High Blood Glucose Levels Linked to Dementia

Adults with a high blood sugar level may have an increased risk of developing dementia compared with those who have a normal blood sugar level.

With the aging of the population, dementia has become a major threat to public health worldwide, while the rate of obesity is also increasing, with a parallel increase in the rate of diabetes.

Scientists at the University of Washington School of Medicine (Seattle, WA, USA) analyzed various variables of 2,067 participants without dementia aged 65 and over. In order to examine the relationship between glucose levels and the risk of dementia, they analyzed the median measurements of glycated hemoglobin levels (HbA1C) and glucose levels over a period of 6.8 years.

The results of the study revealed that in the participants with diabetes, the risk of dementia was 40% higher for those with an average glucose level of 190 mg/dL, compared with participants who had an average glucose level of 160 mg/dL. The results also showed that in the participants without diabetes, the risk of dementia was 18% higher for those with an average glucose level of 115 mg/dL versus those with an average of 100 mg/dL.

The investigators said that including both glucose levels and glycated hemoglobin in the measurements was the key as blood sugar levels rise and fall throughout the day, but glycated hemoglobin does not vary as much over short periods. However, they add that these results do not necessarily mean that people should eat foods with a lower "glycemic index," but exercise may help.

Paul K. Crane, MD, MPH, an associate professor and lead author, said, “The most interesting finding was that every incrementally higher glucose level was associated with a higher risk of dementia in people who did not have diabetes. There was no threshold value for lower glucose values where risk leveled off. Your body turns your food into glucose, so your blood sugar levels depend not only on what you eat but also on your individual metabolism: how your body handles your food."

The authors concluded that although their results show that higher glucose levels are linked to higher dementia risk, there is no data to suggest people who make changes to lower their glucose levels will reduce the risk of dementia. The study was published on August 8, 2013, in the New England Journal of Medicine (NEJM).

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University of Washington School of Medicine