Association between HbA1c and heart failure in young patients with DM1

January 01, 0001

Association between HbA1c and heart failure in young patients with DM1

Poor glycaemic control is associated with microvascular and macrovascular complications in type 1 diabetes, but whether glycaemic control is associated with heart failure in such patients is not known. The researchers from Sweden aimed to assess this association in a large cohort of patients with type 1 diabetes identified from the Swedish national diabetes registry. They identified all patients (aged greater than or equal to 18 years) with type 1 diabetes and no known heart failure who were registered in the national diabetes registry between January, 1998, and December, 2003. These patients were followed up until hospital admission for heart failure, death, or end of follow-up on Dec 31, 2009.

In a cohort of 20,985 patients with mean age of 38.6 years at baseline, 3% were admitted to hospital with a primary or secondary diagnosis of heart failure during a median follow- up of 9.0 years, with an incidence of 3.38 events per 1000 patient-years. Incidence increased monotonically with HbA1c, with a range of 1.42—5.20 per 1000 patient-years between patients in the lowest (less than 6.5%) and highest (greater than or equal to 10.5%) categories of HbA1c. In a Cox regression analysis, with adjustment for age, sex, duration of diabetes, cardiovascular risk factors, and baseline or intervening acute myocardial infarction and other comorbidities, the hazard ratio for development of heart failure was 3.98 in patients with HbA1c of 10.5% or higher compared with a reference group of patients with HbA1c of less than 6.5%. Risk of heart failure increased with age and duration of diabetes. Other modifiable factors associated with increased risk of heart failure were smoking, high systolic blood pressure, and raised body-mass index. In a subgroup of 18,281 patients (87%) with data for blood lipids, higher HDL cholesterol was associated with lower risk of heart failure, but there was no association with LDL cholesterol.

The researchers concluded: "The positive association between HbA1c and risk of heart failure in fairly young patients with type 1 diabetes indicates a potential for prevention of heart failure with improved glycaemic control."

This is important information and motivation for improved control.

For the full abstract, click here.

The Lancet 378(9786):140-146, 9 July 2011 © 2011 Elsevier Limited
Glycaemic control and incidence of heart failure in 20,985 patients with type 1 diabetes: an observational study. Marcus Lind, Ioannis Bounias, Marita Olsson et al. Correspondence to Marcus Lind: lind.marcus@telia.com

Category: T. Endocrine/Metabolic/Nutritional. Keywords: glycaemic control, incidence, heart failure, type 1 diabetes, observational study, journal watch.
Synopsis edited by Dr Stephen Wilkinson, Melbourne, Australia. Posted on Global Family Doctor 29 July 2011

Pearls are an independent product of the Cochrane primary care group and are meant for educational use and not to guide clinical care.