Long-Term Sulfonylurea Use and Impaired Awareness of Hypoglycemia Among Patients With Type 2 Diabetes in Taiwan

PURPOSE We undertook a study to investigate the relationship between duration of medication use and prevalence of impaired awareness of hypoglycemia (IAH) among patients with insulin-treated or sulfonylurea-treated type 2 diabetes in Taiwan. METHODS A total of 898 patients (41.0% insulin users, 65.1% sulfonylurea users; mean [SD] age = 59.9 [12.3] years, 50.7% female) were enrolled in pharmacies, clinics, and health bureaus of Tainan City, Taiwan. Presence of IAH was determined with Chinese versions of the Gold questionnaire (Gold-TW) and Clarke questionnaire (Clarke-TW). Sociodemographics, disease and treatment histories, diabetes-related medical care, and health status were collected. We used multiple logistic regression models to assess the relationship between duration of medication use and IAH. RESULTS Overall IAH prevalence was 41.0% (Gold-TW) and 28.2% (Clarke-TW) among insulin users, and 65.3% (Gold-TW) and 51.3% (Clarke-TW) among sulfonylurea users. Prevalence increased with the duration of sulfonylurea use, whereas it decreased with the duration of insulin use. After controlling for potential confounders, 5 or more years of sulfonylurea use was significantly associated with 3.50-fold (95% CI, 2.39-5.13) and 3.06-fold (95% CI, 2.11-4.44) increases in the odds of IAH based on the Gold-TW and Clarke-TW criteria, respectively. On the other hand, regular blood glucose testing and retinal examinations were associated with reduced odds in both insulin users and sulfonylurea users. CONCLUSIONS The prevalence of IAH was high among patients using sulfonylureas long term, but the odds of this complication were attenuated for those who received regular diabetes-related medical care. Our study suggests that long-term sulfonylurea use and irregular follow-up increase risk for IAH. Further prospective studies are needed to confirm the observed associations.