Discussion
cardiovascular disease, cognitive interference [The CPT, pain, Hypertension, hypotension, RA
VASODILATION, CARDIOVASCULAR DISEASE, DISEASE, DECAY, HYPERTENSION, EVENTS, HYPERTENSION
This study explored the acute effects of aerobic exercise on resting BP, BP responses to multiple stressful stimuli, and 24-h BP in women with RA and hypertension. Overall, a single session of aerobic exercise resulted in net PEH for SBP and reduced the SBP response to the SCWT and CPT in this population.This is the first study to assess the acute effects of exercise on BP in RA, a population with high prevalence and poor control rates of hypertension. In the present study, resting SBP remained stable from pre- to- post-exercise; however, it increased from pre- to post- control. The net decay in BP attributed to exercise accounted for the responses of control session was 5 mmHg, which represents a PEH magnitude similar to that observed in the general population [In addition to reducing resting SBP, exercise also reduced SBP reactivity to two stressful tests. The SCWT is a neuropsychological test used to assess the ability to inhibit cognitive interference [The CPT evaluates the physiological responses to pain stimulation. In the present study, the CPT test caused increases of ~18 mmHg, ~11 mmHg, and ~1 bpm on SBP, DBP and HR, respectively. Additionally, 6 participants showed increase in SBP larger than 25 mmHg, which has been associated with increase in the risks of cardiovascular events and disease [This clinical study was not designed to elucidate the specific mechanisms behind the reduction in SBP at rest and in response to stress promoted by aerobic exercise. Acute exercise-induced hypotension may be caused by sustained vasodilation of the previously active muscle and reductions in centrally-mediated sympathetic activity or in sympathetic neurovascular transduction, [Contrary to the present study hypothesis, exercise did not reduce resting DBP, DBP reactivity to SCWT and CPT, and SBP and DBP reactivity to handgrip. We cannot tell why exercise did not promote reductions in DBP to the same extent as with SBP; however this data corroborates previous studies showing that a reduction in DBP after exercise usually occur to a lesser degree than in SBP [Results of the present study provide novel information that may contribute to the management of cardiovascular disease in RA. Hypertension has been reported as one of the strongest risk factors for cardiovascular disease in RA [The present study is not without limitations. Firstly, the results of this study are limited to women with RA and multiple comorbidities and cannot be generalized to other RA subgroups. Secondly, the absence of measurements of local blood flow and vascular conductance, as well as of cardiac output and total peripheral resistance limits the understanding of the mechanisms behind the clinical responses observed in the present study. Additionally, participants’ physical activity level was assessed using a single question about their weekly amount of moderate-to-vigorous physical activity and recall bias might have affected these estimations. Another limitation was the potential carryover effect on BP across consecutive stressful tests, which may have affected the assessment of BP reactivity, specifically in the last test (i.e., handgrip test). However, 3–5 min interval between tests was employed to allow for the return of BP to baseline levels. Absence of a non-RA control group might also be considered a limitation as it prevents the assessment of the influence of RA on post-exercise BP. Finally, even though exercise promoted a PEH in SBP when compared to the responses observed in the control session, it should be noted that SBP did not decrease from pre- to post-exercise. In fact, SBP remained stable from pre- to post-exercise; therefore, the calculated PEH (i.e., 5 mmHg) was significantly influenced by the increase in SBP observed from pre-to post-control (~7 mmHg). It is not possible to draw conclusions as to why SBP increased in the control session, however prolonged time in sitting position [In conclusion, a single session of aerobic exercise reduces resting SBP and SBP reactivity to mental stress and pain. These results reinforce the role of exercise in the management of cardiovascular disease in RA, via improving the BP control in this disease.