Day‐to‐day variability in plasma interleukin‐6 concentrations in healthy adults
Annotatsiya
Chronic inflammation has been associated with chronic disease states such as cardiovascular disease, cancer, and diabetes mellitus. Interleukin‐6 (IL‐6) is a pro‐inflammatory cytokine used as a biomarker to assess inflammation in epidemiological and intervention studies however little is known about the daily variation of this cytokine. The purpose of this study was to evaluate the daily variability of plasma IL‐6 in healthy adults. Fifteen postmenopausal women (aged 50–81) and five men (aged 44–72), all generally healthy, reported for blood draws in a fasted state for three consecutive days for two consecutive weeks. Plasma IL‐6 concentrations were assessed with a commercially purchased ELISA. Results show an average daily IL‐6 concentration of 2.001±1.745 pg/ml (range 0.011–8.951 pg/ml). The mean difference of daily variation within subjects was 0.668±0.687 (range 0.116–3.215). The daily variation represents significant daily fluctuations in IL‐6 concentrations and raises questions regarding the reliability of IL‐6 as a biomarker of inflammation.