Study finds why type 2 diabetes increases risk of fractures in older women

• People with type 2 diabetes are at risk of a number of complications, and this includes increased risk of fractures through falls.
• Research into why has proved inconclusive as people with type 2 diabetes tend to have higher bone density.
• A group of researchers from Sweden have shown that type 2 diabetes reduces physical function in older women, which could explain the higher rate of fractures in this group.

While women with type 2 diabetes are more likely to experience fractures, this is due to overall poorer physical health that makes them more likely to fall, not lower bone density.

Previous research into the bone structure of people with type 2 diabetes has been inconclusive, and studies have suggested that bone density in this population is higher but the structure of it is weaker.

Now, a group of researchers from Sweden have shown that women ages 75–80 with type 2 diabetes had poorer physical function and ability, including having slower movement and being less strong, than women who did not have diabetes.

Lead author Mattias Lorentzon, MD, professor in geriatric medicine at the Institute of Medicine, Gothenburg University, and Chief Physician at the Osteoporosis Clinic at the Sahlgrenska University Hospital, Mölndal, Sweden told Medical News Today in an email: “Previous studies have not had access to comprehensive and detailed data on bone characteristics and physical function, making it difficult to determine which of these factors is most important for the increased risk of fractures .

“Our study clearly shows that older women with type 2 diabetes have much worse physical function but no different or better bone characteristics, indicating that the increased fracture risk is due to falls as a result of poor physical function.”

The results are published in the journal JAMA Network Open .

Testing bone density and balance with type 2 diabetes

To investigate the role of bone density in bone fractures in women aged 75-80 with type 2 diabetes, researchers analyzed data on 294 individuals with type 2 diabetes and 2714 women without diabetes from the Sahlgrenska University Hospital Prospective Evaluation of Risk of Bone Fractures study cohort, which was recruited through the Swedish National Registry.

Data included height and weight, as well as medical history, including fractures, smoking, family history of fractures, medication, diabetes, rheumatoid arthritis , and alcohol use.

Further data was collected on physical activity, bone density, and bone quality. Women with type 2 diabetes had a higher BMI on average, as expected, and were found to have a lower prevalence of reported osteoporosis medication use compared with controls.

Researchers found women with type 2 diabetes had 4.4% higher bone density in the hip and similar increases were seen in the femoral neck and lumbar spine compared with controls. There was a slightly lower bone density found in other parts of the spine.

Participants with type 2 diabetes had a 19.2% lower Physical Activity Scale for the Elderly score than those without diabetes.

More specifically, on a balance test in which they had to stand on one leg, they could stand for a 27.2% shorter period than those without diabetes. In a test designed to test the function of the lower half of the body, it took participants with diabetes 13.9% longer to rise from a standard armchair, walk to a marker 3m away, turn, walk back, and sit down again. They also had 9.9% slower walking speed, 17.3% fewer rises on the 30-second chair stand test, and 9.7% lower grip strength.

How diabetes medications affect bone health

Type 2 diabetes is a chronic medical condition caused by your body losing its ability to make enough insulin, or use it properly, which results in blood sugar that is too high. It is strongly linked to obesity, and can result in problems with nerve damage and problems with blood vessels which can lead to cardiovascular disease , kidney disease, neuropathy, blindness, and lower-extremity amputation.

Treatment for type 2 diabetes is often oral medication such as metformin , or increasingly glucagon-like peptide 1 (GLP-1) agonists, which also treat obesity.

In the current study, researchers observed that women taking medication for type 2 diabetes had higher bone density, greater bone strength, and better bone microarchitecture, but poorer physical performance than controls.

There was a 71% increased fracture risk in women treated with insulin, compared with controls, for any fracture, and women with oral type 2 diabetes treatment had a 27% risk higher risk of any fracture.

“Our study clearly shows that older women with type 2 diabetes have much worse physical function but no different or better bone characteristics, indicating that the increased fracture risk is due to falls as a result of poor physical function,” explained Lorentzon.

Why does diabetes increase the risk of fractures?

Yoshua Quinones, M.D. and Internist with Medical Offices of Manhattan who was not involved in the research told Medical News Today : “Type 2 diabetes often leads to an increased bone density but also a higher risk of fractures. This happens because, despite denser bones, the quality of the bone is lower due to factors like high blood sugar levels and inflammation.

“People with type 2 diabetes are more likely to have fractures because their bones are denser and weaker. High blood sugar levels and inflammation may damage bones, and diabetes can also affect balance and vision, leading to more falls,” he explained.

Increased risk of fractures comes with an increased risk of pain and disability and poorer quality of life, which ultimately results in lower mobility, which can have an impact on overall health as well as resulting in a loss of independence.

Lorentzon explained that one way of tackling this is to improve the physical function that this study showed could be lost due to type 2 diabetes.

“We are interested in investigating if improving physical function can reduce the fracture risk in these patients,” he said.