Very Low Blood Sugar Linked to Dementia
Study Raises Concerns About Aggressive Diabetes Treatment in Older Patients
Blood Sugar and Dementia
The study included 16,667 patients with type 2 diabetes enrolled in a northern California diabetes registry. The average age of the patients at study entry was 65.
Whitmer and colleagues examined more than two decades of medical records to determine whether the participants had ever been hospitalized or treated in a hospital emergency department for hypoglycemia.
Symptoms of hypoglycemia can include dizziness, disorientation, fainting, and even seizures. Mild to moderate episodes often don't require treatment, but severe episodes can lead to hospitalization.
None of the study participants had a diagnosis of dementia when they were enrolled in the study in 2003. Four years later, however, 1,822 of the more than 16,600 patients (11%) had been diagnosed with dementia.
Compared to patients with no history of low blood sugar requiring treatment, patients with a single episode of hospital-treated hypoglycemia were found to have a 26% increase in dementia risk.
Patients treated three or more times for hypoglycemia had nearly double the dementia risk of patients who had never been treated.
The study appears in this week's issue of Journal of the American Medical Association.
Aggressive Treatment: Risks vs. Benefits
Alan M. Jacobson, MD, is the director of psychiatric and behavioral research at Harvard Medical School's Joslin Diabetes Center.
He calls the study "compelling" but adds that more research is needed to prove that severe hypoglycemia is a cause of dementia.
"If you believe these findings, that means that just one episode of hypoglycemia can increase risk," he tells WebMD.
The dementia study is just the latest to raise safety concerns about the use of aggressive treatment to achieve tight glucose control in older patients.
Aggressive treatment to achieve blood sugar levels similar to those seen in people without diabetes was linked to an increased risk of death in older patients with type 2 diabetes participating in a large, ongoing clinical trial sponsored by the National Heart Lung and Blood Institute.
Over an average of 3.5 years of treatment, patients in the aggressive treatment arm of the study were 22% more likely to die than patients who were not treated as aggressively.