Relationship between deterioration of glycated hemoglobin-lowering effects in dipeptidyl peptidase-4 inhibitor monotherapy and dietary habits: Retrospective analysis of Japanese individuals with type 2 diabetes

The present study was designed to assess possible relationships between deterioration of the glycated hemoglobin (HbA1c)-lowering effects in dipeptidyl peptidase-4 inhibitor (DPP4i) monotherapy and macronutrient intake among individuals with type 2 diabetes. Type 2 diabetes patients who began and continued DPP4i monotherapy without any prescription change for 1 year were retrospectively stratified into two groups: (i) patients who maintained their HbA1c levels during the 0.5- to 1-year period after DPP4i initiation (group A, ΔHbA1c [1–0.5 year] <0.4%, n = 53); and (ii) those whose HbA1c levels increased [group B, ΔHbA1c (1–0.5 year] ≥0.4%, n = 10). Group B had significantly higher ΔHbA1c (1–0.5 year), Δbodyweight (1–0.5 year) and fat intake, especially of saturated and monounsaturated fats; the carbohydrate and protein intake were similar between groups. Multiple regression analyses showed that fat intake, especially saturated fat intake, was significantly correlated with ΔHbA1c (1–0.5 year). Thus, dietary habits, especially saturated fat intake, might well contribute to deterioration of the HbA1c-lowering effects in DPP4i monotherapy.