Is it this one?
Common diabetes drug metformin could cause thyroid and heart problems, experts warn
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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).
In patients with a treated underactive thyroid, metformin was associated with a 55 per cent increased risk of low TSH levels compared with treatment with sulfonylurea.
Metformin therapy did not appear to affect people with normal thyroid function.
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.' '
http://www.dailymail.co.uk/health/a...rt-disease-thyroid-problems-experts-warn.html