They said women with the shortest arm spans were 50 percent more likely to develop dementia and Alzheimer's disease than women with longer arm spans. And the longer a woman's leg from floor to knee, the lower her risk for dementia.
In men, only a shorter arm span was linked with higher dementia risk, according to the study, which was published in the journal Neurology.
The researchers said several studies have suggested that early life environment plays a role in susceptibility to chronic disease in later life. Short limbs may be a sign of nutritional deficits early in life that ultimately play a role in brain development.
"Body measures such as knee height and arm span are often used as biological indicators of early life deficits, such as a lack of nutrients," said Tina Huang of Tufts University in Boston, who led the study.
Other studies have found a link between limb length and dementia in populations in Asia, and Huang wanted to see if the trend would hold true in a U.S. population, where 80 percent of height is thought to be inherited.
She and colleagues studied 2,798 people for an average of five years and took knee height and arm span measurements. Most people in the study were white, with an average age of 72.
By the end of the study, 480 had developed dementia.
"We found that shorter knee heights and arm spans were associated with an increased risk of dementia," Huang and colleagues wrote.
"Overall, our findings suggest that as they do in the Korean populations, anthropometric measures of short stature, even as defined by Western standards, similarly predict risk for dementia," they wrote.
Last Mod: 06 Mayıs 2008, 14:44