Diabetes and other metabolic disorders as well as psychiatric symptoms like depression increased the risk for developing dementia among people with mild cognitive impairment, new data published in the American Journal of Psychiatry suggest.
“Public health campaigns encouraging early help seeking have increased rates of mild cognitive impairment diagnosis in Western countries, but we know little about how to treat or predict dementia outcomes in persons with the condition,” lead study author Claudia Cooper, PhD, MRCPsych, of the University College London in the United Kingdom, and colleagues wrote in the study.
For the study, Dr. Cooper and colleagues reviewed data from 62 separate studies that followed a total of 15,950 people diagnosed with mild cognitive impairment, according to a press release.
Results indicated that among people with mild cognitive impairment, those with diabetes were 65% more likely to progress to dementia.
Specifically, diabetes and prediabetes were linked to an increased risk for conversion from amnestic mild cognitive impairment to Alzheimer’s dementia, with one study suggesting a lower risk with treated vs. untreated diabetes. Diabetes also appeared to increase the risk for conversion from any-type or nonamnestic mild cognitive impairment to all-cause dementia.
Similarly, metabolic syndrome and prediabetes predicted all-cause dementia in those with amnestic and any-type mild cognitive impairment, respectively.
The Mediterranean diet, however, appeared to decrease the risk for conversion to Alzheimer’s dementia, according to the study results.
The researchers also found that people with psychiatric symptoms were more than twice as likely to develop dementia, with depressive symptoms predicting conversion from any-type mild cognitive impairment to all-cause dementia in epidemiological but not clinical studies.
Lower serum folate levels were also found to predict progression from any-type to all-cause dementia.
“There are strong links between mental and physical health, so keeping your body healthy can also help to keep your brain working properly,” Dr. Cooper said in the release.
“Lifestyle changes to improve diet and mood might help people with mild cognitive impairment to avoid dementia, and bring many other health benefits. This doesn’t necessarily mean that addressing diabetes, psychiatric symptoms and diet will reduce an individual’s risk, but our review provides the best evidence to date about what might help.”
Senior study author Gill Livingston, MD, FRCPsych, also of the University of College London noted that randomized, controlled trials are now necessary.
Alan Thompson, MD, FRCP, Dean of the University of College London Faculty of Brain Sciences also commented on the findings.
“This impressive systematic review and meta-analysis from the Faculty of Brain Science’s Division of Psychiatry underlines two important messages. Firstly, the impact of medical and psychiatric comorbidities in individuals with mild cognitive impairment, and secondly, the importance and therapeutic potential of early intervention in the prevention of dementia,” Dr. Thompson said in the release.
“Confirming these findings and incorporating appropriate preventive strategies could play an important part in lessening the ever-increasing societal burden of dementia in our aging population.”