Research carried out at the University of East Anglia reveals that as many as one in every 50 patients taking the drugs Avandia (rosiglitazone) and Actos (pioglitazone) over a period of 26 months will have to be hospitalized for heart failure, The Guardian reported Friday.

The researchers said that the class of drugs doubles the risk of heart failure, and even those with no history of heart problems are affected.

"This means that the diabetes drugs could have caused thousands of additional cases of heart failure," Yoon Loke, a clinical pharmacologist who led the research, was quoted as saying.

Loke and his American colleagues pooled data from 78,000 patients who have taken the drugs, some of them during the manufacturers' trials, and also looked closely at the cases of 200 people who suffered heart failure and found they were not people who were obviously at risk.

"Most patients in the studies did not have heart failure prior to starting on treatment with these drugs. There doesn't seem to be a group of patients who are safe from these side-effects," Loke said.

Concerns about the safety of the drug were triggered in May when a leading US cardiologist published evidence of a link to heart attacks and death, whose study was strongly contested by the manufacturers in the New England Journal of Medicine.

The evidence from the new research in UK will add urgency to a special meeting of the US regulator, the Food and Drug Administration (FDA) which was already scheduled for Monday to discuss the safety of the drugs, the report said.

Avandia is made by the British company GlaxoSmithKline and Actos by Takeda.