Even 'High-Normal' Blood Sugar Tied to Brain Shrinkage
Scans show memory, thinking regions shrank in those at high end of 'normal' range; more study needed
TUESDAY, Sept. 4, 2012 (HealthDay News) -- People with blood sugar levels at the high end of the normal range may be at increased risk for brain shrinkage that occurs with aging or dementia, according to a new study.
While numerous studies have shown a link between type 2 diabetes and brain shrinkage and dementia, little has been known about whether people with blood sugar levels at the high end of "normal" also experience these brain effects, the study authors noted.
To examine the issue, Australian researchers looked at 249 people, aged 60 to 64, with normal blood sugar levels. The participants had brain scans at the start of the study and four years later.
The brain scans revealed that people with higher fasting blood sugar levels within the normal range were more likely to have a loss of brain volume in the areas of the hippocampus and the amygdala -- areas involved in memory and thinking skills -- than those with lower blood sugar levels.
After allowing for factors such as age, high blood pressure, smoking and alcohol use, the researchers concluded that having blood sugar levels at the high end of the normal range accounted for 6 percent to 10 percent of the brain shrinkage.
The study was published in the Sept. 4 issue of the journal Neurology.
While the study found an apparent link between high-normal blood sugar and brain shrinkage, it didn't prove a definitive relationship.
"These findings suggest that even for people who do not have diabetes, blood sugar levels could have an impact on brain health," study author Nicolas Cherbuin, of the Australian National University in Canberra, said in a news release from the American Academy of Neurology. "More research is needed, but these findings may lead us to re-evaluate the concept of normal blood sugar levels and the definition of diabetes."
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