Delaying a Critical Growth Spurt Can Lead to Short Stature
Wednesday, September 3, 2008
By: Kevin Hattori

Lengthy or repeated childhood illnesses or malnutrition during the critical transition from infant to child can delay the onset of a critical growth spurt between infancy and childhood, leading to shorter than normal stature as an adult, according to new research.

Children who experience this delayed growth-between six and 12 months of age-could pass on this tendency to shorter stature to successive generations, say Professor Ze'ev Hochberg of the Technion-Israel Institute of Technology and Kerstin Albertsson-Wikland of the University of Gothenburg in Sweden.

In fact, the delayed growth spurt may be "responsible for 44 to 50 percent of cases of unexplained shortness for unknown reason among children and adults in developed countries and much more in developing nations," the researchers argue in their report in the journal Pediatric Research (July 2008).

Delayed growth may be an evolutionary strategy that allows humans to adjust their body sizes in response to the stresses of infection or lean environmental times, the researchers suggest. Adaptations that lead to smaller body size would be beneficial in these cases, since smaller bodies can survive and thrive on less energy than larger bodies.

"This adaptation is even transferred to future generations, so an energy crisis in one of the parents-usually the father-or grandparents will carry on to their descendants and cause shortness up to the third or fourth generation," Hochberg said.

Hochberg said the effects of the delay are substantial: the later a child begins the growth spurt, the smaller the child will be as an adult. For each month the growth spurt is delayed beyond the six to 12-month critical period, boys and girls lose .0.9 centimeters (0.3 inches) of height.

Children who experience delayed growth in this period are usually normal weight at birth and have otherwise normal growth patterns, the researchers said. But in their analysis of 176 growth charts for these children, "we did not encounter a single case of catchup growth," Hochberg said.

The delayed transition from infant to child appears to be linked to the development of two hormones called growth hormone and insulin-like growth factor, which set in their activity as the child transits from infancy to childhood, the researchers said.

And although parents might like to know if there's anything they can do to affect the timing of the growth spurt so that their child ends up standing tall among his or her peers, any thoughts on how to manipulate the growth period "require further investigation," Hochberg said.

The Technion-Israel Institute of Technology is Israel's leading science and technology university. Home to the country's winners of the Nobel Prize in science, it commands a worldwide reputation for its pioneering work in nanotechnology, computer science, biotechnology, water-resource management, materials engineering, aerospace and medicine. The majority of the founders and managers of Israel's high-tech companies are alumni. Based in New York City, the American Technion Society (ATS) is the leading American organization supporting higher education in Israel, with 22 offices around the country.

For more information, contact Kevin Hattori via email or call 212-407-6319.