A common diabetes drug, Metformin has been linked to increasing the risk of developing thyroid problems and heart disease. This is not the first diabetic drug to cause problems though. Avandia has been banned in Europe for causing cardiovascular death, but still cleared by the FDA in the US? What! How is it ok for Europeans to be protected from dangerous drugs but not Americans?
Metformin is commonly used to treat type 2 diabetes. It lowers blood sugar levels by reducing glucose production in the liver.
But new research, published in the Canadian Medical Association Journal, found the drug is linked to having an underactive thyroid. This relationship of lowering thyroid hormone is then associated with a host of other ailments including heart disease, goiter, pregnancy problems and even life threatening coma conditions.
The study, published in Canadian Medical Association Journal, examined data on 74,300 patients who received metformin and sulfonylurea, another common diabetes drug, over a 25-year study period.
Of these people, 5,689 were being treated for an underactive thyroid, and 59,937 had normal thyroid function.
In the group with an underactive thyroid, there were 495 incidences of low thyroid-stimulating hormone (TSH) (119.7 per 1000) per year compared with 322 in the normal group (4.5 per 1000).
Dr Laurent Azoulay at the Department of Oncology, McGill University, said: ‘The results of this study confirmed that the use of metformin was associated with an increased risk of low TSH levels in patients with treated hypothyroidism.
‘Given the relatively high incidence of low TSH levels in patients taking metformin, it is imperative that future studies assess the clinical consequences of this effect.’