Arterial stiffness, inflammation, fitness and psychological stress in women with systemic lupus erythematosusrole of physical activity and aerobic exercise

Resumo

Systemic lupus erythematosus (SLE) is an autoimmune disease of unknown etiology that predominantly affects young adult women. SLE represents a heavy burden for the health care system. Identifying factors associated with lower symptomatology and disease severity is of clinical and public health interest. The major aims of this Doctoral Thesis were: to examine the association of physical activity levels, assessed by accelerometry, with arterial stiffness in women with SLE, as well as to explore whether women meeting the physical activity guidelines of the American College of Sport Medicine have lower arterial stiffness than those not meeting these recommendations; to evaluate the association of physical activity intensity levels, measured with accelerometry, and sedentary time with psychological stress in women with SLE; and to show the effect of 12-week aerobic exercise on arterial stiffness (primary outcome), inflammation, oxidative stress and cardiorespiratory fitness (secondary outcomes) in women with SLE. To address these aims, three studies were conducted in the context of two projects. Project I (Studies I and II). Forty-seven women with SLE were included in both studies, where physical activity and sedentary time were measured by triaxial accelerometry. Arterial stiffness was obtained by measuring the pulse wave velocity (PWV) using the device Mobil-O-Graph® 24h pulse wave monitor and psychological stress was recorded using the perceived stress scale. Project II (Study III). A total of fifty eight women with SLE were included and assigned to a group that performed supervised aerobic exercise on treadmill for 12 weeks (n=26) or to a control group that received healthy lifestyle recommendationsto (n=32). Arterial stiffness was assessed by PWV using the Mobil-O-Graph® 24h device. Ultrasensitive serum CRP was evaluated by an immunoturbidimetric method using the ARCHITECT cSystems. Interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α), as well as myeloperoxidase (MPO; as marker of oxidative stress), were measured by immunoradioassay using commercial kits and following the manufacturer's instructions. Cardiorespiratory fitness was assessed with the Bruce protocol. The main findings of this Thesis indicate that: I) Physical activity levels and sedentary time are not associated with arterial stiffness in women; II) Lower levels of moderate physical activity or moderate-to-vigorous physical activity are associated with higher psychological stress in women with SLE. Women who did not meet the international physical activity guidelines presented higher psychological stress than those meeting them; and III) 12 weeks of progressive treadmill aerobic exercise following the American College of Sport Medicine guidelines increases cardiorespiratory fitness without exacerbating arterial stiffness, inflammation, or oxidative stress in women with SLE, in comparison to the control group. The results of this Doctoral Thesis enhance our understanding about the association of physical activity/physical exercise and sedentary time with key symptoms of SLE, such as arterial stiffness, psychological stress, inflammation and cardiorespiratory fitness. These results will help to generate future studies that evaluate the preventive and therapeutic value of physical activity/physical exercise in this population.