Evidence for aerobic insufficiency in women with systemic lupus erythematosus

Abstract

Objective. To determine if fatigue is associated with diminished aerobic capacity in women with systemic lupus erythematosus (SLE). Methods. Eighteen women (age 35 ؎ 9 years) with mild SLE (Systemic Lupus Activity Measure ‫؍‬ 3.1 ؎ 2.1) and 16 healthy but sedentary controls (age 38 ؎ 8 years) completed peak treadmill exercise tests to determine aerobic capacity and Fatigue Severity Scales to quantify the severity of fatigue. Measures of oxygen consumption (VO 2 ) were recorded during the treadmill tests. Results. Peak VO 2 was lower in patients with SLE (19.2 ؎ 4.4 ml/kg/minute) as compared with controls (27.4 ؎ 4.7 ml/kg/minute) and expected values (30.7 ؎ 3.1 ml/kg/minute; P < 0.0006 versus controls and P < 0.0001 versus expected). Functional aerobic impairment was observed in 14 of the 18 patients with SLE. In patients with SLE, ventilatory threshold, a marker for the onset of lactic acidemia, was observed at the lowest energy requirement for instrumental activities of daily living. Peak VO 2 in the patients with SLE was similar to the highest energy requirements for instrumental activities of daily living, leaving little or no reserve for more intense occupational and recreational activities. Peak VO 2 was significantly higher (P < 0.0001) than the activity of daily living requirements in controls, providing a substantial energy reserve. Fatigue severity score (FSS) was 5.0 ؎ 1.4 in patients with SLE, with 14 of the 18 patients having scores above 4.0, a score indicating that fatigue severity limited physical activity. Of the 14, 12 had functional aerobic impairment. An FSS of greater than 4.0 was not observed in controls (mean ‫؍‬ 2.5 ؎ 0.7). Conclusion. In women with SLE, aerobic capacity was diminished to levels that were insufficient for engaging in activities of daily living and below those expected to result from physiologic deconditioning. This functional aerobic impairment was strongly correlated with the perception of severe, activity-limiting fatigue.

Oxidative stress and fatigue in systemic lupus erythematosus

“…Aerobic capacity is reduced to a level that is inadequate for avoiding fatigue while engaging in routine daily tasks. 8 However, the molecular mechanisms underlying reduced aerobic capacity are not understood. There is little data regarding the physiologic basis for the abnormal cardio-respiratory response and diminished exercise tolerance demonstrated by SLE subjects.…”

Reliability and validity of the Fatigue Severity Scale in Swedish for patients with systemic lupus erythematosus

“…It is reported in 50-90% of patients with SLE (5-8) and such patients reportedly have more fatigue than healthy people do (9)(10)(11)(12)(13)(14). As fatigue influences quality of life (13), it is an important variable to assess in treatment interventions.…”

Impaired Aerobic Capacity in Systemic Lupus Erythematosus Patients: What are the Physiological Mechanisms

“…There is a growing body of evidence indicating impaired aerobic capacity in SLE patients [4][5][6][7]. For instance, Keyser et al [5] Additionally, Robb-Nicholson et al [18] showed that SLE patients performed at 45% of expected VO 2max , while Tench et al [19] concluded that SLE women exhibited poor exercise capacity, having a VO 2max 62% of the average expected value in healthy females of the same age (normality>85% VO 2max predicted) ( Furthermore, in a more recent study on childhood-onset SLE, Prado et al [22] observed both lower exercise tolerance and aerobic capacity when compared with healthy control children.…”

“…For instance, Keyser et al [5] Additionally, Robb-Nicholson et al [18] showed that SLE patients performed at 45% of expected VO 2max , while Tench et al [19] concluded that SLE women exhibited poor exercise capacity, having a VO 2max 62% of the average expected value in healthy females of the same age (normality>85% VO 2max predicted) ( Furthermore, in a more recent study on childhood-onset SLE, Prado et al [22] observed both lower exercise tolerance and aerobic capacity when compared with healthy control children. Taken together, these findings suggest that the aerobic capacity impairment observed in SLE patients may be associated with a reduced capacity to engage in both daily occupational activities and recreational tasks.…”

“…Although its pathogenesis is believed to lie in the dysregulation of the immune system, the involvement of various organ systems often leads to secondary comorbidities resulting from renal failure, hypertension, and central nervous system disorders [2]. Furthermore, SLE patients can present limitations in exercise capacity and reduced quality of life due to various clinical conditions such as fatigue, cardiorespiratory disease and muscle involvement [3][4][5][6]. In this sense, the ability to sustain daily physical activities is inextricably linked to the integrity of the oxygen (O 2 ) transport pathway, which in turn depends on several multi-organ interactions involving the heart and vessels, lungs, respiratory/peripheral muscles and autonomic nervous systems [7].…”