Lower incidence of macrovascular complications in patients on insulin glargine versus those on basal human insulins: A population-based cohort study in Italy

OBJECTIVE. To compare the use of insulin glargine and intermediate/long-acting human insulin (HI) in relation to the first occurrence of diabetes-related complications in a cohort of diabetic patients. RESEARCH AND METHOD DESIGN. A population-based cohort study was conducted using administrative data from four local health authorities in the Abruzzo Region (900,000 inhabitants). A record linkage-analysis was done to identify diabetic patients free of macrovascular disease at baseline and consistently treated with insulin glargine or intermediate/long-acting HIs during a 3-year follow-up. Patients were followed from January 1, 2006 until the date of hospital admission for any diabetes-related complications, censoring (death or emigration), or December 31, 2008, whichever occurred first. Hazard ratios (HRs) and 95% confidence intervals (CIs) of any diabetic complication and macrovascular, microvascular and metabolic complications were estimated separately using Cox proportional hazard models adjusted for age, gender, previous microvascular or metabolic complications, concomitant drugs (i.e. low-dose aspirin, antihypertensive drugs, antiarrhythmic drugs and lipid-lowering agents) and anti-diabetic drugs use in quartiles. RESULTS. Totally, 1,921 diabetic patients were included: 744 intermediate/long-acting HI users and 1,177 insulin glargine users. After adjustment for covariates, insulin glargine users had a HR (95% CI) of 0.58 (0.45-0.74) for any diabetes-related complication and HRs of 0.63 (0.47-0.86), 0.55 (0.32-0.96) and 0.38 (0.19-0.73) for macrovascular, microvascular and metabolic complications, respectively, as compared with intermediate/long-acting HI users. CONCLUSIONS. Our findings suggest that the use of insulin glargine is associated with a lower risk of diabetic complications compared with traditional basal insulins.