Survival as a function of HbA(1c) in people with type 2 diabetes: a retrospective cohort study.

Background: Results of intervention studies in patients with type 2 diabetes have led to concerns about the safety of aiming for normal blood glucose concentrations. We assessed survival as a function of HbA(1c) in people with type 2 diabetes.

Methods: Two cohorts of patients aged 50 years and older with type 2 diabetes were generated from the UK General Practice Research Database from November 1986 to November 2008.