Reliability of fasting plasma alkylresorcinol concentrations measured 4 months apart

Abstract

Background/Objectives: Alkylresorcinols (ARs) have been suggested as specific dietary biomarkers of whole-grain intake. Evaluation of long-term reliability in repeatedly collected samples in population-based studies is needed to assess whether plasma AR reflect long-term exposure and may be used to study exposure-disease relationships in large-scale epidemiologic studies. The objective of this study was to analyze the reliability (reproducibility) of AR concentrations in fasting plasma measured 4 months apart. Conclusions: Overall, we observed moderate reliability in concentration of total AR and individual homologues over time, although reliability was weaker in men than in women. These findings should be taken into account when using AR as blood biomarkers for whole-grain intake in large-scale epidemiologic studies.

Reliability of fasting plasma alkylresorcinol metabolites concentrations measured 4 months apart

“…10 Higher AR metabolite concentrations observed for men versus women are probably due to higher intact AR concentrations in men, as observed previously among these participants. 4 This may partly be explained by higher intake of AR containing foods or by lower clearance of intact AR among men versus women.…”

“…Men were slightly older, had a higher BMI and a larger waist circumference than women. 4 Geometric mean concentrations of DHBA and DHPPA at baseline were 39.7 nmol/l and 50.6 nmol/l, respectively (Table 1). Higher values were observed for men than for women (Po0.05).…”

“…3 The intraclass correlation coefficient (ICC), defined as the ratio of between-person variance and the sum of between-and within-person variance, is an established indicator of reliability taking both components into account. 3 We previously observed moderate reliability in plasma of total and individual AR concentrations over time (ICC ¼ 0.42), 4 which could be due to the short half-life of AR (B5 h). 5 AR are metabolised in humans via oxidation.…”

“…6 The aim of this study was to assess the reliability (as expressed by the ICC) of concentrations of AR metabolites, DHBA and DHPPA, in human fasting plasma over a 4-month period in a population-based sample, which we previously used to assess the reliability of AR. 4 …”

“…10 Higher AR metabolite concentrations observed for men versus women are probably due to higher intact AR concentrations in men, as observed previously among these participants. 4 This may partly be explained by higher intake of AR containing foods or by lower clearance of intact AR among men versus women.Because of their longer half-lives, DHBA and DHPPA were expected to have higher reliability than intact AR. However, their 4-month reliability was poorer than observed previously for total AR (ICC ¼ 0.42).…”