Baldness is inevitable in many aging men, but it may be of particular concern to men who are short.
A new study has found that males of short stature are at increased risk of losing their hair prematurely, in addition to a number of other health conditions.
The study analyzed the genomes of more than 20,000 men, about half of whom had gone bald well before they turned 50. The other half of participants had no hair loss and were used for comparison.
The study included men from the United States, Switzerland, the Netherlands, Germany, the United Kingdom, Greece and Australia. The researchers identified 63 alterations in the human genome that increase the risk of premature baldness. And in many instances, the DNA regions overlapped with genes for short stature.
The investigators at the University of Bonn in Germany also found overlaps in bald men for a number of other physical characteristics and illnesses.
These included genes not only coding for shortness but also for traits predisposing the men to early puberty and an increased risk of prostate cancer. There's also evidence that Parkinson's disease is more common in men who start going bald at a younger age.
Geneticist Stefanie Heilmann-Heimbach, a lead author of the study, noted that researchers were hunting for baldness genes in particular when they made the other findings.
Until now, she said, associations between baldness and early age of puberty and prostate cancer had been noted only in population studies, "so with this study, this was really the first time that so many traits popped up."
The work was published in the journal Nature Communications.
Heart disease link
The researchers also discovered genes that may put shorter males at a higher risk for heart disease, but they said that association was less clear than the one for early puberty. Researchers found the genes for heart disease in the same region of the genome with genes that may play a role in a reduced risk.
But back to the hair. It's been noted that genetics are not destiny, and Heilmann-Heimbach said young men who are short should not worry that they are necessarily going to lose their locks at an early age.
"All the other family members — if they kept their hair and are also somehow the same body height, then I wouldn't be too afraid to lose my hair," she said.
Investigators said their gene study finding an association between baldness, short stature and other health conditions was only a first step. They said they were eager to discover the underlying biological mechanisms that increase the risk of short men losing their hair at an early age. Understanding that may help provide more clues as to why shorter males are also at increased risk for other diseases and conditions.