Treatment with insulin or metformin does not appear to reduce levels of inflammatory markers despite improving glucose control in patients with type-2 diabetes, US research shows.
High levels of inflammatory markers, such as high-sensitivity C-reactive protein (hsCRP), have been linked to an increased risk of cardiovascular disease (CVD).
The researchers say that the findings could explain why previous studies have shown no benefit from intensive glucose control on lowering CVD risk among people with diabetes.
The ACCORD trial, published last year, found that although an intensive glucose-lowering regimen significantly reduced a composite outcome of seven diabetes-related events, the effects on cardiovascular events and mortality were not significant.
For this latest study, the researchers examined whether insulin alone or in combination with metformin could lower levels of hsCRP and two other markers, IL-6 and sTNFr2, in 500 patients, aged 18-79, with type-2 diabetes.
Fasting blood samples were collected from the patients after six and then 14 weeks in order to measure inflammatory marker levels.
Overall, the researchers found that neither insulin nor metformin use reduced inflammatory biomarker levels, despite substantially improving glucose control.
The researchers, led by Dr Aruna Pradhan from the Brigham and Women's Hospital in Boston, concluded that 'no consistent association was found between glucose reduction and improvement in inflammatory status'.
The researchers added that the findings highlight the need for patients with diabetes to improve adherence to other therapies that can reduce cardiovascular events, such as exercise, weight management, smoking cessation and statins.