Strict Blood Sugar Control Not Always Best
For some with diabetes, intensive therapy may have pluses and minuses
(HealthDay News) --
Tight blood sugar control might not cut the risk of cardiovascular disease for older adults with long-term type 2 diabetes, but it could help protect their vision, kidneys and nerves.
Having high blood sugar (also called blood glucose) for a long time can cause damage to many parts of the body, including the eyes, kidneys, blood vessels and the heart. This damage to the heart and blood vessels can lead to heart attacks and strokes, according to the U.S. National Institute of Diabetes and Digestive and Kidney Diseases.
But some studies have shown that, for some people with diabetes, strict blood sugar control may not reduce the risk for cardiovascular disease.
One of the studies, published in The Lancet, included 10,251 participants, most about 60 years old, who'd had diabetes for an average of 10 years and had either a history of heart disease or two or more risk factors for it. They were assigned to either intensive glucose control therapy (A1C values of less than 6 percent), or standard therapy (A1C values of 7 to 7.9 percent).
A1C levels reveal average blood sugar levels over the preceding three months.
The study was stopped earlier than planned because the researchers noticed an increase in deaths among people in the intensive blood sugar control group. All of the participants were switched to standard therapy until the five-year follow-up ended.
There were no cardiovascular benefits for those on tight glucose control, who were at risk for very low blood sugar and gained more weight than those on standard therapy. But intensive glucose control did delay the onset of albuminuria (protein in the urine), which is associated with kidney failure, and some eye complications and nerve problems, the investigators found.
"The observed benefits associated with intense glycemia management should be weighed against higher total and cardiovascular-related mortality, weight gain, and severe hypoglycemia in patients at high risk of cardiovascular disease," the researchers wrote. They concluded that a "target of 6 percent or less with present strategies seems imprudent."
However, Dr. Faramarz Ismail-Beigi, the study's lead author and a professor of medicine at Case Western Reserve University and University Hospitals in Cleveland, said that the findings apply to only a certain group of people with diabetes.
And, Dr. Ronald Klein, of the University of Wisconsin School of Medicine and Public Health in Madison, said that, despite the findings, it's still crucial for diabetics to control their blood sugar levels -- but perhaps not as intensively as was previously thought necessary.
Technological improvements are needed to normalize diabetics' blood sugar without causing it to drop dangerously low, suggested Klein, who wrote a commentary that accompanied publication of the study.
On the Web
To learn more about diabetes, visit the U.S. National Institute of Diabetes and Digestive and Kidney Diseases. http://www.diabetes.niddk.nih.gov/dm/pubs/overview/index.htm
SOURCES: HealthDay News; Faramarz Ismail-Beigi, M.D., professor, medicine, Case Western Reserve University, University Hospitals of Cleveland; Ronald Klein, M.D., Ph.D., professor, department of ophthalmology and visual sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wis.; June 29, 2010, The Lancet, online; U.S. National Institute of Diabetes and Digestive and Kidney Diseases (www.diabetes.niddk.nih.gov)
Author: Robert Preidt
Publication Date: July 31, 2011
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