Intra-individual Variation of Plasma Adipokine Levels and Utility of Single Measurement of These Biomarkers in Population-Based Studies

Abstract

Adipokines, soluble mediators produced by adipocytes, may link adipose tissue to the inflammatory, metabolic, and immune dysregulation that characterize many obesity-related diseases. The stability of plasma adipokine levels within individuals, their seasonal variability, intercorrelations, and relationships to wellestablished measures of adiposity are incompletely defined. We measured levels of 12 adipokines [interleukin 1B (IL-1B), IL-6, IL-8, tumor necrosis factor-A (TNF-A), plasminogen activator inhibitor-1 (PAI-1), high-sensitivity C-reactive protein (hsCRP), monocyte chemoattractant protein-1 (MCP-1), nerve growth factor (NGF), leptin, adiponectin, hepatocyte growth factor (HGF), and resistin] in four seasonal random plasma samples of 48 male participants of a population-based cohort study. The representativeness of single measurements was assessed by correlating the adipokine levels of a single, random sample with the mean levels from the remaining three samples using a bootstrap approach and using intra-class correlation coefficients (ICC). Spearman correlations between adipokine levels, age, body mass index (BMI), and waist-to-hip ratio (WHR) were estimated. Correlations between plasma adipokine levels from one random sample and the mean of the remaining three seasonal samples ranged from 0.57 to 0.89. Over the 1-year study period, the ICCs for adipokine levels ranged from 0.44 (PAI-1) to 0.83 (HGF). IL-8, MCP-1, and resistin levels were positively associated with age; HGF and PAI-1 levels were correlated with BMI and WHR. This study suggests that adipokine levels in a single blood sample may be useful biomarkers of inflammation in population-based studies of obesity-related disease. (Cancer Epidemiol Biomarkers Prev 2007;16(11):2464 -70)

Dietary factors associated with plasma high molecular weight and total adiponectin levels in apparently healthy women

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Pre‐diagnostic blood immune markers, incidence and progression of B‐cell lymphoma and multiple myeloma: Univariate and functionally informed multivariate analyses

“…However, several studies have provided evidence of a reasonable between‐to‐within person variability ratio (ICC) suggesting temporal stability for panels of cytokines 30, 31, 32, 33, 34, 35. Finally, blood cytokines are produced not only by those cell types considered to play pivotal roles in the immune system and in inflammatory responses, including lymphocytes, monocytes and mast cells but also by macrophages and, for some cytokines, also fibroblasts, neutrophils and endothelial cells.…”

Leptin and Soluble Leptin Receptor in Risk of Colorectal Cancer in the European Prospective Investigation into Cancer and Nutrition Cohort

“…In this analysis, the interassay CVs for leptin were 4.5% for low (mean, 5.3 ng/mL); 7.9% for medium (mean, 11.0 ng/mL); and 5.9% for high levels (mean, 26.1 ng/mL); for sOB-R the respective CVs were 10.0% (mean, 10.9 ng/mL); 9.7% (mean, 11.0 ng/mL); and 9.4% (mean, 27.2 ng/mL). In reproducibility studies reported intraclass correlation coefficients for leptin were 0.74, over 4 years in the Health Professionals Follow-up Study (33), 0.83, over 1 year in the Janus cohort study (10), 0.84 over 4 seasons in MONICA and V€ asterbotten Intervention Study (34), and for sOB-R, 0.82 over 3 years in the Nurses' Health Study (35).…”