Of all the risk factors for dementia and impaired cognitive function, diabetes and obesity have to be the two most important issues that we need to deal with now. The burgeoning incidence of obesity and diabetes in the community and especially in young people is frightening. These young people are not just at increased risk of cardiovascular disease, cancer, and premature death. They have a far greater risk of developing cognitive impairment and dementia as adults.
What were the recent findings?
A study published in the July 30th issue of Diabetologia, reported that MRI brain scans of obese kids with type 2 diabetes show brain abnormalities, and on mental testing reduced cognitive performance. These kids will be functioning less well academically at school.
The study looked at a group of 18 obese adolescents with type 2 diabetes and another group of similarly obese adolescents who hadn’t yet developed significant insulin resistance or type 2 diabetes. This is the first time that cognitive deficits as a consequence of obesity with diabetes have been shown in this age group. Previous studies have looked at older people where similar abnormal brain findings on scans had been attributed to be the result of vascular disease, rather then a direct effect on the brain by the diabetes itself.
Both groups of adolescents came from similar socio-economic backgrounds and ethnicity.
They were asked to complete some mental tests. The results of group with diabetes were significantly lower in the areas of memory, spelling and overall academic function. They also showed white matter abnormalities on brain scans.
Dealing with insulin resistance may be the key.
The results highlight the urgent need to address both obesity and diabetes. More and larger studies need to be undertaken to verify these findings and to then get government and health professional support so that effective health programs can be developed and implemented to deal with this rising tide of obesity and diabetes. The challenge will be to be able to help kids already diagnosed with insulin resistance, to improve their insulin sensitivity through weight management, healthy eating and exercise.
A separate study published in August, looked at the relationship between insulin resistance, type 2 diabetes and the development of plaques in the brain. Brain plaques are associated with the neurodegenerative disease of Alzheimer’s. Insulin resistance has been described as a pre-diabetic state. In insulin resistance, the insulin hormone our body produces is becomes less effective in exerting its effect on helping to lower the blood sugar to normal. This study followed an older population of 135 Japanese subjects aged over 67 years over a period of 10 to 15 years. They underwent several glucose tolerance tests to measure their blood sugar levels and were monitored for symptoms of Alzheimer’s disease over that time. After their deaths their brains were autopsied and it was found that those who had had at least three abnormal glucose tolerance tests had a greater risk of developing plaques in their brain. In other words, having insulin resistance was associated with an increased likelihood of the person developing brain plaques that are commonly found in patients with Alzheimer’s disease. Further studies will now need to be undertaken to see whether insulin resistance is associated as being a cause of this plaque formation.
The real risk of failing to take action now.
If we continue to fail to address the issues society currently has in terms of the level of our overall inactivity, obesity and diabetes then I believe we are setting ourselves up to add to the already significant social and economic burden of increasing rates of dementia we are anticipating over the next few decades. It won’t just be the baby boomers that are at risk of dementia simply because of their increasing age. We have yet to count the impact of younger people already burdened with the significant health impairment of obesity and diabetes that will be adding to this toll.
P.L. Yau, D.C. Javier, C.M. Ryan, W.H. Tsui, B.A. Ardekani, S. Ten and A. Convit. Preliminary evidence for brain complications in obese adolescents with type two diabetes mellitus. Diabetologica,2010;DOI; 10.1007/s00125-010-1857-y
T.Matsuzaki, K. Sasaki, Y.Tanizaki, J. Hata, K. Fujimi, Y. Matsui, A. Sekita, S.O. Suzuki, S. Kanba, Y. Kiyohara, and T. Iwaki. Insulin resistance is associated with the pathology of Alzheimer's disease. The Hisayama Study. Neurology,2010;DOI:10.1212/WNL.0b013e3181eee25f