title: Effect of Metformin on mortality in patients with heart failure and type 2 diabetes mellitus.
abstract: Type 2 diabetes mellitus (DM) plus chronic heart failure (CHF) is a common but lethal combination and therapeutic options are limited. Metformin is perceived as being relatively contraindicated in this context, although mounting evidence indicates that it may be beneficial. This study was carried out to investigate the use of metformin therapy for treating patients with DM and CHF in a large population-based cohort study. The Health Informatics Centre-dispensed prescribing database for the population of Tayside, Scotland (population ∼400,000) was linked to the Diabetes Audit and Research in Tayside Scotland (DARTS) information system. Patients with DM and incident CHF from 1994 to 2003 receiving oral hypoglycemic agents but not insulin were identified. Cox regression was used to assess differences in all-cause mortality rates between patients prescribed metformin and patients prescribed sulfonylureas with adjustment for co-morbidities and other therapies. Four hundred twenty-two study subjects (mean ± SD 75.4 ± 0.5 years of age, 46.2% women) were identified: metformin monotherapy (n = 68, mean age 75.5 ± 1.1 years, 48.5% women), sulfonylurea monotherapy (n = 217, mean age 76.7 ± 0.7 years, 45.2% women), and combination (n = 137, mean age, 73.4 ± 0.7 years, 46.7% women). Fewer deaths occurred in metformin users, alone or in combination with sulfonylureas, compared to the sulfonylurea monotherapy cohort at 1 year (0.59, 95% confidence interval 0.36 to 0.96) and over long-term follow up (0.67, 95% confidence interval 0.51 to 0.88). In conclusion, this large observational data suggest that metformin may be beneficial in patients with CHF and DM. These findings need to be verified by a prospective clinical trial.
authors.affiliation: Department of Nursing and Midwifery, University of Stirling, Stirling, United Kingdom.
authors.forename: Josie M M
authors.initials: JM
authors.lastname: Evans
authors.forename: Alex S F
authors.initials: AS
authors.lastname: Doney
authors.forename: Matlooba A
authors.initials: MA
authors.lastname: AlZadjali
authors.forename: Simon A
authors.initials: SA
authors.lastname: Ogston
authors.forename: John R
authors.initials: JR
authors.lastname: Petrie
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Morris
authors.forename: Allan D
authors.initials: AD
authors.lastname: Struthers
authors.forename: Aaron K F
authors.initials: AK
authors.lastname: Wong
authors.forename: Chim C
authors.initials: CC
authors.lastname: Lang
mesh_terms: D000368:Aged; D048909:Diabetes Complications / Q000188:drug therapy / Q000401:mortality*; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy*; D005260:Female; D006333:Heart Failure / Q000188:drug therapy / Q000401:mortality*; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D008297:Male; D008687:Metformin / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D007004:Hypoglycemic Agents; D008687:Metformin