Overtreatment of elderly diabetics

The last time I was directly responsible for treating diabetes was fifty years ago, when I was an intern in medicine at UCLA. In my subsequent career as a psychiatrist I was not directly responsible for diabetes care, and as an individual, I don’t have the condition. As a result, I haven’t kept up on diabetes treatment, so a June 11 article on “Diabetes Overtreatment in Elderly Individuals: Risky Business in Need of Better Management” was news to me.

The opening two sentences of the American Diabetes Association’s article on “Tight Diabetes Control” make it sound as if “tight control” should be the goal of treatment:

“Keeping your blood glucose levels as close to normal as possible can be a lifesaver. Tight control can prevent or slow the progress of many complications of diabetes, giving you extra years of healthy, active life.”

In my uninformed state, that’s how I understood how diabetes should be managed, even for over 65ers. But I was wrong.

Several paragraphs later there’s a very clear statement that elderly people with diabetes should be treated differently:

“Elderly people probably should not go on tight control. Hypoglycemia [overly low blood sugar] can cause strokes and heart attacks in older people. Also, the major goal of tight control is to prevent complications many years later. Tight control is most worthwhile for healthy people who can expect to live at least 10 more years.”

The American Geriatrics Society gives precise guidelines for the goal of diabetes treatment in over 65ers. The key measure of diabetes control is hemoglobin A1c. For healthy over 65ers with long life expectancy, the target should be 7.0 – 7.5%. For those with “moderate comorbidity” (so-so health) and a life expectancy of less than 10 years the target should be 7.5 – 8.0%. And with “multiple comorbidities” such as heart failure, cancer, and dementia the goal should be 8.0 – 9.0%.

In 1998, the United Kingdom Prospective Diabetes Study led to widespread belief that “intensive control” – typically meaning a hemoglobin A1c level below 7.0% – was the right target. But that study involved relatively healthy patients with an average age of 53, and over 65ers were excluded. But a study reported 10 years later in which the upper age limit was 79 and the average age of subjects was 63 concluded that “intensive control” produced more harm than benefit for the elderly, resulting in the new guidelines for treatment of over 65ers.

Despite the new guidelines, a recent study of more than 200,000 patients with diabetes who were over 75 and receiving insulin or oral anti-diabetic medication showed how poorly these guidelines are being followed. Fifty percent had hemoglobin A1c levels below 7.0%. In other words – half of this large group were being overtreated!

Why would this happen? The study did not probe the whys and wherefores, but I have two speculations.

First, doctors are notoriously slow to adopt new practices that contradict old ones. To some extent this reflects slow diffusion of information. I may simply not yet have learned about the new findings. But even when doctors are aware of the new perspectives – such as the guidelines promulgated by the American Geriatrics Society – we often continue to follow the familiar course of action.

This conservatism isn’t necessarily a bad thing. The stakes are high in medical treatment. Sometimes the “new certainty” turns out to be wrong. High dose chemotherapy and bone marrow transplantation in breast cancer is a prime example. Thirty thousand women received the highly toxic and sometimes fatal treatment before it was shown to be ineffective. Skepticism about pharmaceutical manufacturer-sponsored research is another reason for conservatism. In my practice, when patients asked about hot-off-the-press medications, unless there was a clear rationale for trying the new approach I typically suggested that we give the new nostrum a year to show its true colors.

My second speculation about the cause of overtreatment is that acknowledging the wisdom of the new guidelines for treatment of the elderly requires acknowledging vulnerability and mortality. We over 65ers are more sensitive to insulin and oral diabetes medications than we were earlier in life. This change puts us at greater risk for injuriously low blood sugar levels. But we, and our physicians, don’t always like to acknowledge greater fragility. Even more so with mortality. If an older patient asks “why should we control my blood sugar levels less rigorously now?” the physician may not feel comfortable saying “tighter control gives benefit in the distant future, and you are not likely to live that long.”

At 90, my late father-in-law was troubled by angina that kept him from walking as far and as briskly as he enjoyed doing. His cardiologist recommended a new surgical procedure. Early in his life my father-in-law had been in the plumbing business, and the surgery made sense to him as “clearing out the pipes.” The results were disastrous. His heart functioned much less well after the surgery. I was impressed with the thoughtfulness and generosity of his response. “My doctors meant well, but they were young men, and they were thinking of younger hearts than mine.”

Jim Sabin, M.D., 75, is an organizer of Over 65, a professor of population medicine and psychiatry at Harvard Medical School, and a Fellow of the Hastings Center. For a previous post on overtreatment, see here.

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