Marine n-3 fatty acid consumption in a Norwegian renal transplant cohort: Comparison of a food frequency questionnaire with plasma phospholipid marine n-3 levels.

• Main Authors: Joe Chan, My Svensson, Trond Jenssen, Erik B Schmidt, Ivar A Eide
• Format: Article
• Language: English
• Published: Public Library of Science (PLoS) 2020-01-01
• Series: PLoS ONE
• Online Access: https://doi.org/10.1371/journal.pone.0244089
• ISSN: 1932-6203

<h4>Background</h4>High levels of plasma marine n-3 fatty acids (n-3FAs) are associated with improved patient and graft survival in renal transplant recipients (RTRs). The aim of this study was to evaluate the utility of a new food frequency questionnaire (FFQ) to estimate marine n-3FA consumption in future epidemiological research.<h4>Methods</h4>We developed an FFQ with a simple design of 10 questions to assess intake of marine sources of n-3FAs. RTRs included in the recent ORENTRA trial (n = 132) completed the study FFQ at the baseline visit eight weeks after engraftment and at the end of study visit one year post-transplant. We measured the reference biomarker plasma phospholipid (PL) marine n-3FA levels by gas chromatography at the same time points to evaluate association and degree of agreement between FFQ based marine n-3FA consumption estimates and the biomarker.<h4>Results</h4>The median plasma PL marine n-3FA level was 6.0 weight percentage (wt)% (interquartile range [IQR] 4.7 to 7.3) at baseline and 6.3 wt% (IQR 4.8 to 7.4) at end of study. Median FFQ based marine n-3FA consumption estimates were 22.8 g/month (IQR 13.0 to 34.0) at baseline and 20.3 g/month (IQR 14.5 to 32.3) at end of study. FFQ based marine n-3FA consumption estimates showed a moderate correlation with plasma PL marine n-3FA levels at baseline (Spearman's correlation coefficient rs = 0.43, p<0.001) and a stronger correlation at end of study (rs = 0.62, p<0.001). Bland Altman plots showed a reasonable degree of agreement between the two methods at both time points.<h4>Conclusions</h4>Marine n-3FA consumption estimates based on the FFQ showed a moderate correlation with the reference biomarker plasma PL marine n-3FA levels. The FFQ might be useful in epidemiological studies where resources are limited.