The research, released Friday, adds to the evidence that growth and development early in life influence the risk of a variety of diseases later on.
Earlier studies have found that short people are more prone to heart attacks. In this report, researchers zeroed in on the length of the upper leg and found an association both with the risk of diabetes and its precursor, called insulin resistance.
"I'm not saying thigh length determines diabetes," said Dr. Keilo Asao. "Perhaps some factor that affects thigh length also affects diabetes risk. It may be a marker of early life nutrition."
Asao, a researcher at Johns Hopkins University, presented the data at a meeting in Miami Beach of the American Heart Association. The study was based on a national health survey of 8,738 U.S. men and women.
Insulin resistance, also called impaired glucose tolerance, often precedes full-fledged diabetes. It occurs when the body cannot use insulin efficiently to turn sugar into energy.
The researchers found that the average thigh length of men and women with normal glucose tolerance was 15.8 inches. It was 15.4 inches for those with insulin resistance and 15.1 in those with diabetes.
Asao noted that leg length is determined by both genes and nutrition. While the thigh continues to grow until about age 20, how long it will get is determined by about age 4.
Two earlier European studies have looked at overall leg length and found a link with the risk of diabetes. The latest study is the first to examine this in a large group of Americans and to focus on the thigh.
Other researchers said that while the results are intriguing, they do not suggest anything people can do to avoid the risk of diabetes.
"I would not go out and get my thighs stretched, if that's possible," said Dr. Russell Luepker, head of epidemiology at the University of Minnesota.
He noted that obesity is the leading cause of diabetes, which is increasing rapidly and now afflicts about 7 percent of all Americans.
"We are in the midst of a diabetes epidemic, and we are all looking for reasons for that," he said. "Is this really an indicator of inadequate nutrition at some critical point in a person's life? This study raises that possibility."
Among other reports at the meeting Friday:
The importance of this change for heart health is unclear, though Gunderson said it may mean childbearing affects health in ways beyond weight gain.
By Daniel Q. Haney