The strongest predictor of dementia was the presence of the ApoE4 gene in participants. ApoE aids in the development of lipoproteins, which carry cholesterol, fats, and vitamins throughout the body, including the brain. The E4 version of the gene is linked to late-onset Alzheimer’s disease. Some studies appeared to show the E4 gene mutation prevented clearing of the amyloid protein linked with Alzheimer’s, though findings are not clear. People can inherit one or two copies of the E4 gene, with risk increasing exponentially with each copy.
Most noteworthy, though, was the finding diabetes was as strong of a predictor of dementia as the ApoE4 gene. Type 2 diabetes is commonly caused by poor diet, lack of physical fitness, and excess weight, causing the body to not use insulin properly to regulate blood sugar.
High blood pressure, also known as hypertension, was also heavily linked with dementia risk in participants. This is the first study to additionally link pre-hypertension—a condition prior to hypertension—with the risk of dementia.
Data analysis also found some correlations between dementia and the participant’s race. For example, while the ApoE4 gene was more common in white participants, black participants were more likely to develop dementia. Probability increased for black participants who did not graduate high school. There was, however, no link between race, dementia, and cardiovascular risk factors.
Dr. Gottesman is already planning further research on the link between race and dementia.
More details of the research and findings were published in the August 2017 edition of JAMA Neurology journal, which is funded by NINDS.