High blood sugar levels may mean more than diabetes – your risk of dementia can increase with higher glucose levels as well.
There are many different types of dementia and many different causes; however, Alzheimer’s is the most common form of dementia and more than five million Americans have Alzheimer’s disease, according to the Alzheimer’s Association.
Dementia is caused by damage to the brain cells – this damage can result from a number of factors, from brain injuries to having diabetes. In a new study researchers look at the connection between high glucose levels and the risk of developing dementia.
Dr. Paul Crane, lead author and associate professor of medicine at the University of Washington, and his team of researchers wanted to know if high glucose levels increased the risk of a person without diabetes to develop dementia.
The participants from this study were from the Adult Changes in Thought study, and included 839 men and 1,228 women with a mean age of 76.
Of these participants, 232 people had diabetes and 1,835 people didn’t. During the median follow-up 6.8 years 524 people developed dementia (74 with diabetes and 450 without diabetes).
Those participants without diabetes that had higher glucose levels within the preceding five years were related to an increase in dementia.
These participants had glucose readings of 115 mg per deciliter were 18 percent more likely to develop dementia compared to those with glucose readings of 100 mg per deciliter or lower.
The participants with diabetes whose average glucose readings were 190 mg per deciliter had a 40 percent higher chance of developing dementia than those with an average of 160 mg per deciliter.
Blood Sugar and Dementia: Questions and Answers with Dr. Crane
1. According to your study, “dementia developed in 524 participants (74 with diabetes and 450 without” can you explain why the proportion of people who developed dementia among people with diabetes be expected to be higher than that among people without diabetes? Dr. Crane explained:
“We did not set out to answer the question of whether diabetes was a risk factor for dementia. That question has been asked a lot of times and would require analyses different than what we did. We treated people with diabetes (which we defined as treatment for diabetes) separately from people who did not have diabetes in our modeling.
There are a couple of things that make this complicated:
1. Some people developed diabetes after they joined the study. They are counted as people with diabetes in the numbers you quote (I think, not looking at the paper) but they would not have had diabetes for very long.
2. People with long-established diabetes have a competing risk for death. If you die before you develop dementia, you don’t develop dementia. A good study of the “is diabetes a risk factor for dementia” question would need to deal with competing risks for death. We did not do this because within people who do not have diabetes, there is probably not a big difference in mortality rates associated with different glucose levels. But if we were looking at diabetes yes/no we would have had to address this.”