EASD: Poor Glucose Control in Diabetics Predicts Heart Failure

Dr. Marcus Lind(University of Gothenburg, Uddevalla, Sweden) presented the results of the study at the European Association for the Study of Diabetes (EASD) 2011 Meeting. As he noted in his presentation, heart failure is 2.5 times more common in diabetic patients than in the general population, but much of the focus of glucose-lowering has been on ischemic heart disease effects despite the rising numbers of HF patients with diabetes and healthcare costs associated with HF care. Moreover, previous trials and meta-analyses looking at the impact of glucose control on heart-failure diagnoses have been inconsistent, potentially due to low patient numbers.

For their study, they linked data on patients from the Swedish National Diabetes Register with national hospital discharge and mortality registries, using a primary end point of hospitalization for a primary or secondary diagnosis of heart failure. In all, more than 83 000 patients who had type 2 diabetes but no HF were registered between 1998 and 2003 then followed for a median of 7.2 years.

As Lind showed, more than 13% of the study cohort was hospitalized for heart failure over study follow-up, but risk of hospitalization varied based on levels of HbA_1c. In analyses that adjusted for a wide range of coronary and diabetes risk factors and use of cardiovascular drugs, an HbA_1c level of 10% or greater was associated with more than a twofold risk of HF hospitalization, as compared with patients with a HbA_1c level <6%. Patients with HbA_1c levels in the range of 6% to 7% or 7% to 8%, however, were not statistically more likely than patients with levels <6% to develop HF.

Overall, for every one-percentage-unit increase in HbA_1c (10.9-mmol/mol increase), risk of heart failure increased by 12%. Male gender, older age, and longer duration of diabetes increased the risk of HF.

During the question-and-answer session following Lind's presentation, Dr. Naveed Sattar (University of Glasgow, Scotland) asked whether increased use of statins over the study period may in part explain the rising numbers of HF diagnoses: by keeping people with coronary disease alive longer, healthcare providers are allowing them to "go on to get HF," Sattar suggested. Lind, however, said that he and his colleagues controlled as much as possible for markers of coronary disease and concluded that this likely does not explain the findings.

European Association for the Study of Diabetes (EASD) 47th Annual Meeting: Abstract 77.