The anti-diabetic drug pioglitazone, usually prescribed to patients with Type 2 diabetes, may be linked to a heightened risk of bladder cancer, according to a team of Canada-based researchers.

Intake of the drug has the potential to increase bladder cancer risk by 63 percent. The drug is primarily taken to control the blood sugar levels of diabetic patients.

The study compared pioglitazone with rosiglitazone, an alternative drug taken by diabetic patients.

Both these drugs fall under the larger thiazolidinedione drug class. However, the study didn't find a startling connection for rosiglitazone with bladder cancer, as in the case of pioglitazone. Both these drugs were approved by the Food and Drug Administration (FDA) in 1999.

The study further highlighted the link that the duration of usage of pioglitazone had with bladder cancer risk. A longer period of usage meant higher risks.

"The results of this large population-based study indicate that pioglitazone is associated with an increased risk of bladder cancer," affirmed lead author Dr. Laurent Azoulay of the Centre for Clinical Epidemiology, Lady Davis Institute at the Jewish General Hospital in Canada.

Researchers studied almost 146,000 English people from a database, the United Kingdom Clinical Practice Research Datalink (CPRD). It looked into individuals who had undergone treatment with anti-diabetic drugs during the period of Jan. 1, 2000 to July 31, 2013.

These participants continued to be analyzed as part of this extended study, up until July 31, 2014. It was observed that over the period of four years and seven months, 622 of the participants had been diagnosed with bladder cancer.

The findings of the study is published in the journal The BMJ on March 30. The results suggest that doctors and patients alike must carefully assess the overall risks and benefits of medications.