Working Out Those Prostate Proteins

PSA levels common in prostate cancer decrease with increase in physical activity

(RxWiki News) Men who like to flaunt those muscles at the gym may have another reason to keep fit and active besides looking good and feeling strong.

Exercising, even in bouts as short as one minute, can lower certain protein levels that are typically present in prostate cancer, according to a recently published study.

The findings could eventually show how physical activity directly affects the risk of developing prostate cancer, researchers said.

"Get up, get exercising!"

The aim of the study, by Paul Loprinzi, PhD, and Manish Kohli, MD, from the Department of Exercise Science at Bellarmine University and the Division of Medical Oncology in the Department of Oncology at Mayo Clinic, was to investigate the links between physical activity, or lack thereof, and prostate-specific antigen (PSA).

PSA is a protein produced by the prostate gland. Too much of it could indicate that a man may have prostate cancer.

Researchers pulled data from more than 1,600 men in the 2003-2004 and 2005-2006 National Health and Nutrition Examination Survey, which collects information on a number of health topics.

Researchers measured participants' level of physical activity for one week using an accelerometer, which measures how long, intense and often a person exercises.

Each participant wore the device on his hip throughout the day except while sleeping or doing water-based activities. Moderate and vigorous activities were grouped together since little time was spent in the latter.

Researchers kept track of patients' body mass index, which calculates their height and weight together, as well as their age, ethnic background, education level and marital status.

They also recorded patients' food, alcohol and medicine intake. Among the participants, a little more than 48 percent exercised in 1-minute bouts and about 10 percent exercised in 10-minute bouts.

Researchers found that, with every extra hour of being sedentary, the men were 16 percent more likely to have higher levels of PSA.

On the opposite end, participants were 18 percent less likely to have elevated PSA concentrations with each one-hour increase in light physical activity.

"It is possible that the underlying mechanism delineating the association between physical activity and PSA concentration is through physical activity-induced changes in testosterone levels…," researchers wrote in their report.

"In addition to the observed association between light activity and lower PSA concentration, more sedentary behavior was associated with higher PSA concentration."

PSA concentrations were significantly lower among participants who met physical activity guidelines compared to those who didn't.

Researchers said that the ties between being sedentary, general health and PSA concentration are "still in its infancy" and need further study.

The study was published in the January 13 issue of the journal Mayo Clinic Proceedings. Funding information and conflicts of interest were unavailable.

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Review Date: 
January 13, 2013