Aided by medications such as insulin, the tight blood-sugar control might reflect an overtreatment of diabetes, according to a recent study.
By Jill Daly /
Older people with diabetes are often told about the importance of keeping their blood sugar levels under control to prevent long-term complications, like cardiovascular disease or kidney damage. But studies are showing that some are actually controlling their disease too tightly, which is raising additional health risks.
Success in keeping blood sugar levels steady is measured by the HgA1c blood test, known as A1C. The normal range is about 4 percent to 6 percent.
“Studies show that tight control is not for everyone,” said Patricia Bononi, medical director of the Joslin Diabetes Center affiliates at Allegheny Health Network. “Treatment should be individualized.”
A recent study reviewing data from older adults with diabetes, divided into three groups depending on how many other health conditions they had, found that some people striving for the lower range of A1C numbers, under 7 percent, might have had higher rates of experiencing low blood sugar. Symptoms range from sweating and dizziness to confusion and slurred speech and can lead to coma and death.
Aided by medications such as insulin and sulfonylurea medicines (including glyburide), the tight blood-sugar control might reflect an overtreatment of their diabetes, according to the study in the Jan. 12 online edition of JAMA Internal Medicine.
A 2011 study reported high rates of death among high-risk patients with Type 2 diabetes who were in a program that kept their average blood sugar levels at what is considered ultra-tight: below 6 percent. After at least three years, the rate of death among people with tight control was 19 percent higher than the group of patients getting the standard therapy, with A1C targets of 7 percent to 7.9 percent.
Most recently, in the Jan. 15 online edition of Diabetes Care, a review of care for 15,880 veterans 65 years old and up with diabetes and dementia found that many were at a high risk of hypoglycemia. Of the tightly controlled patients, 75 percent used sulfonylureas or insulin or both. Lead author was Carolyn T. Thorpe, assistant professor in the University of Pittsburgh School of Pharmacy.
As people get older, Dr. Bononi said, they should periodically reassess their treatment and talk to their doctor to determine their target blood sugar and A1C levels. For example, the longer people have diabetes, the harder it becomes to recognize the signs of low blood sugar.
“If you do have problems recognizing low blood sugar, the A1C should not be super tight,“ she said. “They might not be eating as much, or feeling ill and not taking their medicine.”
Dr. Bononi said it’s not surprising that the people in the recent study who had the most health problems also had high rates of low blood sugar.
“The sickest people were on dialysis and had a lot of things going on… [blood sugar is] harder to manage. There may be other things going on that caused them to have hypoglycemia. Dialysis patients don’t always have counter-mechanisms [to regulate blood sugar].”
Even in the middle group, she said, multiple conditions with different medicines make it hard to determine if there was overtreatment.
The challenge of managing diabetes is really too much for an elderly patient and the family doctor alone, said Linda Siminerio, executive director of the Diabetes Institute at the University of Pittsburgh.
She’s a long-time advocate of team-based care. On Jan. 5 she was named new chair of the National Diabetes Education Program, a joint program of the National Institutes of Health and the Centers for Disease Control and Prevention. It shares resources for professionals and patients on its website, ndep.nih.gov.
Ms. Siminerio said individual assessments are often not being done.
“For seniors, their eating habits change, their activity level changes … their lives change. Sometimes your social situation changes, your spouse dies,” she said, adding that a spouse can notice behavior that indicates low blood sugar. Older people with diabetes are at a higher risk for cognitive problems, too, which also might make it harder to manage their glucose monitoring.
“That’s why we need resources,” Ms. Siminerio said, “working with a dietitian when there are nutrition changes. Or maybe it’s someone who really can’t manage … a pharmacist or diabetes educator need to be involved. It’s a lot of work.”
A specialist’s point of view
As a geriatrician, David Nace said for about 10 years his field has recognized the need for individualized goals for glucose control, that people 65 and over are not all the same.
He is the director of long-term care programs in the division of geriatric medicine at Pitt and chief of medical affairs for UPMC Senior Communities.
Many of his elderly patients who have diabetes eventually need insulin and sulfonylureas, which he called a “notorious group of medicines.”
“Some have a particularly long half-life, that take longer to clear the kidney system,” he explained, resulting in higher levels of the drug remaining in the body. And, because of age-related changes, the body uses the drugs differently, he said.
Signs of hypoglycemia may be harder to detect, he said. “Older adults tend to be on a lot of medicine, certain ones might mask the symptoms.”
Dr. Bononi’s primary advice to avoid hypoglycemia remains the same: “1. check your glucose regularly and 2. have some fast-acting glucose with you so if you have a low glucose level, you can treat it quickly.”
This season, with many patients hospitalized with the flu, Dr. Bononi said it’s particularly important for sick elderly people with diabetes to check their glucose level. “Sometimes every couple of hours, if they are getting high levels or low levels. If they can’t take their pills, that may be time to seek medical advice. Or if they can’t eat and blood sugars are so low that it might be they need intravenous glucose. … It’s not an easy disease.”