High Blood Sugar and Dementia: No Diabetes Needed

Henry R. Black, MD


September 19, 2013

Study Findings

The primary finding is that the blood sugar levels, which they integrated using both random and fasting blood sugar levels, predicted the development of incident dementia. (Dementia was diagnosed using a scale that is well validated; I cannot comment on whether that is an appropriate scale or not.) They also found that as blood sugar rose within that group, the likelihood of developing dementia increased whether or not you had diabetes.

This is a very important finding. But the important thing is, what do we do about it? How do we get people to aim for a lower blood sugar?

They asked people whether they exercised. People said they did. I am not sure how accurate that really is. How much exercise did they do? Did they work up a sweat? Did they just do the so called 5-minute mosey, or did they actually increase their heart rate and get some cardio protection? We have to depend on what our subjects tell us, but the authors did not clarify this further.

The group who did not have diabetes had an average blood sugar of about 100 mg/dL as opposed to the diabetics whose levels were in the 170s. There was a J-shaped relationship between blood sugar and dementia in the diabetics. People who had a blood sugar of 140 mg/dL on average had more dementia, but the rates of dementia then went down to essentially zero and then went up again as the blood sugar rose higher. The nondiabetics had more of a straight-line correlation from the lowest level to the highest level.

Although we do not need more encouragement to get people to watch their weight, to exercise, to be careful, I think this is another reason to support these efforts. People probably are more afraid of dementia than anything else, and that is an appropriate fear. I hope this gives additional encouragement to exercise, to keep our weight down and to get our blood sugar checked frequently so we can focus on this. Thank you very much.