Demographic and Lifestyle Correlates of Physical Activity: The Shanghai Physical Activity Study

Background To understand the mechanisms by which physical activity influences health and to target public health recommendations, it is important to determine factors correlated with activity.

Methods We examined demographic and lifestyle factors in relation to questionnaire and accelerometer measured physical activity in 251 men and women aged 40 to 70 years in Shanghai, China. Physical activity over the past year was assessed by a newly developed questionnaire (PAQ) during two in-person interviews one year apart and by Actigraph accelerometer worn for four one-week periods over the same year. We evaluated both total physical activity energy expenditure (PAEE) and time in moderate to vigorous activity (MVPA) per day by averaging the PAQs and the four accelerometer wears, and categorizing each physical activity domain into two levels split at the median. Multiple logistic regression examined the association of demographic, anthropometric, lifestyle, and female reproductive factors reported at baseline with PAEE and MVPA as measured by PAQ and by accelerometer.

Results Over 70% of the study population achieved at least 60 minutes of average MVPA per day. In multivariate logistic regression analyses, a number of covariates were differentially associated with physical activity depending on the method of activity assessment. A high level of physical activity was less common among older men and women when measured by accelerometry, but more common when measured by self-report. In addition, while women self-reported higher PAEE, men showed suggestively higher accelerometry-assessed PAEE. Certain dietary and reproductive factors (intake of fish, fruit, and poultry; number of pregnancies) also showed distinct associations depending on method of activity assessment, although occupation, waist-hip ratio, and smoking were consistently correlated with physical activity regardless of physical activity measurement method.

Conclusion The association of physical activity with demographic, anthropometric, and lifestyle factors may vary according to method of physical activity measurement. However, these methods likely differ in the ability to capture certain domains of physical activity.