Abstract
Aims: Controversy exists regarding the importance of glycaemic control in patients with type 2 diabetes mellitus (T2DM) and chronic heart failure (CHF) based on conflicting reports using single baseline HbA1c. Using time-weighted mean of serial HbA1c measures has been found to be a better predictor of diabetic complications as it reflects the glycaemic burden for that individual over time. We therefore sought to confirm this in a large cohort of patients with T2DM and incident CHF.
Methods: A time-weighted mean HbA1c was calculated using all HbA1c measures following CHF diagnosis. Patients were grouped into five categories of HbA1c (≤6.0%, 6.1-7.0%, 7.1-8.0%, 8.1-9.0 and >9.0%). The relationship between time-weighted mean HbA1c and all-cause deaths after CHF diagnosis was assessed.
Results: 1,447 patients with T2DM met study criteria. During a median follow up of 2.8 years, there were 826 (57.1%) deaths with a crude death rate of 155 deaths per 1000 person-years (95% CI, 144-166). Cox regression model, adjusted for all significant predictors, with the middle HbA1c category (7.1-8.0%) as the reference, showed a U-shaped relationship between HbA1c and outcome [ HR(95% CI)]: HbA1c<6.0 %: HR(95%CI) 2.5(1.8-3.4);
HbA1c 6.1-7.0%: HR(95%CI) 1.4(1.1-1.7); HbA1c 8.1-9.0%: HR(95%CI) 1.3(1.0-1.6) and HbA1c>9.0%: HR(95%CI) 1.8(1.4-2.3). Further analysis revealed a protective effect of insulin sensitizers (ie. metformin) [HR (95%CI) 0.75(0.61-0.93)] but not other drug classes.
Conclusions: In patients with T2DM and CHF, our study shows a U-shaped relationship between HbA1c and mortality with the lowest risk in patients with modest glycaemic control (HbA1c=7.1-8.0%) and those treated with insulin sensitizes.
| Original language | English |
|---|---|
| Pages (from-to) | 94-102 |
| Number of pages | 9 |
| Journal | European Journal of Heart Failure |
| Volume | 18 |
| Issue number | 1 |
| Early online date | 13 Dec 2015 |
| DOIs | |
| Publication status | Published - Jan 2016 |
Keywords
- Chronic heart failure outcomes
- Diabetes
- Time-weighted HbA1c
- Metformin
Access to Document
- Final Published Version
© 2015 The Authors. European Journal of Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
