Rochester, MI—Type 2 diabetes patients, especially older people with comorbidities, often are over-treated for type 2 diabetes, raising the risk of hypoglycemia without any real benefit, according to a new Mayo Clinic study.

The report, published online recently by JAMA Internal Medicine, found that more than 25% of adults with type 2 diabetes received intensive glucose-lowering therapy, including 18.7% who were at risk for treatment-related adverse effects because of advanced age and coexisting illnesses.

Clinical guidelines recommend a target glycated hemoglobin (HbA1c) level of less than 7.0% for most nonpregnant adults with type 2 diabetes, although they generally caution that patients with advanced age, a limited life expectancy, and complex health problems will not likely benefit from tight glycemic control and could actually be harmed.

The study examined the association and frequency of intensive glucose-lowering treatment and severe hypoglycemia in 31,542 adults with type 2 diabetes who were not using insulin. Of those, 8,048 patients were treated intensively, including 7,317 patients, 26.5%, with low clinical complexity, and 731 patients, 18.7%, with high clinical complexity. Data was obtained from the OptumLabs Data Warehouse between 2001 and 2013.

Results indicate that intensive treatment of those patients with high clinical complexity—defined as age 75 or older, other specific medical conditions, or both—raised the incidence of severe hypoglycemia from 1.7% to 3%. Severe hypoglycemia can lead to serious injury and even death, according to the report, which points out that intensive treatment for inappropriate patients incurs unnecessary costs with little or no benefit.

“At first, we were surprised to find how much over-testing for HbA1c is occurring among adults of all ages with type 2 diabetes who were already well-controlled,” said lead author Rozalina McCoy, MD, a Mayo Clinic primary care physician and endocrinologist. “But, then, we realized that not only were patients being tested frequently, they were also being treated with more medications than we would expect considering how low their HbA1C already was. So, this led us to do this study—to see how frequently patients are treated so intensively that they may be over-treated and what that does to their risk of hypoglycemia.”

The study defined “intensive treatment” as being treated with more glucose-lowering medications than clinical guidelines consider necessary given a patient’s glycated hemoglobin levels. Specifically, in patients with HbA1c:

• less than 5.6% were considered intensively treated if they were taking any medications;
• 5.7%–6.4% were considered to be intensively treated if using two or more medications at the time of the test, or if started on additional medications after the test, because current guidelines consider those patients to be optimally controlled already.
• 6.5%–6.9% were considered intensively treated if they were taking two or more drugs or insulin.

“Treating patients to very low HbA1c levels is not likely to improve their health, especially not in the short term, but can cause serious harms, such as hypoglycemia,” McCoy added in a Mayo Clinic press release.

Women and nonwhite patients were less likely to be treated intensively, but patients treated by endocrinologists and nephrologists were more likely to be over-treated and, subsequently, to experience severe hypoglycemia, according to the research. In addition, a surprising percentage of high-complexity patients were being treated with sulfonylureas, study authors note, although some guidelines strongly advise against their use in older people.

Results of the research mean “that three out of 100 older or clinically complex patients with diabetes who never had hypoglycemia before, whose HbA1c is within recommended targets, and who are not on insulin, will experience a severe hypoglycemic episode at some point over two years,” emphasized McCoy, who notes that many patients have more mild episodes of hypoglycemia at home which they self-treat.

The study suggests that clinicians individually assess clinical complexity as well as likely risks and benefits of intensive glucose-lowering therapy.

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