Physical Activity Levels Studied in China for Impact on Cancer Risk

Division of Cancer Epidemiology and Cancer Genetics

A growing body of evidence demonstrates that the level of physical activity (PA) may be related to the risk of certain cancers. Most of these studies have been conducted in developed, urbanized Western societies, including the United States, but little is known about PA levels in China and other developing nations which are rapidly “westernizing” their economies and lifestyles.

To address this knowledge gap, researchers from NCI’s DCEG have joined with scientists from Vanderbilt University and the Shanghai Cancer Institute to assess PA levels in the city of Shanghai, China. They are also studying how the PA habits of Chinese adults affect the blood plasma levels of certain inflammatory biomarkers associated with increased cancer risk.

Steven C. Moore, Ph.D., a research fellow in DCEG’s Nutritional Epidemiology Branch noted, “We had epidemiologic research ongoing within Shanghai already, so we decided to monitor the PA of a subset of study participants using devices that measure motion, known as accelerometers.” The accelerometers provide researchers a minute-by-minute assessment of a participant’s physical activity. “Such data will allow us to examine PA at different intensity levels among men and women living in Shanghai and whether their PA levels are comparable to those of men and women in the United States,” he added.

The researchers conducted their studies among subsets (300 individuals each) of healthy adults from the Shanghai Women’s Cohort and Shanghai Men’s Cohort. In previous work among these populations, self-reported data on PA levels suggested that Shanghai women engaged in much more physical activity than U.S. women, Dr. Moore said. Moreover, contrary to what has been found in the United States, older and/or heavier Shanghai residents reported a greater level of PA than younger and/or lighter individuals.

Intrigued, the researchers took a closer look using a specially-designed PA questionnaire and the accelerometers, which each of the study participants wore for a full week, once every three months during the year-long study period. “One of our study goals was to develop a PA questionnaire that is culturally appropriate to China, so that we could better understand patterns of physical activity there,” Dr Moore explained. “We developed a questionnaire that emphasizes participation in everyday routine activities, such as light household work and activity as part of an occupation. We also included much greater representation of those exercise activities that are common among Shanghai residents.” The researchers validated this questionnaire against the objective accelerometer data and their initial analysis has been submitted for publication to a peer-reviewed medical journal.

The scientists also collected blood and urine samples from the study subjects to determine the levels of several biomarkers related to chronic low-grade inflammation and also to cancer risk. The researchers will analyze whether different types and intensities of physical activity, measured objectively by the accelerometers, are associated with circulating levels of these inflammation markers. The researchers will also analyze the bio-samples for potential biomarkers of short-term and long-term PA levels.