AMY1 mutations up type 2 diabetes risk in women with high-carb diets

Intake of dietary carbohydrates interacts with genetic changes in the AMY1 gene to influence the prevalence of type 2 diabetes in adult women, a Korea study has found.

Drawing from the Korean Genome and Epidemiology Study, an ongoing large-scale prospective study, the researchers looked at six variants of AMY1 (rs10881197, rs4244372, rs6696797, rs1566154, rs1930212, and rs1999478) in 4,552 patients, and the potential association with diet, as assessed using a baseline semi-quantitative food frequency questionnaire, as well as with type 2 diabetes.

Over an average follow-up of 12 years, 23.8 percent (n=1,082) of participants developed type 2 diabetes. Analyses of the impacts of genetic variants were stratified by sex and by percentage of energy derived from carbohydrate intake (≤65 percent vs >65 percent).

Cox proportional hazard models showed that among women with >65 percent energy from carbohydrates, the rs6696797 (hazard ratio [HR], 1.28, 95 percent confidence interval (CI), 1.06–1.55), rs4244372 (HR, 1.29, 95 percent CI, 1.07–1.56), and rs10881197 (HR, 1.30, 95 percent CI, 1.08–1.57) variants of AMY1 were significantly correlated with a higher risk of type 2 diabetes. In contrast, the rs1999478, rs1930212, and rs1566154 variants had no effect.

Moreover, none of the genetic variants assessed had any significant impact on type 2 diabetes risk in women who derived ≤65 percent of their energy from carbohydrates. Similarly, all mutations bore no significant risk impact in men regardless of carbohydrate intake.

“The underlying mechanisms linking the genes, diet, and disease remain unclear, but our findings suggest that AMY1 single-nucleotide polymorphisms and dietary factors are both important for type 2 diabetes aetiology,” the researchers said.

“This study provides a sound empirical basis for screening individuals who are minor carriers of AMY1 and have a high-carbohydrate diet, to detect future risk of type 2 diabetes,” they added.