Relationship between occupational physical activity and subclinical vascular damage in moderate-altitude dwellers

Background: Occupational physical activity (OPA) has been associated with increased cardiovascular events. The aim of this study was to investigate the association between OPA and markers of subclinical vascular damage among a moderate-altitude population living in the rural village of Chauricharka (Nepal 2600 m s.l.). Methods: Seventy-two individuals (age 42±15yrs, 15-85, 23 men) were enrolled. Physical activity was evaluated using the international physical activity questionnaire (IPAQ). Carotid-femoral pulse wave velocity (PWV), carotid ultrasound assessment and flow mediated dilation (FMD) were performed. Results: OPA was 9860±5385 MET-minutes/week, representing 77% of total energy expenditure, with 97% of the population performing high-intensity physical activity. In the univariate analysis OPA was significantly associated with PWV (β =0.474, p=0.001) and carotid stiffness (CS) (β =0.29, p=0.019). In the multivariate analysis, including age, sex, oxygen saturation, mean blood pressure, LDL and OPA, OPA remained an independent predictor of PWV (β=0.403, p=0.001) but not of CS (β =0.028, p=0.8). OPA remained an independent predictor of PWV independently from Framingham risk score. Conclusion: High-intensity OPA shows a positive, independent association with aortic stiffness in Himalayan moderate-altitude dwellers. This study suggests how vigorous OPA performed in moderate- altitude may be a cardiovascular risk factor.