Biomarkers of food intake and nutrient status are associated with glucose tolerance status and development of Type 2 diabetes

BACKGROUND Diet is frequently associated with both the development and prevention of type 2 diabetes (T2D) but there are a lack of objective tools for assessing the causal relationships between diet and T2D. Biomarkers of dietary intake could help strengthen the link between a healthy diet and prevention of diabetes. <br/><br/> OBJECTIVE The objective of this study was to explore how diet is related to glucose tolerance status (GTS) and future development of T2D irrespective of metabolic syndrome (MetS) risk factors, using dietary biomarkers as an objective measure of dietary intake unconfounded by recall and reporting bias. RESEARCH DESIGN AND METHODS Dietary biomarkers were measured in plasma from 64-year old women with different glucose tolerance classifications (normal glucose tolerance; NGT (n=190), impaired glucose tolerance; IGT (n=209), and diabetes (n=230)), randomly selected from the population register in Gothenburg, Sweden. The same subjects were followed up after 5 years to determine changes in glucose tolerance (NGT (n=167), IGT (n=174) and diabetes (n=159)). Analysis of covariance (ANCOVA) adjusted for significant measures of MetS was used to explore baseline data for associations between dietary biomarkers, GTS and new T2D cases at follow up (n=69). RESULTS After adjustment for MetS risk factors, alpha-tocopherol, alkylresorcinols C17 and C19 (markers of whole grain wheat and rye), b-alanine (meat), eicosapentaenoic acid (fish) and linoleic acid were associated with GTS and 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid (CMPF) (fish) and alpha-tocopherol with future development of T2D. <br/><br/> CONCLUSIONS Several dietary biomarkers were strongly associated with GTS irrespective of MetS factors, underlining the role of diet in development and prevention of T2D. The use of multiple dietary biomarkers can provide a link with diet that is unencumbered by recall bias normally associated with dietary studies and allows examination of the role of diet even when dietary information is not available