REUTERS HEALTH: People with type 1 diabetes are more likely to break a bone when their average blood sugar levels are dangerously high, a large study suggests.
Researchers examined data on more than 47,000 people with diabetes, including 3,329 with type 1, the less common form, which typically develops in childhood or young adulthood when the pancreas can't produce insulin. The rest had type 2 diabetes, which is linked to obesity and aging and happens when the body can't properly use or make enough insulin to convert blood sugar into energy.
All of these patients were diagnosed with diabetes in the UK between 1995 and 2015. During the study period, 672 people with type 1 diabetes and 8,859 with type 2 diabetes experienced bone fractures.
For type 1 diabetics, the risk of fracture was 39 per cent higher when their average blood sugar levels over time were dangerously high than it was with lower blood sugar levels, the study found. Moderately high average blood sugar didn't appear to impact the risk of fracture for these patients, however.
"In patients with type 1 diabetes, it is important to have good glycemic control, for almost everything and also to prevent fractures," said Dr. Francesc Formiga of Barcelona University.
Blood sugar levels didn't appear to influence the risk of fractures for patients with type 2 diabetes.
Despite this, patients with both types of diabetes should make every effort to keep their blood sugar in a healthy range, Formiga, who wasn't involved in the study, said by email.
"People with high levels of sugar should be aware that it is not good for their global health or for their bones and may increase the risk of fractures, therefore they should modify their treatment, according to the recommendations of their doctors," Formiga said.
Diabetes has long been linked to an increased risk of fractures, but research to date has been mixed regarding exactly what role blood sugar levels play in this risk, Dr. Christian Meier of University Hospital Basel in Switzerland and colleagues write in the Journal of Clinical Endocrinology and Metabolism.
Several complications of diabetes may contribute to an increased risk of falls and fractures including cognitive impairment; nerve damage (neuropathy) that diminishes sensation in the feet and other extremities; and retinopathy, or eye damage that makes it harder to detect obstacles that might cause a fall.
Among type 1 diabetes patients in the study, people with vascular complications like retinopathy were 29 percent more likely to experience fractures than people who didn't have these complications. Vascular complications didn't appear to influence fracture risk for people with type 2 diabetes.
With type 1 diabetes, kidney failure was also associated with more than doubled odds of a fracture, the study found.
The study wasn't designed to prove whether or how elevated blood sugar might impact the risk of falls or fractures in people with diabetes.
One limitation of the study is that researchers didn't account for whether patients had diabetic neuropathy, said Dr. James Richardson, a professor in physical medicine in rehabilitation at Michigan Medicine in Ann Arbor who wasn't involved in the research.
That factor might explain a lot of the accidents leading to bone fractures, he said.
"Fall risk is markedly increased in people who cannot successfully respond to a postural perturbation (such as a trip or slip, ankle turn) in the roughly 400 milliseconds available to do so," Richardson said by email.
"This requires rapid and precise information that 'reports' the perturbation," Richardson said. "This comes, primarily, from precise sensation in the feet and ankles and excellent visual acuity."