Poor glycemic control linked to potential risk for heart failure

Improving glycemic control may help prevent heart failure, according to a recent study published in The Lancet. The study enrolled at 20,985 patients with type 1 diabetes to assess variables associated with cardiovascular disease, including age, sex, duration of diabetes, HbA1c, body mass index, systolic and diastolic blood pressure, LDL and HDL cholesterol, and smoking status.

Investigators identified the cohort of patients with type 1 diabetes from the Swedish National Diabetes Registry (NDR). Patients were aged 18 years or older with no known heart failure and were registered between January, 1998, and December, 2003. The patients were followed from their first inclusion in the NDR in 1998 to 2003 until hospital admission with a primary or secondary discharge diagnosis for heart failure, death, or the end of follow-up on Dec. 31, 2009.

The 2 key findings of the study were that 635 (3%) patients needed to be admitted to hospital for heart failure, with an incidence of 3.38 events per 1,000 patient-years. In addition, patients with HbA1c of at least 10.5% had a risk of heart failure 4 times greater than did those with HbA1c less than 6.5%. In their analysis of mean HbA1c as a continuous variable, each 1% increase was associated with a 30% higher risk of heart failure during follow-up, independently of other risk factors for heart failure.

The authors noted that the high incidence of heart failure among study participants, despite the young mean age at inclusion (38.6 years), and the substantially increased risk because of poor glycemic control indicates an independent role of glycemic control in the pathogenesis of heart failure.

“Because treatment for heart failure improves survival and quality of life, clinicians should be observant of signs of heart failure in management of patients with type 1 diabetes, starting at an early stage.”

The study was supported by an unrestricted grant from AstraZeneca, Novo Nordisk Scandinavia, the Swedish Heart and Lung Foundation, and the Swedish Research Council; however supporting organizations had no involvement in protocol design, data collection, data analysis, data interpretation, writing of the report, or the decision to submit the report for publication, the authors stated.