Lower rate of cardiovascular complications in patients on bolus insulin analogues: a retrospective population-based cohort study

Background: Few studies are available evaluating the impact of rapid-acting insulin analogues on long-term diabetes outcomes. Our aim was to compare the use of rapid-acting insulin analogues versus human regular insulin in relation to the occurrence of diabetic complications in a cohort of diabetic patients through the analysis of administrative databases. Methods: A population-based cohort study was conducted using administrative data from four local health authorities in the Abruzzo Region (900,000 inhabitants). Diabetic patients free of macrovascular disease at baseline and treated either with human regular insulin or rapid-acting insulin analogues were followed for a maximum of 3 years. The incidence of diabetic complications was ascertained by hospital discharge claims. Hazard ratios (HRs) and 95% CIs of any diabetic complication and macrovascular, microvascular and metabolic complications were estimated separately using Cox proportional hazard models adjusted for patients' characteristics and anti-diabetic drug use. Propensity score matching was also used to adjust for significant difference in the baseline characteristics between the two treatment groups. Results: A total of 2,286 patients were included: 914 receiving human regular insulin and 1,372 rapid-acting insulin analogues. During the follow-up, 286 (31.3%) incident events occurred in the human regular insulin group and 235 (17.1%) in the rapid-acting insulin analogue group. After propensity score-based matched-pair analyses, rapid-acting insulin analogues users had a HR of 0.73 (0.58-0.92) for any diabetes-related complication and HRs of 0.73 (0.55-0.93) and 0.55 (0.32-0.96) for macrovascular and metabolic complications respectively, as compared with human regular insulin users. No difference between the two groups was found for microvascular complications. Conclusions: Our findings suggest that the use of rapid-acting insulin analogues is associated with a lower risk of cardiovascular and metabolic complications compared with human regular insulin use.