Long-chain ω6 polyunsaturated fatty acids in erythrocyte phospholipids are associated with insulin resistance in non-obese type 2 diabetics

Abstract

Background Associations have been described between insulin action and long-chain ω6 polyunsaturated fatty acids in skeletal muscle and erythrocytes of healthy individuals. We evaluated whether there was an association between insulin resistance and long-chain ω6 polyunsaturated fatty acids in erythrocyte phospholipids of type 2 diabetics. Methods Erythrocyte phospholipid fatty acid composition was determined in 43 adult non-obese type 2 diabetics. Insulin resistance was estimated by the HOMA mathematical approximations. Individual ω6 fatty acids and the sum of long-chain ω6 polyunsaturated fatty acids were correlated with insulin resistance. The same association was assessed for fatty acid product/precursor ratios taken as measures of Δ5 desaturase, Δ6 desaturase and their combined action. Results Except for 18:2ω6, 20:2ω6 and 20:3ω6, the individual ω6 fatty acids tested and the sum of long-chain ω6 polyunsaturated fatty acids correlated negatively with insulin resistance at p<0.005. Likewise, a negative correlation was found for the combined action of Δ5 and Δ6 desaturases ( p<0.005). Conclusions Our results indicate that formation of long-chain ω6 fatty acids from 18:2ω6 by desaturation–elongation is impaired under insulin resistant conditions and reduced desaturase activities may be involved. In view of our results, we hypothesize that in insulin resistant conditions, insulin-mediated activation of Δ5 and Δ6 desaturases may not occur.