Thursday, March 27, 2008

Big Belly can result in later Alzheimer disease

The revered Dr. Michael Beckman sent me a recently published Associated Press article by Malcom Ritter on research suggesting that “having a big belly in your 40s can boost your risk of getting Alzheimer's disease or other dementia decades later.”
By ‘big belly’ the researchers, headed by Rachel Whitmer of the Kaiser Permanente Division of Research in Oakland, Calif, are not talking simply about weight. Although obesity can increase the risk of later Alzheimer disease, there seems to be “a separate risk from storing a lot of fat in the abdomen” even for people who were not overweight.
This is another example of how traits which predispose to the development of heart disease are also linked to later dementia.

Key excerpts from the article are as follows:
“That abdominal fat, sometimes described as making people apple-shaped rather than pear-shaped, has already been linked to higher risk of developing diabetes, stroke and heart disease.
"Now we can add dementia to that," said study author Rachel Whitmer.
“She and others report the findings in Wednesday's online issue of the journal Neurology.
Analysis found that compared to people in the study with normal body weight and a low belly measurement:
- Participants with normal body weight and high belly measurements were 89 percent more likely to have dementia.
- Overweight people were 82 percent more likely if they had a low belly measurement, but more than twice as likely if they had a high belly measurement.
- Obese people were 81 percent more likely if they had a low belly measurement, but more than three times as likely if they had a high measurement.”

Thanks for the article, Dr. Beckmann.

12 comments:

Cathy Goodwin, PhD said...

It would be helpful to get access to the raw statistics. If big-bellied folks had a dementia rate of 3% and the skinny folks only 1%, the difference would be 300%.

I would want to see a breakdown by males and females and by age of dementia onset.

The articles I've seen all seem to be generated by the same press release. It wouldn't be the first time that statistics were manipulated to tell a good story.

heather@grantham.com said...

Assuming it to be true that persons who are not otherwise prone to being overweight and therefore carry 'belly fat' do so as a result of lifestyle choices, would it not be more likely that these choices are the cause (diet, low physical and/or mental exercise levels) of increased incidence of dementia? ie. These conditions are co-morbid rather than the belly fat being causal?

JD said...

Wow, your readership is growing!

Prof. EGS would like to add his comment: "Some people don't have enough to do!"

I, too, am skeptical of these study results.

JD said...

By the way, you've now got Alzheimer ads on there. The toe stuff is gone.

Brian E. Moore, MD (left) said...
This comment has been removed by the author.
Brian E. Moore, MD (left) said...

Good points about the devil being in the details regarding this study. The artcle is e-published in advance on the Neurology website, but you have to be a subscriber to access it. The methods section should shed some light on whether this study is worth paying attention to. In the meantime, it might be a good idea to keep doing those sit-ups!

Brian E. Moore, MD (left) said...

To answer Cathy Goodwin's question, this is from the results section of the article under discussion: "Age-adjusted incidence
rates of dementia by quintiles of sagittal abdominal diameter showed an increase in risk of dementia across quintiles with a steep increase in incidence among
those in the fifth quintile of sagittal abdominal diameter (324 events per 10,000
person-years vs 214 events for those in the first
quintile). There was no significant increase in dementia
incidence by quintile of thigh circumference."

Brian E. Moore, MD (left) said...

To answer Heather's question regarding belly fat being comorbid rather than causal of dementia, the article has this to say:
"Central obesity is not a problem limited to those who are overweight or obese; indeed, reports have found that among those not overweight, a centralized
distribution of adiposity is associated with an increased risk of insulin resistance, diabetes,
and coronary artery disease." The lifestyle choices that Heather mentions would predispose to obesity, not central body fat accumulation specifically.

Thanks to John Donahue for providing an advance copy of the article.

JD said...

I would like to get Rachel Whitmer's response. Have you sent her a link to this blog?

Brian E. Moore, MD (left) said...

Yes I did send Rachel Whitmer a notice that her article was features in the blog, but I've not heard a response as of yet.

Niel said...

Wondering... if the risk of any brain disease may be more closely tied to amount of blood flow through the brain (via exercise, or lack thereof as an increased risk) rather than through a secondary marker like central weight accumulation.

Brian E. Moore, MD (left) said...

Neil,
I bet you that cerebrovascular health would be a measure of risk for dementia. But how to easily and inexpensively measure that in a routine clinical setting is the question. A secondary measure like abdominal fat may be a less perfect, but more practical, test from a clinical perspective.