CVD risk rises in line with HbA1c in Type 2 diabetes
MedWire News: Study findings from the Swedish National Diabetes Register show that the risk for cardiovascular disease (CVD) in people with Type 2 diabetes increases progressively with increasing glycated hemoglobin (HbA1c) levels.
"Previous epidemiological studies have shown a positive association between HbA1c and CVD risk, although large randomized clinical trials in Type 2 diabetic patients have not been able to show that intensive treatment and lowering of HbA1c are beneficial with regard to CVD risk," explain Katarina Eeg-Olofsson (University of Gothenburg, Sweden) and colleagues.
To investigate further, they carried out an observational study of 18,334 Type 2 diabetes patients, aged 30-79 years, and with a baseline HbA1c ranging from 5.0-10.9%. The participants were recruited in 1997-1998 and followed up until 2003.
For each 1% increase in baseline or updated HbA1c, relative risks for fatal or nonfatal coronary heart disease (CHD), CVD (CHD or stroke), and total mortality increased by a significant 11-13%, 10-11%, and 9-10%, respectively.
The authors found that patients with a mean baseline HbA1c of 6.5% had a 20% and 16% lower risk for CHD and CVD, respectively, than those with an average baseline HbA1c of 7.5%.
Previous studies have indicated that intensive glucose control, with a target HbA1c below 7%, may not be beneficial for patients with long-standing diabetes or previous CVD.
"By contrast, in the present study we found progressively increasing risks of fatal/nonfatal CVD, fatal CVD, and total mortality with higher HbA1c levels in subgroups of patients with shorter (mean 3 years) or longer disease duration (mean 15 years), and in subgroups with or without previous CVD," writes the team.
"Our findings support current treatment guidelines, underlining risk benefits in patients who achieve the treatment target HbA1c <7% compared to those with 1% higher mean HbA1c," the researchers conclude in the Journal of Internal Medicine.
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By Helen Albert