Certain oral diabetes drugs reduce dementia risk in people with type 2 diabetes, American research suggests.

The study followed 559,106 people with type 2 diabetes (mean age 65.7 years) for, on average, 6.8 years. After at least one year of treatment, thiazolidinediones reduced the risk of all-cause dementia by 22 per cent compared with metformin. All-cause dementia risk was 11 per cent lower with metformin plus a thiazolidinedione and 12 per cent higher for sulphonylureas. Thiazolidinediones’ benefit was most marked in overweight or obese patients (28 per cent reduction).

Thiazolidinediones reduced the risk of vascular dementia by 57 per cent and Alzheimer’s disease by 11 per cent. Vascular dementia risk was 14 per cent higher for sulphonylureas. (BMJ Open Diab Res Care 2022;10:e002894)