity, the life course social and eco nomic deter mi nants of Black-White disparities in bio log i cal aging remain inad- equately under stood. This study uses data from the Health and Retirement Study (n = 6,782), multivariable regression, and Kitagawa-Blinder-Oaxaca decomposition to assess Black-White disparities across three mea sures of bio log i cal aging: PhenoAge, Klemera-Doubal bio log i cal age, and homeo static dysregulation. It also exam ines the con tri bu tions of racial dif fer ences in life course socio eco nomic and stress exposures and vulnerability to those expo sures to Black-White disparities in bio log i cal aging. Across the outcomes, Black individuals exhibited accelerated biological aging rela- tive to White indi vid u als. Decomposition ana ly ses showed that racial differ ences in life course socio eco nomic expo sures accounted for roughly 27% to 55% of the racial disparities across the bio log i cal aging mea sures, and racial disparities in psy cho so cial stress expo sure explained 7% to 11%. We found less evi dence that het ero ge ne ity in the associations between social exposures and biological aging by race contributed substan- tially to Black-White disparities in bio log i cal aging. Our find ings offer new evi dence of the role of life course social expo sures in gen er at ing disparities in bio log i cal aging, with impli ca tions for under stand ing age pat terns of mor bid ity and mor tal ity risks.