Incidence and predictors of remission and relapse of type 2 diabetes mellitus in Japan: Analysis of a nationwide patient registry (JDDM73)

To determine the incidence of remission and 1-year relapse from remission and associated factors in patients with type 2 diabetes.A total of 48 320 Japanese patients with type 2 diabetes aged ≥18 years, with glycated haemoglobin (HbA1c) levels ≥48 mmol/mol (6.5%) and/or glucose-lowering drug prescription, were identified from databases of specialist clinics from 1989 and followed until September 2022. Remission was defined as HbA1c <48 mmol/mol at least 3 months after cessation of a glucose-lowering drug. Relapse was defined as failure to maintain remission for 1 year. Factors associated with remission and relapse were evaluated by logistic regression analysis.The overall incidence of remissions per 1000 person-years was 10.5, and for those with HbA1c levels of 48 to 53 mmol/mol (6.5% to 6.9%), those taking no glucose-lowering drugs at baseline, and those with a ≥10% body mass index (BMI) reduction in 1 year, it was 27.8, 21.7 and 48.2, respectively. Shorter duration, lower baseline HbA1c, higher baseline BMI, higher BMI reduction at 1 year, and no glucose-lowering drugs at baseline were significantly associated with remission. Among 3677 persons with remission, approximately two-thirds (2490) relapsed within 1 year. Longer duration, lower BMI at baseline, and lower BMI reduction at 1 year were significantly associated with relapse.The results showed that the incidence of remission and predictors of relapse, especially baseline BMI, might differ greatly between East Asian and Western populations. Furthermore, the relationships of BMI reduction with remission and relapse may be greater in East Asian than in Western populations, implying ethnic differences in returning from overt hyperglycaemia to nearly normal glucose levels.