title: Predictors of insulin initiation in metformin and sulfonylurea users in primary care practices: the role of kidney function.
abstract: The aims were to investigate predictors of insulin initiation in new users of metformin or sulfonylureas in primary care practices, in particular, its association with decreased renal function. Data from 9103 new metformin and 1120 sulfonylurea users with normal baseline glomerular filtration rate (eGFR) >90 ml/min/1.73 m(2) from 1072 practices were retrospectively analyzed (Disease Analyzer Germany: 01/2003-06/2012). Cox regression models and propensity score matching was used to adjust for confounders (age, sex, practice characteristics, comorbidity). Insulin treatment was started in 394 (4.3%) metformin and in 162 (14.5%) sulfonylurea users within 6 years (P < .001). Kaplan-Meier curves (propensity score matched patients) showed that the metformin group was at a lower risk of insulin initiation compared to sulfonylurea users throughout the study period. A substantial eGFR decline (category: 15-<30 ml/min/1.73 m(2)) was significantly associated with a higher likelihood to have insulin initiated (adjusted hazard ratio [HR]: 2.39; 95% CI: 1.09-5.23) in metformin but not in sulfonylurea (HR: 0.45; 95% CI: 0.16-1.30) users. New users of sulfonylurea monotherapy in primary care practices in Germany were about 3-fold more likely to start insulin therapy than those with metformin. Kidney function decline was associated with earlier insulin initiation in metformin but not in sulfonylurea users.
authors.affiliation: IMS HEALTH, Frankfurt, Germany kkostev@de.imshealth.com.
authors.forename: Karel
authors.initials: K
authors.lastname: Kostev
authors.affiliation: Department of Internal Medicine, Neurology and Dermatology, University of Leipzig, Germany.
authors.forename: Franz-Werner
authors.initials: FW
authors.lastname: Dippel
authors.affiliation: Institute of Biometrics and Epidemiology, German Diabetes Center, Düsseldorf, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Rathmann
mesh_terms: D000328:Adult; D000368:Aged; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D007328:Insulin / Q000627:therapeutic use*; D007677:Kidney Function Tests; D008297:Male; D008687:Metformin / Q000627:therapeutic use*; D008875:Middle Aged; D011320:Primary Health Care / Q000706:statistics & numerical data; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D013453:Sulfonylurea Compounds / Q000627:therapeutic use*
chemical_list: D007004:Hypoglycemic Agents; D007328:Insulin; D013453:Sulfonylurea Compounds; D008687:Metformin
keywords: insulin initiation; kidney function; metformin; sulfonylurea; type 2 diabetes