Glucose Control, Sulfonylureas, and Insulin Treatment in Elderly People With Type 2 Diabetes and Risk of Severe Hypoglycemia and Death: An Observational Study
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 HbA1c <7% (53 mmol/mol) while on insulin and/or sulphonylurea within 60 days prior to the third HbA1c (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.
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.Conclusions: Elderly subjects with type 2 diabetes and low HbA1c 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.