Gene variants link to insulin resistance based on diet

(HealthDay)—Variants of insulin receptor substrate 1 (IRS1) are associated with insulin resistance and metabolic syndrome, but only under particular dietary conditions, according to a study published online April 17 in Diabetes Care.

Ju-Sheng Zheng, from Zhejiang University in Hangzhou, China, and colleagues examined two IRS1 variants (rs7578326 and rs2943641) linked to type 2 diabetes and their association with insulin resistance, related traits, and diet in 820 individuals of European ancestry and 844 individuals of Puerto Rican ancestry.

The researchers found a lower risk of insulin resistance, type 2 diabetes, and metabolic syndrome in rs7578326 G-allele carriers and rs2943641 T-allele carriers. In both groups, the risk of metabolic syndrome was lower in rs7578326 G-allele carriers, but only when dietary monounsaturated fatty acids were below the median intake of each group. In the group with European ancestry, the risk of insulin resistance and metabolic syndrome were lower in rs7578326 G-allele carriers and rs2943641 T-allele carriers and their haplotype G-T carriers, but only when the dietary saturated fatty acid-to-carbohydrate ratio was low.

"IRS1 variants are associated with insulin resistance and related traits and are modulated by diet in two populations of different ancestries," Zheng and colleagues conclude.