Patients treated with type-2 diabetes drug metformin live longer than those without the disease, a new study has found.

The research involved 180,000 people and was conducted by scientists at the Cardiff University.

Metformin is already known to lower cancer risk. The researchers in the current study wanted to know if the drug can help lower the risk of early death in diabetics.

People with type-2 diabetes can't use the hormone insulin to control blood sugar levels. Metformin is either used alone or with other medication to regulate glucose levels in these people. Previous research has shown that the drug increases lifespan in mice models.

For the present study, the researchers compared the life expectancy in diabetes patients treated with metformin with that of patients on another anti-diabetes drug - sulphonylurea.

The team also compared life expectancy of diabetics with age and gender-matched non-diabetics.

The data for the study came from the UK Clinical Practice Research Datalink, which represented around 10 percent of the UK population. The researchers identified 78,241 patients who were on metformin and 12,222 patients who were prescribed sulphonylurea.

"Patients treated with metformin had a small but statistically significant improvement in survival compared with the cohort of non-diabetics, whereas those treated with sulphonylureas had a consistently reduced survival compared with non-diabetic patients. This was true even without any clever statistical manipulation," said Craig Currie from Cardiff University's School of Medicine, according to a news release. 

The researchers said that metformin not only reduces cancer and heart problem risk, but can also lower pre-diabetics' risk of developing diabetes.

The research, however, doesn't mean that people with diabetes will have healthy, long life. According to Currie, diabetics usually have to switch over to more aggressive treatments to control their condition. On an average, a diabetes diagnosis results in a loss of eight years of life. The researchers recommend that people eat healthy and stay active to minimize risk of developing chronic health conditions.

The study is published in the journal Diabetes, Obesity and Metabolism.