Patients

We recruited 72 Japanese patients with type 2 diabetes who were hospitalized at Tokyo Medical and Dental University Hospital to receive a diabetes educational program and treatment. Patients with severe renal impairment—defined as those with an estimated glomerular filtration rate (eGFR) of <15 mL/min/1.73 m² or those undergoing renal replacement therapy—and those with a severe infection or serious trauma were excluded. The patients gave written informed consent to participate in this study and for the results of it to be published. Eligible participants (35–83 years old) were those with available data on measured visceral fat area (VFA), whole-body DXA, anthropometric parameters, and laboratory data at baseline and 6 months later. All patients received intensive medical therapy and underwent lifestyle modification, including caloric restriction and regular exercise. The components of the lifestyle guidance varied with the patient according to the plan discussed between the patient, dietician, and physician. Briefly, the patients were instructed to restrict their daily caloric intake to under 25–30 kcal per kg of ideal body weight, and to exercise for 30 min or more at least three times a week. After discharge, the participants continued to receive medical therapy and lifestyle guidance as an outpatient of the hospital. Type 2 diabetes was diagnosed according to the criteria of the Japan Diabetes Society (JDS) [14]. This study protocol was registered as a clinical trial in the University Hospital Medical Information Network (UMIN) system (UMINStudyID: UMIN000024401). The study complied with the principles laid down by the Declaration of Helsinki and was approved by the ethics committee of Tokyo Medical and Dental University (no. M2000-1573).