Midlife in the United States (MIDUS 3): Biomarker Project, 2017-2022

The Biomarker Project is one of multiple projects that comprise the MIDUS 3 (M3) "Integrative
Pathways to Health and Illness" study. For the past two decades, the overarching objective of
MIDUS has been to investigate linkages between sociodemographic, psychosocial, behavioral,
and neurobiological variables to account for unfolding profiles of morbidity and mortality across
the decades of adult life as well as the maintenance of good health and functional capacities. The
study has facilitated analyses that pay attention simultaneously to age, gender, race, and
socioeconomic variation in how psychosocial and neurobiological variables are linked. In
addition, the M3 data permit longitudinal assessment of the impact of ongoing historical events,
such as the 2008 economic recession, on the health of diverse-aged adults, which was also
included in the MIDUS Refresher 1 (MR1) assessments. M3 included recruitment of additional
twins to facilitate genomic analysis.
The M3 Biomarker Project (P4) includes assessment of multiple indicators of physiological
regulation/dysregulation and health according to the basic protocol implemented in the MR1
study, which repeated and expanded the M2 biomarker protocol. The M3 protocol included bone
density and body composition assessments at all sites and expansion of Actigraphy, Ankle
Brachial Index (ABI) and Gait assessments to all three sites. Data were collected during a
24-hour stay at one of three Clinical Research Units (CRU).