Ethnic variations in the risk of hypoglycaemia among people with Type 2 diabetes prescribed insulins and/or sulfonylureas: a historical cohort study using general practice-recorded data.

AIM: To identify ethnic differences in hypoglycaemic risk among people with Type 2 diabetes prescribed insulins and/or sulfonylureas in community settings. METHODS: Using routine general practice-recorded data, two cohorts of adults with Type 2 diabetes from east London were studied between January 2013 and December 2015: (1) adults prescribed insulins ± other antidiabetes medications (n=7269) and (2) adults prescribed sulfonylureas ± other antidiabetes medications excluding insulins (n=12 502). Incidence rate ratios of hypoglycaemia by ethnicity, adjusting for age, sex, socio-economic status and clustering within Clinical Commissioning Groups, were estimated using random effects Poisson regression. RESULTS: Compared with white British people prescribed insulins, those of black Caribbean ethnicity were at increased hypoglycaemic risk [adjusted incidence rate ratio 1.56 (95% CI 1.21,2.01)], while Bangladeshi people had a lower risk [adjusted incidence rate ratio 0.49 (95% CI, 0.38,0.64)]. In the sulfonylurea cohort, black Caribbean, black African and Indian people all had increased risks of hypoglycaemia compared with white British people [adjusted incidence rate ratios 1.63 (95% CI 1.15,2.29), 1.90 (95% CI 1.32,2.75) and 1.93 (95% CI 1.39,2.69), respectively]. CONCLUSION: The differences in hypoglycaemic risk among people with Type 2 diabetes prescribed insulin and/or sulfonylureas warrant further investigation of any differing biological responses and/or cultural attitudes to antidiabetes therapy among ethnic groups, and should be considered by clinicians evaluating the treatment goals of people with Type 2 diabetes using insulins or sulfonylureas.