Glucose Control, Sulfonylureas, and Insulin Treatment in Elderly People With Type 2 Diabetes and Risk of Severe Hypoglycemia and Death: An Observational Study

Objective: To estimate the relative and absolute risk of severe hypoglycemia and mortality associated with glucose control, sulphonylurea and insulin treatment in elderly people with type 2 diabetes. <p>Research Design and Methods: We identified elderly subjects (≥70 years) with type 2 diabetes between 2000 and 2017 in the UK CPRD primary care database with linkage to hospitalization and death data. Subjects with three consecutive HbA_1c <7% (53 mmol/mol) while on insulin and/or sulphonylurea within 60 days prior to the third HbA_1c (exposed) were matched to not exposed. Hazard ratios (HRs) and absolute risks were estimated for hospitalizations for severe hypoglycemia and cardiovascular and non-cardiovascular-related mortality. </p> <p>Results: Among 22,857 included subjects (6288 [27.5%] exposed, of which 5659 [90.0%] on sulphonylurea), 10,878 (47.6%) deaths and 1392 (6.1%) severe hypoglycemic episodes occurred during the follow-up. Compared to non-exposed, the adjusted HR in exposed was 2.52 (95% CI: 2.23, 2.84) for severe hypoglycemia; 0.98 (0.91, 1.06) for cardiovascular mortality; and 1.05 (0.99, 1.11) for non-cardiovascular mortality. In a 70-, 75-, 80- and 85-year-old subject, the 10-year risk of severe hypoglycemia was 7.7%, 8.1%, 8.6%, and 8.4% higher than non-exposed while differences for non-cardiovascular mortality ranged from 1.2% (-0.1, 2.5) in a 70-year-old to 1.6% (-0.2, 3.4) in an 85-year-old subject. Sulphonylurea and insulin were more relevant predictors of severe hypoglycemia and death than glucose levels.</p> Conclusions: Elderly subjects with type 2 diabetes and low HbA_1c on sulphonylurea or insulin treatment experienced a substantially higher risk of hospitalization for severe hypoglycemia but had no clear evidence of increased risks of mortality.