Carbohydrate Intake Interacts With SNP276G>T Polymorphism in the Adiponectin Gene to Affect Fasting Blood Glucose, HbA1C, and HDL Cholesterol in Korean Patients With Type 2 Diabetes

Background/Objective: The SNP276G>T polymorphism in the adiponectin gene has been reported to be associated with type 2 diabetes and impaired glucose tolerance. The objective of this study was to examine whether SNP276G>T polymorphism influences the blood glucose levels in relation to dietary carbohydrate intake. Subjects/Methods: In an ongoing, prospective study, 673 patients with type 2 diabetes (339 men and 334 women, aged 40-85years) were recruited from one of two diabetes clinics in Seoul, Korea. The levels of carbohydrate intake were categorized as <55%, 55%-65%, and >65% of total energy intake. Results: Significant gene-nutrient interactions between SNP276G>T polymorphism and the level of carbohydrate intake were found, which modulated plasma fasting blood glucose (p = 0.0277), HbA1C (p = 0.0407), and high-density lipoprotein (HDL) cholesterol (p = 0.0134) concentrations. The G allele was associated with higher fasting blood glucose only in subjects consuming a low-carbohydrate diet (<55% of energy). However, when carbohydrate intake was intermediate (55%-65%), carriers of the T allele had greater fasting blood glucose and HbA1C concentrations. When carbohydrate intake was high (>65%), carriers of the T allele had greater HDL cholesterol concentrations. This interaction was significant even when carbohydrate intake was considered a continuous variable (p = 0.0200 for fasting blood glucose, p = 0.0408 for HbA1C, and p = 0.0254 for HDL cholesterol), suggesting a strong dose-response relation. Conclusions: Our data show that the effect of the SNP276G>T polymorphism on plasma fasting blood glucose, HbA1C, and HDL cholesterol concentrations depends on dietary carbohydrate intake.