Impact of bodyweight loss on type 2 diabetes remission: a systematic review and meta-regression analysis of randomised controlled trials

Background Bodyweight loss is associated with type 2 diabetes remission; however, the quantitative relationship between the degree of bodyweight loss and the likelihood of remission, after controlling for confounding factors, remains unknown. We aimed to analyse the relationship between the degree of bodyweight loss and diabetes remission after controlling for various confounding factors, and to provide estimates for the effect sizes of these factors on diabetes remission. Methods This systematic review and meta-regression analysis followed Cochrane and PRISMA guidelines to systematically review, synthesise, and report global evidence from randomised controlled trials done in individuals with type 2 diabetes and overweight or obesity. The outcome was the proportion of participants with complete diabetes remission (HbA(1c) <6<middle dot>0% [42 mmol/mol] or fasting plasma glucose [FPG] <100 mg/dL [5<middle dot>6 mmol/L], or both, with no use of glucose-lowering drugs) or partial diabetes remission (HbA(1c) <6<middle dot>5% [48 mmol/mol] or FPG <126 mg/dL [7<middle dot>0 mmol/L], or both, with no use of glucose-lowering drugs) at least 1 year after a bodyweight loss intervention. We searched PubMed, Embase, and trial registries from database inception up to July 30, 2024. Data were extracted from published reports. Meta-analyses and meta-regressions were performed to analyse the data. The study protocol is registered with PROSPERO (CRD42024497878). Findings We identified 22 relevant publications, encompassing 29 outcome measures of complete diabetes remission and 33 outcome measures of partial remission. The pooled mean proportion of participants with complete remission 1 year after the intervention was 0<middle dot>7% (95% CI 0<middle dot>1-4<middle dot>6) in those with bodyweight loss less than 10%, 49<middle dot>6% (40<middle dot>4-58<middle dot>9) in those with bodyweight loss of 20-29%, and 79<middle dot>1% (68<middle dot>6-88<middle dot>1) in those with bodyweight loss of 30% or greater; no studies reported on complete remission with 10-19% bodyweight loss. The pooled mean proportion of participants with partial remission 1 year after the intervention was 5<middle dot>4% (95% CI 2<middle dot>9-8<middle dot>4) in those with bodyweight loss less than 10%, 48<middle dot>4% (36<middle dot>1-60<middle dot>8) in those with 10-19% bodyweight loss, 69<middle dot>3% (55<middle dot>8-81<middle dot>3) in those with bodyweight loss of 20-29%, and 89<middle dot>5% (80<middle dot>0-96<middle dot>6) in those with bodyweight loss of 30% or greater. There was a strong positive association between bodyweight loss and remission. For every 1 percentage point decrease in bodyweight, the probability of reaching complete remission increased by 2<middle dot>17 percentage points (95% CI 1<middle dot>94-2<middle dot>40) and the probability of reaching partial remission increased by 2<middle dot>74 percentage points (2<middle dot>48-3<middle dot>00). No significant or appreciable associations were observed between age, sex, race, diabetes duration, baseline BMI, HbA(1c), insulin use, or type of bodyweight loss intervention and remission. Overall, data were derived from randomised controlled trials with a low risk of bias in all quality domains. Interpretation A robust dose-response relationship between bodyweight loss and diabetes remission was observed, independent of age, diabetes duration, HbA(1c), BMI, and type of intervention.These findings highlight the crucial role of bodyweight loss in managing type 2 diabetes and reducing the risk of diabetes-related complications.