Physical activity (PA) is a preventative behavior for noncommunicable disease. However, little consideration is given as to whether different domains of PA have differing associations with health outcomes. We sought to determine the association between occupational, sport, leisure, and total PA with baroreflex sensitivity (BRS), distinguishing between neural (nBRS) and mechanical (mBRS) BRS. In a cross-sectional analysis of 8649 adults aged 50 to 75 years, resting nBRS (estimated by low-frequency gain, from carotid distension rate and heart rate) and mBRS (carotid stiffness) were measured by high-precision carotid echo-tracking. PA was self-reported using the validated Baecke questionnaire. The associations between PA and nBRS and mBRS were quantified using multivariate linear regression analysis, separately in the working and nonworking population. In working adults (n=5039), occupational PA was associated with worse nBRS (unstandardized β=-0.02; [95% CI, -0.04 to -0.003]; P=0.022) whereas sport PA was associated with better nBRS (β=0.04; [95% CI, 0.02-0.07]; P=0.003) and mBRS (β=-0.05; [95% CI, -0.09 to -0.00001]; P=0.049). Neither leisure PA nor total PA was associated with nBRS or mBRS. In nonworking adults (n=3610), sport PA and total PA were associated with better mBRS (β=-0.08; [95% CI, -0.15 to 0.02]; P=0.012 and β=-0.05; [95% CI, -0.10 to 0.009]; P=0.018) but not nBRS. These findings suggest differential associations between domains of PA and BRS and may provide insights into the mechanisms underlying the association between occupational PA and cardiovascular disease.
Keywords: association; blood pressure; cardiovascular disease; exercise; hypertension.