Harris WS, Luo J, Pottala JV, Margolis KL, Espeland MA, Robinson JG. Red blood cell fatty acids and incident diabetes mellitus in the Women's Health Initiative Memory Study. PLoS One. 2016 Feb 16;11(2):e0147894. doi: 10.1371/journal.pone.0147894. eCollection 2016.
The relations between dietary and/or circulating levels of fatty acids and the development of type 2 diabetes is unclear. Protective associations with the marine omega-3 fatty acids and linoleic acid, and with a marker of fatty acid desaturase activity delta-5 desaturase (D5D ratio) have been reported, as have adverse relations with saturated fatty acids and D6D ratio.
To determine the associations between red blood cell (RBC) fatty acid distributions and incident type 2 diabetes.
Prospective observational cohort study nested in the Women's Health Initiative Memory Study.
Self-reported incident type 2 diabetes.
There were 703 new cases of type 2 diabetes over 11 years of follow up among 6379 postmenopausal women. In the fully adjusted models, baseline RBC D5D ratio was inversely associated with incident type 2 diabetes [Hazard Ratio (HR) 0.88, 95% confidence interval (CI) 0.81-0.95) per 1 SD increase. Similarly, baseline RBC D6D ratio and palmitic acid were directly associated with incident type 2 diabetes (HR 1.14, 95% CI 1.04-1.25; and HR 1.24, 95% CI 1.14-1.35, respectively). None of these relations were materially altered by excluding incident cases in the first two years of follow-up. There were no significant relations with eicosapentaenoic, docosahexaenoic or linoleic acids.
Whether altered fatty acid desaturase activities or palmitic acid levels are causally related to the development of type 2 diabetes cannot be determined from this study, but our findings suggest that proportions of certain fatty acids in RBC membranes are associated with risk for type 2 diabetes.