Reproducibility of Metabolomic Profiles among Men and Women in 2 Large Cohort Studies

Abstract

Background Rigorous studies are necessary to demonstrate suitability of metabolomics platforms to profile metabolites in archived plasma within epidemiologic studies of human disease, for which attenuation of effect estimates due to measurement error is a key concern. Methods Using a liquid chromatography-tandem mass spectrometry platform, we quantified 257 metabolites from archived plasma to evaluate metabolite inter-assay reproducibility, reproducibility with delayed processing, and within-person reproducibility over time. Inter-assay reproducibility was assessed with coefficients of variation (CVs) from 60 duplicate plasma samples donated by Nurses’ Health Study and Health Professionals Follow-up Study participants, and 20 quality control pool plasma replicates. Metabolite reproducibility over a 24- to 48-hour processing delay (n=48 samples) and within-person reproducibility over 1-2 years (n=80 samples) were assessed using Spearman and intraclass correlation coefficients (ICCs). Results CVs were <20% for 92% of metabolites and generally were similar by plasma anticoagulant type (Heparin or EDTA) and fasting time. Approximately 75% of metabolites were reproducible over delays in processing of blood specimens (Spearman correlation or ICC ≥0.75, comparing immediate and 24-hour delayed processing). Carbohydrates and purine/pyrimidine derivatives were most adversely affected by the processing delay. Ninety percent of metabolites were reproducible over 1-2 years within individuals (Spearman correlation or ICC ≥0.4). Conclusions For potential use in epidemiologic studies, the majority of plasma metabolites had low CVs and were reproducible over a 24-hour processing delay and within individuals over 1-2 years. Certain metabolites, such as carbohydrates and purine/pyrimidine derivatives, may be challenging to evaluate if samples have delayed processing.

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