People with type 2 diabetes who previously used 2 noninsulin antihyperglycemic medications showed no significant association between insulin use and all-cause dementia in a cohort study from British Columbia.
Administrative healthcare data for patients diagnosed with type 2 diabetes in 1998–2016 were examined to identify new users of insulin and new users of a noninsulin class; both groups previously received 2 noninsulin antihyperglycemic classes. Using cause-specific hazards models with death as a competing risk, the estimated hazard ratio [HR] (95% CI) of dementia was as follows: “The analytical comparative cohort included 7,863 insulin versus 25,230 noninsulin users. At baseline, insulin users were more likely to have worse health indicators. A total of 78 dementia events occurred over a median (interquartile range) follow-up of 3.9 (5.9) years among insulin users, and 179 events occurred over 4.6 (4.4) years among noninsulin users. The HR (95% CI) of dementia for insulin use versus noninsulin use was 1.68 (1.29–2.20) before adjustment and 1.39 (1.05–1.86) after multivariable adjustment, which was further attenuated to 1.14 (0.81–1.60) after [inverse probability of treatment weighting].”