The study finds that among a group of more than 8,000 women aged 75 and over, those taking statins had a 33 percent higher chance of being diagnosed with new-onset diabetes.
Lead author Dr. Mark Jones, of the UQ School of Public Health, says that statins are highly prescribed for this age group, but there are few clinical trials studying how they affect older women. "The vast majority of research is on 40- to 70-year-old men," he notes.
Statins are a class of drug designed to lower blood cholesterol, most of which is made in the liver.
They reduce liver production of cholesterol and also help the liver to remove cholesterol from the blood.
While the body needs cholesterol, if there is too much of it in the blood it can lead to buildup of plaque in the walls of arteries, which is a risk factor for stroke and heart disease - the leading cause of death for men and women in the United States.
The women were free of diabetes at the start of 2003, and the team assessed statin exposure based on prescriptions dispensed between 2002 and 2013.
Over the 10 years of follow-up, the team found that 49 percent of the women had filled prescriptions for statins and 5 percent had begun treatment for new-onset diabetes.
Statistical analysis revealed that statin exposure was linked to a 33 percent higher risk of developing diabetes. The risk increased with dose of statin - up to 51 percent for the highest dose.
Dr. Jones says that he and his team were most concerned to find this dose-response effect between statin use and risk of diabetes, especially as, "over the 10 years of the study most of the women progressed to higher doses of statins."
He concludes that doctors and their elderly female patients should be aware of these findings, and urges:
"Those elderly women taking statins should be carefully and regularly monitored for increased blood glucose to ensure early detection and management of diabetes."