Plasma variation and reproducibility of oxidized LDL-cholesterol and low-grade inflammation biomarkers among participants of the Malmö Diet and Cancer cohort

Abstract

Context: Large epidemiological studies often collect non-fasting samples, although the reliability of biomarkers may be uncertain.

Objective: To explore the reliability and reproducibility of a single measurement of selected biomarkers in a sub-sample of the Malmö Diet and Cancer cohort.

Methods: We estimated single- and average-measures intraclass correlation coefficients (ICC) for oxidized (ox)-LDL, interleukin (IL)-1β, IL-6, IL-8 and TNF-α.

Results: Single-measures ICC in non-fasting samples of ox-LDL, IL-1β, IL-6, IL-8 and TNF-α were the following: 0.85, 0.71, 0.61, 0.78 and 0.66 for men, and 0.67, 0.81, 0.87, 0.69 and 0.81 for women. Biomarkers at non-fasting and fasting samples were highly correlated (all r > 0.80).

Conclusions: The observed ICC suggest that most of the examined biomarkers (non-fasting blood) would allow meaningful analysis in epidemiological studies.

Keywords:

• Biomarkers of inflammation
• cytokines
• epidemiology
• ICC
• variation

Disclosure statement

The authors declare no conflict of interest.

Funding information

This study was supported by the Cancerfonden (Swedish Cancer Foundation), the Regional Government of Scania, the Påhlsson Research Foundation, the Heart and Lund Foundation, and the Swedish Research Council.