Posted: Oct 9, 2012 8:03 PM
Oct. 9, 2012 -- Evaluating blood levels of a hormone made in the brain and the gut may help predict diseases in women, according to new research.
The researchers looked at levels of a substance called proneurotensin. It turns into neurotensin.
"Proneurotensin is the first blood biomarker ever that can independently identify elevated risk of three major disease threats to women's health," says Olle Melander, MD, PhD, professor of internal medicine at Lund University in Malmo, Sweden. He led the study.
The research is published in the Journal of the American Medical Association.
Neurotensin is released after meals, especially after eating high-fat foods. It's involved in the digestion of food, the speed at which food moves through the gut, body temperature, and pain sensation, Melander says.
More recently, he says, scientists have found it is involved in regulating appetite and feeling full. Some research suggests that neurotensin release is disturbed in obese people.
Now, Melander and others think that the hormone may also affect the risk of heart attack, other cardiovascular diseases, and breast cancer.
Melander and his team focused on men and women enrolled in the Malmo Study. It included nearly 29,000 men and women from Malmo, Sweden.
For this study, the researchers focused on 4,632 men and women who had blood levels of proneurotensin measured between 1991 and 1994.
They were then an average age of 57. The researchers followed these men and women until January 2009.
They looked to see who developed diabetes, cardiovascular diseases including heart disease and stroke, or breast cancer, and who died.
For women, but not men, higher levels of the hormone were linked with getting diabetes, breast cancer, and cardiovascular diseases, as well as dying.
Overall, the increased risk was 50% for death from cardiovascular disease and 33% for getting cardiovascular disease. But those with the highest levels had an even higher risk.
The elevated gut hormone may reflect underlying disease susceptibility, the researchers say.
They found a link or association, not a cause and effect.
In the future, finding high blood levels of the hormone may help identify ''hidden high risk'' women who don't appear to be at risk for heart disease or breast cancer, Melander says.
Why does the link hold only for women? "We do not really know," he says.
"However, studies of animal models have clearly shown that the female sex hormone estrogen stimulates the growth of cells producing neurotensin, and women obviously have a higher lifetime exposure to estrogen than men," he says.
In his research, Melander has found women have much higher levels of proneurotensin than men do. However, the process by which the hormone affects disease risk is not fully understood yet, he says.
Melander is an inventor on a patent application for using proneurotensin in disease prediction. A co-researcher is president of the company that holds those patent rights, Sphingo Tec GmbH.
"This current study will certainly stimulate further interest in neurotensin and its possible role in the pathology of human diseases," says B. Mark Evers, MD, director of the Markey Cancer Center at the University of Kentucky. He reviewed the findings.
He has studied the gut hormone and cancers for more than two decades. He is also a university professor and vice-chair of surgery, and holds the McDowell Foundation Endowed Chair.
The possibility of using a hormone as a predictive marker may offer the chance to intervene earlier and prevent diseases, he says.
Until more research is in, reducing fat in the diet might be a good step, Evers says.
The hormone is released in response to fats in the diet, he says. "Therefore, eating foods with lower fat content may decrease the release of neurotensin."