Navigation Links
High estrogen levels associated with dementia in older men

A prospective population-based study has found that higher estrogen levels in older men are associated with an increased risk of dementia. By contrast, levels of testosterone were not associated with cognitive decline. The study is in the August issue of Annals of Neurology, a journal published by John Wiley & Sons. (http://www.interscience.wiley.com/journal/ana).

As our population ages, the impact of dementia will grow. By the year 2050, some 13 million Americans could have Alzheimer's disease, which is the most common cause of dementia. Researchers are searching to understand risk factors and some studies have suggested that sex hormones play a role. One large study showed that women receiving estrogen therapy had an increased risk of cognitive impairment and dementia. However, the evidence for how testosterone levels affect men is contradictory.

To better understand the role of sex hormones in dementia, researchers led by Mirjam Geerlings, Ph.D. of the University Medical Center Utrecht, studied whether older men's levels of testosterone and estrogen were associated with their risk of cognitive decline and developing dementia, including Alzheimer's disease.

They examined data from the prospectively studied population-based cohort of 2974 Japanese-American men aged 70 to 91 who participated in the Honolulu-Asia Aging Study. Participants showed no signs of dementia at baseline in 1991-1993, at which time fasting blood samples were drawn. The researchers measured the levels of testosterone and estradiol, the major estrogen in humans, in the samples and the men were reexamined for evidence of cognitive decline or dementia in 1994-1996 and 1997-1999 using the Cognitive Abilities Screening Instrument (CASI). At each exam, researchers also collected physical, demographic and medical information.

A total of 2300 men completed the study and 223 were diagnosed with incident dementia during the follow-up period. 134 men developed Alzheimer's disease, and 44 developed vascular dementia. The researchers used Cox regression analyses, adjusting for age and other covariates, to see if hormone levels were associated with risk of developing dementia

"Levels of bioavailable testosterone were not associated with risk of cognitive decline and incident dementia," they report. "In contrast, higher levels of bioavailable estradiol were associated with an increased risk for cognitive decline and Alzheimer's disease." For each standard deviation increase in estradiol level, the risk for the disease went up by 25 percent. Furthermore, compared with the lowest tertile of estradiol, men in the middle and highest tertile had .24 and .28 points lower CASI scores, respectively, for each year increase in age.

The researchers hypothesize that the estradiol association could be explained by increased aromatase activity in the brain which may be associated with a neurodegenerative process. It is then possible that the high levels of estradiol are a consequence or early marker of Alzheimer's disease rather than a cause.

Some caution is needed when interpreting the results, as, due to death or refusal, some men could not be given a diagnosis of dementia or follow-up cognitive testing.

In conclusion, the authors report, "our findings of an increased risk of cognitive decline and Alzheimer's disease associated with higher estradiol are similar to recent findings in postmenopausal women. Further studies are needed to examine whether there are mechanisms by which estradiol may increase risk of cognitive decline and dementia."


'"/>

Source:John Wiley & Sons, Inc.


Related biology news :

1. Harmful chemicals may reprogram gene response to estrogen
2. Compounds in plastic packaging act as environmental estrogens altering breast genes
3. Tamoxifen-like drug suggests new ways to selectively block estrogen
4. Researchers uncover mechanisms of estrogen in promoting cell death in breast cancer
5. Ultra low-dose estrogen shown safe for post-menopausal women
6. New path from estrogen to survival in breast cancer cells described
7. Changing length of days reverses how estrogen affects aggressiveness in mice
8. Molecular atlas provides new tool for understanding estrogen-fueled breast cancer
9. New lab technique identifies high levels of pathogens in therapy pool
10. Scientists at Galileo Pharmaceuticals confirm inflammatory response linked to glucose levels
11. MERIS monitoring tracks planetary photosynthesis levels
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:2/3/2016)... 2016 --> ... "Automated Fingerprint Identification System Market by Component (Hardware and ... & Finance, Government, Healthcare, and Transportation) and Geography - ... is expected to be worth USD 8.49 Billion by ... and 2020. The transformation and technology evolution from the ...
(Date:2/2/2016)... This BCC Research report provides a ... the recent advances in high throughput ‘omic platforms ... forward. Includes forecast through 2019. Use ... opportunities that exist in the bioinformatic market. Analyze ... well as IT and bioinformatics service providers. Analyze ...
(Date:2/2/2016)... MOUNTAIN VIEW, Calif. , Feb. 2, 2016 ... diabetic retinopathy market, Frost & Sullivan recognizes US-based ... North America Frost & Sullivan Award for New ... technology provider in North America ... standard in the rapidly growing diabetic retinopathy market. ...
Breaking Biology News(10 mins):
(Date:2/9/2016)... BERG, a biopharmaceutical company uncovering health ... announced the appointment of Jason Haddock ... Haddock brings to BERG over 20 years of ... senior financial functions at pharmaceutical companies, as well ... Niven R. Narain , BERG,s ...
(Date:2/8/2016)... , Feb. 8, 2016  CytRx Corporation (NASDAQ: ... company specializing in oncology, today announced that it ... agreement with Hercules Technology Growth Capital, Inc. and ... million in financing. --> ... $25 million of financing under the loan and ...
(Date:2/8/2016)... Feb. 8, 2016  BioElectronics Corporation (OTC Pink: ... announced today that it is responding to a ... the Securities and Exchange Commission posted on the ... Chairman of the Board of BioElectronics Corporation and ... Administration at The Fuqua School of Business, Duke ...
(Date:2/8/2016)... Conn. , Feb. 8, 2016  NanoViricides, Inc. (NYSE MKT: ... its CEO, Eugene Seymour , MD, MPH, will present information ... at the Waldorf-Astoria Hotel in New York City ... will be in the Windsor Room at 5:30PM EST. Registered attendees ... New York City . --> ...
Breaking Biology Technology: