Association Between Type 2 Diabetes and All-Cause Hospitalization and Mortality in the UK General Heart Failure Population

OBJECTIVES This study sought to investigate in the general heart failure (HF) population, whether the associations between type 2 diabetes (T2D) and risk of hospitalization and death, are modified by changing glycemic or drug treatment intensity. BACKGROUND In the general HF population, T2D confers a higher risk of poor outcomes, but whether this risk is modified by the diabetes status is unknown. METHODS A nested case-control study in an incident HF database cohort (2002 to 2014) compared patients with T2D with those without for risk of all-cause first hospitalization and death. T2D was stratified by categories of glycosylated hemoglobin (HbA1c) or drug treatments measured 6 months before hospitalization and 1 year before death and compared with the HF group without T2D. RESULTS In HF, T2D was associated with risk of first hospitalization (adjusted odds ratio [aOR]: 1.29; 95% confidence interval [CI]: 1.24 to 1.34) and mortality (aOR: 1.24; 95% CI: 1.29 to 1.40). Stratification of T2D by HbA1c levels, compared with the reference HF group without T2D, showed U-shaped associations with both outcomes. Highest risk categories were HbA1c > 9.5% (hospitalization, aOR: 1.75; 95% CI: 1.52 to 2.02; mortality, aOR: 1.30; 95% CI: 1.24 to 1.47) and < 5.5% (hospitalization, aOR: 1.42; 95% CI: 1.12 to 1.80; mortality, aOR: 1.29; 95% CI: 1.10 to 1.51, respectively). T2D group with change in HbA1c of > 1% decrease was associated with hospitalization (aOR: 1.33; 95% CI: 1.18 to 1.49) and mortality (aOR: 1.36; 95% CI: 1.24 to 1.48). T2D drug group associations with hospitalization were no medication (aOR: 1.12; 95% CI: 1.04 to 1.19), oral antihyperglycemic only (aOR: 1.34; 95% CI: 1.27 to 1.41), oral antihyperglycemicthorninsulin (aOR: 1.36; 95% CI: 1.21 to 1.52), and insulin only (aOR: 1.61; 95% CI: 1.43 to 1.81); and with mortality for the same drug groups were 1.31 (95% CI: 1.23 to 1.39), 1.16 (95% CI: 1.11 to 1.22), 1.19 (95% CI: 1.06 to 1.34), and 1.43 (95% CI: 1.31 to 1.57), respectively. The T2D group with reduced drug treatments were associated with hospitalization (aOR: 2.13; 95% CI: 1.68 to 2.69) and mortality (aOR: 2.09; 95% CI: 1.81 to 2.41). CONCLUSIONS In the general HF population, T2D stratified by glycemic control and drug treatments showed differential risk associations. Routine measures of dynamic diabetes status provide important prognostic indication of poor outcomes in HF. Crown Copyright (C) 2018 Published by Elsevier on behalf of the American College of Cardiology Foundation. All rights reserved.