Participants
T2D
TYPE 1 DIABETES, CHRONIC RENAL FAILURE
Eligible patients were T2D outpatients with ordinary physical activity, aged 65–80 years with HbA1c levels of 7.4–10.4% (the percentage value of the National Glycohemoglobin Standardization Program) who were under non-pharmacological (diet and exercise) or pharmacological treatment with oral anti-diabetic drugs, and whose HbA1c levels were stable (within 0.1% in absolute value) in the past two months. Patients were ineligible if they had type 1 diabetes; were treated with DPP4 inhibitors, GLP-1 receptor agonists, or insulin; or if they had chronic renal failure (estimated glomerular filtration ratio [eGFR] < 30 mL/min/1.73 mEligible patients were anonymously reported to the registration office at the Department of Preventive Medicine, Kyushu University Graduate School of Medical Sciences (Fukuoka, Japan) and then randomly allocated to either sitagliptin treatment or not. Allocation was conducted according to the sequence of a randomization list, which was prepared a priori via the permuted block method with a block size of 10 containing equal assignments to the two arms. Patients with sitagliptin treatment (sitagliptin group) were administered sitagliptin 50 mg once daily. A reduced dose (sitagliptin 25 mg once a day) was administered to patients with an eGFR of 30–60 mL/min/1.73 m