Background: Autonomic dysfunction and inflammatory activity are involved in the development
and progression of coronary artery disease (CAD), and exercise training has been
shown to confer a cardiovascular benefit. Objective: To evaluate the effects that interval training (IT) based on ventilatory
anaerobic threshold (VAT) has on heart rate variability (HRV) and high-sensitivity
C-reactive protein (hs-CRP) levels, as well as the relationship between both
levels, in patients with CAD and/or cardiovascular risk factors (RF). Method: Forty-two men (aged 57.88±6.20 years) were divided into two training groups,
CAD-T (n= 12) and RF-T (n= 10), and two control groups, CAD-C (n= 10) and RF-C
(n=10). Heart rate and RR intervals in the supine position, cardiopulmonary
exercise tests, and hs-CRP levels were measured before and after IT. HRV was
analyzed by spectral and symbolic analysis. The CAD-T and RF-T underwent a 16-week
IT program of three weekly sessions at training intensities based on the VAT. Results: In the RF-T, cardiac sympathetic modulation index and hs-CRP decreased
(p<0.02), while cardiac parasympathetic modulation index increased (p<0.02).
In the CAD-T, cardiac parasympathetic modulation index increased, while hs-CRP,
systolic, and diastolic blood pressures decreased (p<0.02). Both control groups
showed increase in hs-CRP parameters (p<0.02). There was a strong and
significant association between parasympathetic and sympathetic modulations with
hs-CRP. Conclusion: The IT program based on the VAT promoted a decrease in hs-CRP associated with
improvement in cardiac autonomic modulation.