Researchers at the Children’s Hospital of Philadelphia (CHOP) have linked the presence of diabetes in Friedreich’s ataxia (FA) patients to more severe symptoms and a reduced capacity to manage daily living tasks.
These insights suggest that identifying patients with diabetes and more actively managing their disease might help improve their health and function.
Their study, “Impact of diabetes in the Friedreich ataxia clinical outcome measures study,” appeared in the journal Annals of Clinical and Translational Neurology. It followed 811 FA patients who were part of a study exploring the natural history of the disease.
Diabetes is common in FA, and more so in older and non-ambulatory patients, earlier studies have found. Those with longer repeats of the GAA mutation in the frataxin gene, which causes FA, also face a higher risk of developing the disease.
Along with researchers at the Perelman School of Medicine at the University of Pennsylvania, the team analyzed data from FA patients and found diabetes in 6.4 percent of all participants (and specifically 3 percent of children and 9 percent of adults). These numbers were based on participants’ self-reports of a diabetes diagnosis.
Also in this group, the team noted that those with diabetes tended to be older and have longer GAA repeats in the least affected gene copy.
Among them, 48 percent were treated with insulin alone, and 17 percent used both insulin and an oral treatment. In addition, 23 percent reported using only oral medications, and 12 percent reported having diabetes without taking any blood sugar-lowering drugs.
FA patients with diabetes had more severe disease, measured by the Friedreich’s Ataxia Rating Scale, and more disability. They also performed worse on several functional tests, such as the 9-Hole Peg Test of hand and arm function, a mobility and leg function test called the Timed 25-Foot Walk, and vision tests.
FA patients diabetes lost certain functions earlier in life. An advanced statistical analysis also showed that diabetes mediated a small proportion of the effect of longer mutation stretches on poor outcomes. Researchers urged further studies to gather evidence to support screening for diabetes or developing new treatment standards for this patient group.