A nationwide, retrospective, case-control study of older adults in Denmark suggests that the bisphosphonate alendronate that is widely used to treat osteoporosis may protect against new-onset type 2 diabetes. But these preliminary findings need to be confirmed in a randomized controlled trial, experts said.
The registry study showed that from 2008 to 2018, among individuals in Denmark age 50 and older (with a mean age of 67), those who were taking alendronate were 36% less likely to have new-onset type 2 diabetes than age- and sex-matched individuals who were not taking the drug, after controlling for multiple risk factors.
The results also suggest that longer alendronate use and higher compliance might be more protective.
Rikke Viggers, MD, a PhD student in the department of clinical medicine, Aalborg (Denmark) University, presented the findings during an oral session at the annual meeting of the European Association for the Study of Diabetes.
“Excitingly, our research suggests that alendronate, an inexpensive medicine widely used to treat osteoporosis, may also protect against type 2 diabetes,” Dr. Viggers summarized in a press release issued by the EASD.
“Type 2 diabetes is a serious lifelong condition that can lead to other serious health issues such as stroke, heart disease, blindness, and limb amputation,” she noted, “and anything that prevents or even delays it will also reduce a person’s risk of all these other conditions.”
“We believe that doctors should consider this when prescribing osteoporosis drugs to those with prediabetes or at high risk of type 2 diabetes,” she added.
Preliminary results, need for RCT
However, these are preliminary results, Dr. Viggers cautioned during the oral presentation and in an email. “This is a registry-based study,” she stressed, “and we cannot conclude causality.”
“We do not know if this effect [of decreased risk of developing diabetes among people taking alendronate] is ‘real’ and what the mechanisms are.”
“It could be a direct effect on peripheral tissues, for example, muscle and adipose tissue,” Dr. Viggers speculated, “or an indirect effect through bone metabolites that may impact glucose metabolism.”
The group is now conducting a randomized controlled trial in patients with diabetes and osteopenia or osteoporosis to examine the relationship between alendronate and insulin sensitivity, bone indices, and glycemic control.
They also aim to investigate whether alendronate is the optimal antiosteoporotic therapy for patients with type 2 diabetes. Preliminary results suggest that other bisphosphonates have similar effects.
“Alendronate decreases bone turnover and may not be beneficial in healthy bones,” Dr. Viggers noted. “However, as far as I know, potential other side effects have not been tested in healthy bones,” so further research is needed.
Dr. Charles Vega
Invited to comment, Charles P. Vega, MD, who presented a case and a crowd-sourced opinion about deprescribing bisphosphonates, noted that type 2 diabetes is most often diagnosed between age 40 and 60, although a few cases are diagnosed after age 65, and the study by Dr. Viggers and colleagues suggests that alendronate might help lower the risk of diabetes onset in these older adults.
“This is an interesting retrospective analysis,” said Dr. Vega, health sciences clinical professor, family medicine, University of California, Irvine, but like the study authors, he cautioned that “it should be verified with other data.”
“A meta-analysis from clinical trials of bisphosphonates which followed blood glucose levels would be helpful,” he said.