Insulin resistance could increase risk of Alzheimers in middle-aged adults

People who develop insulin resistance at late-middle age could be more likely to develop Alzheimers disease, according to new research.
The study, which was conducted by researchers at the University of Wisconsin School of Medicine and Public Health, found that adults with insulin resistance had lower glucose metabolism in the lower left medical temporal lobe of the brain, an area related to the memory function.
The researchers analysed the data of 150 adults, all of whom were aged between 48 and 71. Moreover, all of the adults were cognitively normal, but they did have a higher risk of Alzheimer’s through their parents.
The researchers used cognitive tests and MRI scans to assess the brain activity of the participants, then measured their insulin and glucose levels after 12 hours of fasting.
They found that higher levels of insulin resistance were linked to lower glucose metabolism across several areas of the brain, including the frontal, lateral parietal, lateral temporal and medical temporal lobes. The strongest link, though, was in the left medial temporal lobe. Low glucose metabolism in this area is associated with degraded memory function.
The study did not, however, find a causal link. All the researchers know is that insulin resistance and low glucose metabolism in the left medial temporal lobe occur simultaneously. More research is needed to confirm a causal link.
Neither did the research suggest that every middle-aged adult with insulin resistance will develop Alzheimer’s disease. It merely found that the risk might be increased. The study is useful because it adds to the rapidly expanding body of knowledge about diabetes and Alzheimer’s disease, and because it provides direction for future studies on the subject.
“This study provides evidence that insulin resistance is associated with brain glucose metabolism in a late middle-aged cohort enriched for [Alzheimer’s disease] risk factors,” wrote the researchers.
“The prevalence of [Alzheimer’s] continues to grow, and midlife may be a critical period for initiating treatments aimed at preventing or delaying the onset of [Alzheimer’s].”