Does severe hypoglycaemia influence microvascular complications in Type 1 diabetes? An analysis of the Diabetes Control and Complications Trial database

Abstract

Aims: Severe hypoglycaemia may have a role in aggravating micro- and macrovascular disease in diabetes. Data from the Diabetes Control and Complication Trial have been reanalysed to ascertain whether the frequency of severe hypoglycaemia exerted an influence on the development and progression of retinopathy or nephropathy in people with Type 1 diabetes.

Methods: Using binary longitudinal multiple logistic regression, HbA(1c) at study baseline, mean HbA(1c) throughout the study and the number of severe hypoglycaemic episodes during the trial were compared to examine the risk of development/progression of retinopathy and nephropathy.

Results: Average HbA(1c) during the study and/or HbA(1c) at baseline were independently predictive of retinopathy and nephropathy both in the intensively and the conventionally treated patients (all P ≤ 0.001). However, the number of hypoglycaemic episodes did not add to HbA(1c) in predicting retinopathy [odds ratio (95% CI) 0.99 (0.96-1.01), P = 0.51 in intensively treated patients, 0.94 (0.89-1.00), P = 0.05, conventional] or nephropathy [odds ratio (95% CI) 0.98 (0.95-1.01), P = 0.48 intensive, 1.03 (0.98-1.10), P = 0.17 conventional].

Conclusions: The frequency of exposure to severe hypoglycaemia did not predict a different risk of developing retinopathy or nephropathy in either treatment group of the Diabetes Control and Complications Trial at any given HbA(1c) .