Long-acting insulin analogues and diabetic retinopathy: a retrospective cohort study.

PURPOSE

Long-acting insulin analogues were developed to facilitate consistent glycemic control without excessive hypoglycemia. However, structural modifications of the insulin molecule can alter biological responses and binding characteristics with specific receptors. The aim of this study was to estimate the risk of sight-threatening diabetic retinopathy (STDR) associated with treatment using long-acting insulin analogues compared with intermediate-acting insulin in patients with type 2 diabetes mellitus (T2DM).

METHODS

A retrospective cohort consisting of patients with T2DM aged 20 years of age and older with newly initiated treatment with long-acting insulin analogues (glargine and detemir) and intermediate-acting human insulin was identified from the National Health Insurance database between January 2004 and December 2006 and was subdivided into different cohorts. The risk of the development of STDR was determined by Cox regression models and compared between different cohorts.

FINDINGS

Of the 46,739 eligible patients, initiators of insulin glargine, insulin detemir, and neutral protamine Hagedorn (NPH) insulin were identified for comparison using propensity-score matching methods. Long-acting insulin analogues were not associated with changed risk for STDR by intention-to-treat and time-varying use approaches between either matched or unmatched cohorts.

IMPLICATIONS

The strategies that aim at preventing diabetic retinopathy by treating T2DM patients with long-acting insulin analogues remain further prospective studies with longer follow-up period to validate our observations within an appropriate dosage range and to further evaluate the safety of long-acting insulin analogues on reducing the progression of diabetic retinopathy.