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New study finds sulphonylureas increase cardiovascular risk in diabetes patients



More evidence is emerging that prescribing sulphonylureas to patients with diabetes increases their cardiovascular risk when compared to metformin.

New research shows patients who were initiated with sulphonylurea had a significantly higher incidence of cardiovascular events compared to those initiated with Metformin after two years of follow-up.

It comes after UK research published in the European Heart Journal in April found monotherapy for type 2 diabetes patients with glimepiride, glibenclamide, glipizide or tolbutamide had between a 19% and 32% higher risk of all-cause and cardiovascular death compared with metformin. In patients with a history of heart attacks, this risk was 30%-53% higher.

The latest retrospective cohort study, presented at the American Diabetes Association conference in San Diego this week, analysed data from a cohort of patients aged 65 years old and above with type 2 diabetes who received their first prescription of sulphonylurea or metformin monotherapy between 2003 and 2007 and remained on it for at least 90 days from a medical record database.

Patients also had to have no prescriptions for diabetes drugs or previous cardiovascular events within the prior year and at least two years of follow-up after their first prescription.

Overall, 8,502 patients were included. After controlling for differences in baseline characteristics, patients who initiated with sulphonylurea had a significantly higher incidence of CVD events, at 12.4%, compared with those initiated with metformin after two years of follow-up.

The difference, researchers found, was mainly driven by the increased incidence of ischaemic heart disease, seen in 7.2% of patients with sulphonylurea, compared with 5.5% of patients with metformin.

The likelihood of having a cardiovascular event was 23% higher in patients initiated with sulphonyulrea than with metformin, and sulphonylurea use was associated with a shorter time to first cardiovascular event compared to metformin.

Dr Samuel Engel, associate clinical professor of medicine at the Albert Einstein College of Medicine in New York, concluded: ‘In a cohort of older patients with type 2 diabetes initiating antihyperglycemic therapy, the likelihood of experiencing a cardiovascular event was higher and these events occurred sooner in patients who started with sulphonylurea monotherapy than those who started with metformin.’