Author(s): VAARA, J.P., VASANKARI, T., RAITANEN, J., KYRÖLÄINEN, H., Institution: NATIONAL DEFENCE UNIVERSITY, Country: FINLAND, Abstract-ID: 1913

INTRODUCTION:
Physical activity has been shown to have anti-inflammatory effects, which could counteract the increased risk regarding low-grade inflammation (Pedersen 2006) and its risk for future cardiovascular diseases. The purpose of the present study was to investigate the association of device based physical activity and physical fitness, including both cardiorespiratory and muscular fitness with selected inflammatory factors in young adult men.
METHODS:
The study sample consisted of 415 participants with inclusion criteria as a minimum of four days with ≥10 hours wear time per day. Participants were 776 young (age mean:26, sd:7 yrs.) adult Finnish men, who were invited in the military refresher training. A waist-worn triaxial accelerometer (Hookie AM 20, Traxmeet Ltd, Espoo, Finland) was used to assess physical activity and sedentary time. Physical activity was stratified into three intensity categories regarding METs: light physical activity 1.5–2.9 MET; moderate physical activity 3.0–5.9 MET and vigorous physical activity ≥ 6.0 MET. Cardiorespiratory fitness (VO2max) was determined using an indirect graded cycle ergometer test until exhaustion. Muscular fitness tests consisted of push-ups, sit-ups, standing long jump and maximal isometric force of the lower and upper extremities. Muscular fitness index was calculated firstly converting muscular fitness test results to z-scores. Thereafter, these z-scores were summed together and then standardized as a final composition of muscular fitness index. Inflammatory factors (interleukin-6 [IL-6], C-reactive protein [CRP], adiponectin, fibrinogen and leptin) were analyzed from blood samples. Linear regressions were used to calculate β-coefficients with Holm-Bonferroni correction.
RESULTS:
Sedentary time was positively and vigorous physical activity inversely related to IL-6 (β:0.10, β:-0.10, respectively) (p<0.05) and leptin (β:0.15, β:-0.20, respectively) (p<0.05). Light and moderate activity were inversely related to leptin only (β:-0.11, β:-0.13, respectively) (p<0.05). Neither sedentary nor physical activity were related to with adiponectin, fibrinogen and CRP. Aerobic fitness was inversely related to IL-6 (β:-0.21), leptin (β:-0.69), adiponectin (β:0.11), fibrinogen (β:-0.26) and CRP (β:-0.47), while muscular fitness index was related to IL-6 (β:-0.14), leptin (β:-0.45), fibrinogen (β:-0.17) and CRP (β:-0.34) but not to adiponectin.
CONCLUSION:
Physical fitness was related to most of the inflammatory factors, while physical activity and sedentary time were only related to selected inflammatory factors. IL-6 and leptin had the most consistent relationship to both physical activity and physical fitness. Physical activity itself, and in particular vigorous physical activity that improves physical fitness, may improve low-grade inflammation as assessed by certain inflammatory biomarkers.