Taller men may have a lower risk of dementia
18 February, 2020
A fresh longitudinal study that analyzed data from thousands of men found a connection between height and the likelihood of developing dementia.
Dementia - an umbrella term that encompasses various conditions involving cognitive impairment, the most typical which is Alzheimer’s - impacts around 50 million people worldwide, according to data from the World Health Organization (WHO).
There is currently no cure for dementia, and researchers are interested in pinpointing the countless possible risk factors as a way to facilitate early diagnosis and intervention.
Now, a fresh study from the University of Copenhagen, in Denmark, has found a link that was not explored much before: a link between height and dementia risk.
The research - led by assistant professor Terese Sara Høj Jørgensen - was spurred by previous studies’ ideas that height may correlate with risks to brain health.
Jørgensen and the team accessed data about height and eventual dementia diagnoses through conscription records and national registries. They have finally published their findings in the journal eLife.
“We wished to see if body height in teenagers is connected with diagnosis of dementia, while exploring whether intelligence test scores, educational level, and underlying environmental and genetic factors shared by brothers clarify the partnership,” Jørgensen explains.
Height may be highly relevant to dementia risk
The researchers looked at data from men born between 1939 and 1959. Their cohort included 666,333 individuals, of whom 70,608 were nontwin brothers and 7,388 were twins.
The men in this cohort had taken conscript board examinations between 1957 and 1984, and national registries had clinically followed them until 2016.
By analyzing data from these sources, the researchers found that 10,599 of the 666,333 men had developed a type of dementia at some time.
The researchers observed that there were a correlation between a man’s height and his dementia risk - specifically, men who were taller than average seemed to have a lower threat of dementia than men who were shorter than average.
Thus, if the mean height for men born in 1939 was 1.75 meters, for approximately every 6 centimeters over the mean height, there is approximately a 10% reduction in dementia risk.
The researchers adjusted their analysis for possible confounding factors, particularly education levels and intelligence test scores. When they did so, the partnership between height and dementia risk was reduced - however, not significantly.
When they compared results among siblings, the researchers discovered that the partnership between height and dementia risk was within brothers with different heights.
The partnership was also within twins, though the team admits that the results were less conclusive in this context.
Environmental factors could be at the root
Jørgensen and her colleagues note that, looking at the results, it appears unlikely a person’s genetic makeup alone explains the hyperlink between height and dementia risk.
Instead, they recommend that height - particularly short stature - may reflect environmental conditions during early life that may be the true risk factors for dementia.
“An integral strength of our study is that it adjusted for the potential role of education and intelligence in young men’s dementia risk, both which may build-up cognitive reserve and make this group less susceptible to developing dementia,” notes senior author Prof. Merete Osler.
“Following this adjustment, our results still indicate a link between taller body height in teenagers and a lower threat of dementia diagnosis later in life. Our analysis of brothers further shows that the association may have common roots in early-life environmental exposures, unrelated to family factors shared by brothers.”
- Prof. Merete Osler
The researchers advise that further longitudinal studies explore the links with environmental exposures in more depth.
Also, they caution that their findings might not connect with women. Other studies, they state, should ascertain whether biological sex is important in the partnership between height and dementia risk.
Source: www.medicalnewstoday.com
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