THURSDAY, Sept. 3, 2009 (HealthDay News) -- Thin thighs might look good in jeans, but a new Danish study indicates they might also raise the risk of premature death and heart disease in both men and women.
That's not to say fat thighs confer any survival benefit, the researchers stressed. Rather, the study of nearly 3,000 men and women who were followed for more than 12 years found the ideal thigh measurement was in the neighborhood of 60 centimeters, about 24 inches.
The report, by researchers at Copenhagen University Hospital, was published in the Sept. 4 issue of BMJ.
A number of studies have linked cardiovascular risk to obesity, measured by either body-mass index (BMI, a ratio of weight to height) or waist circumference. "This is the first time that someone has related thigh size to pathology," said study author Berit L. Heitmann, a professor of nutritional epidemiology at the university's Institute for Dietary Studies.
The increased death risk for people with thin thighs "was found independent of abdominal and general obesity, lifestyle, and cardiovascular risk factors such as blood pressure and lipids," the researchers wrote.
Dr. Vivian Fonseca, chief of endocrinology at Scott & White Memorial Clinic in Temple, Texas, said: "It seems odd as to why a thin thigh may predict heart disease. However, it could represent that fat and muscle is not being deposited in the right place where it is needed, and certainly we know that fat in the wrong places, such as skeletal muscle and liver and pancreas, is associated with diabetes and may increase mortality. So the problem here may not be with the thin thighs, but where else the bulk is going."
The study authors offered their own theory: Thin thighs might suggest a lack of muscle mass, which can lead to insulin sensitivity and heart disease.
"Is this association plausible?" asked an accompanying editorial by Dr. Ian A. Scott, director of internal medicine and clinical epidemiology at Princess Alexandra Hospital in Brisbane, Australia. His answer: Maybe.
Given the relatively small number of people in the study and a somewhat weak relationship between thigh size and cardiovascular risk, "it seems unlikely that thigh circumference will be clinically useful," Scott wrote. "More research is needed to see whether measuring thigh circumference with a tape measure adds anything more to our clinical management than eliciting risk factors from the history, examining the cardiovascular system and measuring serum lipids."
"What would be useful would be studies showing that changing thigh size improves health," Heitmann said. She said she does not plan to do such a study, but will continue to analyze data from the original group.
More research is needed before the finding is put to medical use, Heitmann acknowledged. "If it is shown by other studies that this is not just chance but that there is a clinical relationship, this would be a good marker for increased risk over the next 10 to 12 years," she said.
"After correction for other variables, the relationship is actually very weak," Fonseca noted. "There are much better ways to predict risk, and I would not recommend that we start measuring thighs in clinic."
The impact of obesity on cardiovascular risk is described by the American Heart Association.