Background: Temporal variability of biomarkers should be evaluated prior to their use in epidemiologic studies.

Methods: We evaluated the reproducibility, using intraclass correlation coefficients (ICCs), of 77 plasma and 9 urinary biomarkers over 1–3 years among premenopausal (n=40) and postmenopausal (n=35–70) participants from the Nurses’ Health Study (NHS) and NHSII.

Results: Plasma and urinary stress hormones and melatonin were measured among premenopausal women while melatonin and the remaining biomarkers were measured in postmenopausal women. ICCs were good to excellent for plasma carotenoids (0.73–0.88), vitamin D analytes (0.56–0.72), bioactive somatolactogens (0.62), soluble leptin receptor (0.82), resistin (0.74), and postmenopausal melatonin (0.63). Reproducibility was lower for some of the plasma fatty acids (0.38–0.72), matrix metalloproteinases (0.07–0.91), and premenopausal melatonin (0.44). The ICCs for plasma and urinary phytoestrogens were poor (≤0.09) except for enterolactone (plasma=0.44, urinary=0.52). ICCs for the stress hormones among premenopausal women ranged from 0 (plasma cortisol) to 0.45 (urinary dopamine).

Conclusions: Our results indicate that for the majority of these markers, a single measurement can reliably estimate average levels over a 1–3 year period in epidemiological studies. Where ICCs were fair to good, reproducibility data can be used for measurement error correction. Analytes with poor ICCs should only be used in settings with multiple samples per subject or in populations where ICCs have been shown to be higher.

Impact: This paper summarizes the feasibility of the use of more than 80 biomarkers in epidemiologic studies where only one biospecimen is available to represent longer-term exposure.