J Gerontol B Psychol Sci Soc Sci. 2026 Oct 1;81(Supplement_2):S125-S138. doi: 10.1093/geronb/gbag153.
ABSTRACT
OBJECTIVES: Gerontological and population health sciences increasingly emphasize life-course, biosocial frameworks linking social environments to biological aging and disease processes, for which high-quality biological data are essential. We report on the collection, assay, and quality of aging-related biomarkers in the National Longitudinal Study of Adolescent to Adult Health (Add Health) Waves V and VI.
METHODS: Staff collected blood specimens during in-home health exams, processed them locally, and shipped them to the lab for further processing, assay completion, and archiving. Analytes assessed cardiovascular disease risk, glucose homeostasis, lipids, renal function, hepatic injury, inflammation, immune system processes, and neurodegeneration. Inter-assay coefficients of variation (CVs) were estimated for sample sets. In 2% of participants, a duplicate specimen was collected within 2 weeks and assays repeated; intraclass correlation coefficients (ICCs) were calculated to assess short-term reliability.
RESULTS: Wave V collected blood from 92% of 5,381 participants who completed the exam (mean age 38); Wave VI collected blood from 91% of 6,073 participants (mean age 44). Reliability was excellent (ICC ≥ 0.75) and highest for hemoglobin A1c at Waves V-VI and GFAP and HSV and SARS-CoV-2 serologies at Wave VI. Reliability was fair to good (ICC 0.40 to <0.75) for assays of low-abundance proteins reflecting temporally dynamic biological processes; none were poor (ICC < 0.40). CVs were desirable (<10%) for established clinical chemistry assays but less so (≥10%) for low-abundance proteins, markers of temporally dynamic biological processes, and SARS-CoV-2.
DISCUSSION: High-quality biological data from Add Health Waves V and VI greatly expand the study's capacity to support life-course, biosocial research.
PMID:42837503 | DOI:10.1093/geronb/gbag153