Plasma Alkylresorcinol Metabolite, A Biomarker of Whole-Grain Wheat and Rye Intake, and Risk of Metabolic Syndrome: A Case-Control Study

Background: Whole-grain intake assessed through dietary recording methods has been suggested to be inversely associated with the metabolic syndrome (MetS) risk in several epidemiological studies. However, limited studies have evaluated the association between whole-grain intake and MetS risk when using objective biomarkers of whole-grain intake. The aim of this study was to examine the association between plasma 3-(3,5-dihydroxyphenyl)-1-propanoic acid (DHPPA), a biomarker of whole-grain wheat and rye intake, and MetS risk in a Chinese population.Methods: A case-control study of 667 MetS cases and 667 matched controls was conducted based on baseline data of the Tongji-Ezhou Cohort study. Plasma DHPPA concentrations were assessed by high-performance liquid chromatography-tandem mass spectrometry. MetS was determined using definition of the Joint Interim Statement.Results: Plasma DHPPA was inversely associated with MetS risk. After adjustment for age, sex, body mass index, smoking status, alcohol drinking status, physical activity and education level, the odds ratios (ORs) for MetS across increasing quartiles of plasma DHPPA concentrations were 1 (referent), 0.86 (0.58-1.26), 0.77 (0.52-1.15), and 0.59 (0.39-0.89), respectively. The inverse relation between plasma DHPPA and MetS persisted in stratified analyses according to confounding factors. In addition, the cubic spline analysis revealed a potential nonlinear association between plasma DHPPA and MetS, with a steep reduction in the risk at the lower range of plasma DHPPA concentration.Conclusions: Our study revealed that higher plasma DHPPA concentrations were associated with lower odds of MetS. Our findings provided further evidence to support health benefits of whole grain consumption.