Diabetes in itself does not contribute to dementia, but poorly controlled diabetes has been linked to a higher risk for both cognitive impairment and dementia in a new study published in the Alzheimer’s & Dementia journal. With proper type 2 diabetes support, the risk of dementia has been seen to plummet extensively.
It’s been long known that while having diabetes has been linked to a higher risk of dementia, it hasn’t always been clear as to what degree of dementia may develop due to an elevated level of blood glucose. It has also been seen that by reversing type 2 diabetes, it will greatly decrease blood glucose levels thereby helping reduce the risk for dementia significantly.
In the latest study, researchers were particularly interested in whether elevated blood glucose levels contributed to cognitive impairment in people without dementia, or to developing dementia in people with cognitive impairment. They took a particular interest in this because of the uncertainty as to whether elevated blood glucose levels raise the risk for a precursor to dementia.
The Swedish National Study on Aging and Care-Kungsholmen study had 2,522 adults who participated, all of whom were residents of Central Stockholm. The participants ranged from 60 to 102 years of age, with an average age of 72.3 years. None of the participants had dementia, and 1,840 of these participants didn’t have any cognitive impairment of any kind, while 682 participants had cognitive impairment without dementia. When it came to type 2 diabetes, 217 participants had it, 860 participants had prediabetes, while the rest of the participants had normal blood glucose levels (this included people with type 1 diabetes or a number of other health conditions that were excluded from this study). The participants were followed for 12 years from 2004 until 2016, during which time, a variety of health measurements were taken, and their cognitive status was monitored.
During the follow-up period, 484 people, about 26.3%, in the group without cognitive impairment died, while 311 people in the group with cognitive impairment died which made up about 45.6% of the group. Another 391 people in the group without cognitive impairment, and 142 in the group with cognitive impairment, dropped out of the study.
By the end of the study, there had been 544 new cases of cognitive impairment among participants who began the study without the condition. Among participants who started out with cognitive impairment, there had been 151 new cases of dementia. After adjusting for the age and the sex of the participants, the researchers found that the new cases of cognitive impairment were 36.4 per 1,000 people for participants with normal blood glucose levels, 44.6 for those with prediabetes and 54.3 for those with diabetes.
The rate of new dementia for those who started off with cognitive impairment was 36.7 for those with normal blood glucose levels, 40.5 for those with prediabetes and 46.7 for those with diabetes.
After researchers adjusted the data further to account for more factors that are known and associated with affecting the risk for cognitive problems such as age, sex, weight, education level, physical activity, body mass index, heart disease, high blood pressure and other factors, they found that when compared with participants who had normal blood glucose levels, those with prediabetes were 12% more likely to develop cognitive impairment. People with diabetes were 34% more likely to develop cognitive impairment. When looking at the data, the participants who started out with cognitive impairment, when compared to those participants with normal glucose levels, were 19% less likely to develop dementia. And those with diabetes were 7% more likely.
However, researchers also noted that there was a major difference between participants with well controlled diabetes that was defined as an A1C level (a measure of long-term blood glucose control) below 7.5%, and those with diabetes that were poorly controlled when it came to the risk of cognitive impairment or dementia. When comparing the two groups of participants, those with well controlled diabetes were 20% more likely to develop cognitive impairment, whereas those whose diabetes were not well controlled, were 101% more likely to develop cognitive impairment. Amongst those participants who started out with cognitive impairment compared with those who had normal glucose levels, those with well controlled diabetes were 26% less likely to develop dementia, while those with poorly controlled diabetes were 187% more likely to develop dementia.
The Conclusion of The Study
Researchers have concluded that while having diabetes in itself didn’t increase the risk of dementia, having diabetes that was poorly controlled drastically increased the risk for dementia among people with cognitive impairment. These results show the importance of maintaining a good blood glucose control in older people with type 2 diabetes who are at a greater risk for cognitive impairment or dementia.