Effects of hypoglycaemic agents on reducing surrogate metabolic parameters for the prevention of cardiovascular events and death in patients with type 2 diabetes: A systematic review and meta-analysis.

Aims: To investigate the impact of glucose-lowering therapy-induced glycated haemoglobin (HbA1c) reduction on the risk of major clinical events according to body weight change and, as a secondary objective, to evaluate the impact of concomitant reductions in HbA1c and body weight on major clinical events.

Materials And Methods: We searched the MEDLINE and EMBASE databases up to June 30, 2022, for large-scale studies on glucose-lowering therapies in which more than 1000 patient-years of follow-up in each randomized group were completed. The primary outcome was all-cause mortality. The study was registered in PROSPERO (CRD42022355479).

Results: Thirty-four trials involving 227 220 patients with type 2 diabetes were meta-analysed using a random-effects model. Each 1% reduction in HbA1c was associated with a different risk of mortality depending on the ability of glucose-lowering therapies to induce body weight loss or gain. When glucose-lowering therapies were associated with weight gain, the risk of mortality increased by 8% (hazard ratio [HR] 1.08, 95% confidence interval [CI] 1.00-1.16) for each 1% reduction in HbA1c. When glucose-lowering therapies were associated with weight loss, the risk of mortality was reduced by 22% (HR 0.78, 95% CI 0.72-0.85) for each 1% reduction in HbA1c. In addition, concomitant reductions in HbA1c and body weight were associated with a significantly lower risk of mortality and vascular events.

Conclusions: In patients with type 2 diabetes, concomitant reductions in HbA1c and body weight might be more effective in preventing the risk of vascular events and mortality.