Background Biomarker variability, which includes within-individual variability (CVI), between-individual variability (CVG) and methodological variability (CVP + A) is an important determinant of our ability to detect biomarker-disease associations. Estimates of CVI and CVG may be population specific and little data exists on biomarker variability in diverse Hispanic populations. Hence, we evaluated all 3 components of biomarker variability in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) using repeat blood collections (n = 58) and duplicate blood measurements (n = 761–929 depending on the biomarker). Methods We estimated the index of individuality (II) ((CVI + CVP + A) / CVG) for 41 analytes and evaluated differences in the II across sexes and age groups. Results Biomarkers such as fasting glucose, triglycerides and ferritin had substantially higher inter-individual variability and lower II in HCHS/SOL as compared to the published literature. We also found significant sex-specific differences in the II for neutrophil count, platelet count, hemoglobin, % eosinophils and fasting glucose. The II for fasting insulin, post oral glucose tolerance test glucose and cystatin C was significantly higher among the 18–44 y age group as compared to the 45 + y age group. Conclusions The implications of these findings for determining biomarker-disease associations in Hispanic populations need to be evaluated in future studies.
Bibliographical noteFunding Information:
The Hispanic Community Health Study/Study of Latinos was supported by contracts from the National Heart, Lung, and Blood Institute to the University of North Carolina, University of Miami, Albert Einstein College of Medicine, Northwestern University and San Diego State University. The following Institutes/Centers/Offices contribute to the HCHS/SOL through a transfer of funds to the NHLBI: National Center on Minority Health and Health Disparities, the National Institute of Deafness and Other Communications Disorders, the National Institute of Dental and Craniofacial Research, the National Institute of Diabetes and Digestive and Kidney Diseases, the National Institute of Neurological Disorders and Stroke, and the Office of Dietary Supplements.
- Analytical variation
- Biomarker variability