Diabetes in Elderly can Increase Risk for Dementia

Studies show that diabetes in older patients not only increase their risk of hypoglycemia, but can raise their risk of dementia.

Kristine Yaffe, MD, of the University of California San Francisco and colleagues studied older diabetic patients who'd had an episode of hypoglycemia, many of which developed dementia several years later.

"Our results provide evidence for a bidirectional association between severe hypoglycemia and dementia," they wrote, according to the study. "Hypoglycemia may impair cognitive health, and reduced cognitive function may increase the risk for a hypoglycemic event that could further compromise cognition, resulting in a detrimental cycle."

Though the association between hypoglycemia and cognitive impairment has been long-debated, some work has suggested that it may be reciprocal.

Yaffe and colleagues analyzed data from 3,075-patient Health, Aging and Body Composition Study. This information showed that a quarter of the patients had diabetes but no cognitive impairement was noted.

Mean patient age was 74, 47 percent of patients were African American, and 47.6 percent were female. Patients were followed for a mean of 12 years, according to the study.

During the 12 year follow-up period, 61 patients, or approximately 7.8 percent, reported a hypoglycemic event, and 18.9 percent of participants developed dementia. In fact, the study shows that significantly more patients who had a hypoglycemic event developed dementia than those who did not.

Yaffe and colleagues explained that hypoglycemia may contribute to the pathogenesis of dementia through several mechanisms, including the fact that recurrent severe hypoglycemia has been shown

However, researchers also point out that determining whether dementia is linked to hypoglycemia in some cases can be risky. For instance, cognitive dysfunction may be delayed by unrecognized symptoms of hypoglycemia, the study notes.

The information for this study can be found online in JAMA Internal Medicine.