A study from a team of researchers at Yale and the University of California at San Francisco suggests that doctors across the nation are over-treating older diabetes patients to tightly control blood sugar, and that the risks of doing so — low blood sugar episodes resulting from too much insulin — outweigh the benefits.

The study, published in the Journal of the American Medical Association Internal Medicine on Jan. 12, analyzed data collected from 2001 to 2010 from a nationally representative sample of 1,288 elderly patients with diabetes. Researchers divided subjects into three groups: relatively healthy, complex/intermediate health and very complex/poor health based on the patients’ frailty, potential for side effects and other diseases. They found that there was no difference in the proportion of patients achieving tight blood sugar control among the three groups.

“Our hope is to reinforce the message that we are not accounting for important differences in older people and the vulnerabilities they have from aggressive treatment,” said senior author and professor of medicine at UCSF Michael Steinman. “We are putting people at risk and not providing benefit.”

Lead author and Yale professor of medicine Kasia Lipska ’97, said she has seen evidence of the harms of over-treatment through interactions with her patients but has yet to find data supporting the benefits of tight blood sugar control for older adults. She added that older patients who have more compromised health statuses and take several medications are more likely to suffer from complications from treatment, pointing to incidents when her patients experienced sudden episodes of low blood sugar, causing traumatic events like car accidents.

Steinman said over-treatment is driven by performance standards at hospitals incentivizing doctors to reach certain blood sugar goals for their patients.

“Although this was done with good intentions, and some have benefited, it led to lack of individualization of care because we are being asked to treat all patients the same way,” he said. “You feel like you’re being graded on the same level for all patients.”

According to Thomas Donner, professor of medicine at Johns Hopkins University and director of the Johns Hopkins Diabetes Center, tight blood sugar control targets were developed for good reasons — to avoid the complications caused by long-term high blood sugar. He pointed to the fact that decades of elevated glucose levels can lead to eye, kidney and nerve damage, causing blindness in adults and requiring amputations in some instances.

He added that doctors need to constantly re-evaluate treatments for effectiveness and safety.

“As patients become more frail, we should be less aggressive in terms of the targets we shoot for,” he said.

Steinman said he believes the pendulum in diabetes care has swung too far to the side of tight control, noting that more people are hospitalized for diabetes treatment complications than for the disease itself.

According to Lipska, that issue can be fixed through more personalized care and flexibility on the part of physicians, who will need to acknowledge that treatment for a patient will change over the course of his or her lifetime. Patients and physicians need to talk about what treatment makes patients most comfortable, she said.

Steinman said he hopes the study will lead to more education about the risks of over-treatment of older patients.

While Donner agreed with the findings of the study, he noted that retrospective studies merit caution, and researchers have to analyze the data carefully. He said he thinks some doctors are already taking a more personalized approach, but change takes time to spread.

“Therapy needs to be individualized, and the field as a whole is moving in that direction,” he said.

According to the American Diabetes Association, 29.1 million or 9.3 percent of Americans have diabetes. It is the seventh leading cause of death in the nation.