Exercise as it relates to Disease/Exercise Training to reduce the risk of Cardiovascular Disease associated with Systemic Lupus Erythematosus

The following is a critique of the paper “Using Exercise Training to Counterbalance Chronotropic Incompetence and Delayed Heart Rate Recovery in Systemic Lupus Erythematosus: A Randomised Trial”, researched by Miossi et al (2012).

Background to research
Explanation of Systemic Lupus Erythematosus Systemic Lupus Erythematosus (SLE) is a chronic autoimmune disorder, occurring when there is an over-production of antibodies (immune cells) that attack the body’s healthy tissues without provocation causing inflammation. SLE affects individuals differently and with varying degrees of severity, ranging from manageable symptoms to severe conditions. Pathology can vary substantially between individuals as a result of multi-system inflammation, thus presenting various signs and symptoms. Prevalence SLE affects approximately over five million individuals worldwide, with a predicted 16,000 new cases each year. SLE is nine times more likely to occur in females than males and is more prevalent in non-Caucasian populations, with onset of symptoms typically occurring during puberty. Relation to cardiovascular diseases Due to systemic inflammation occurring in individuals with SLE, cardiovascular function has an increased risk of impairment. Therefore, SLE is an identified risk factor for cardiovascular events and increased mortality. Chronotropic incompetence is a cardiovascular condition occurring when the heart is unable to increase in function (i.e. increasing heart rate or blood pressure), in relation to the workload it’s undergoing. Associatively, delayed heart rate recovery refers to the time the heart takes to return to its resting function after stress. The importance of addressing chronotropic incompetence and delayed heart rate recovery is due to their nature as cardiovascular predictors of mortality and its prevalence in SLE populations.

Where is the research from?
The authors; R. Miossi, F. Lima and E. Borba have extensive academic history investigating various areas in immunology and SLE. The critiqued study’s findings are considered reputable as published in the journal of Arthritis Care and Research, an official journal of the American College of Rheumatology.

What kind of research?
The study conducted by Miossi et al. was a randomised control trial lasting three months, proposing a non-pharmaceutical intervention to improve chronotropic incompetence and delayed heart rate recovery in SLE patients. The study’s participants had SLE but were in a healthy state. Their symptoms were mild as required by the study’s parameters.

What did the research involve?
The study was conducted over 12 weeks. 30 inactive females with SLE (aged 20 – 40 years), were randomly assigned to two groups: training (n=15) versus non-training (n=15). A healthy control group matched the parameters of the test group. Every participant was assessed prior to the intervention and again at 12-weeks, with a principal focus upon chronotropic reserve (CR), heart rate (HR) and heart rate recovery (HRR). The pre and final study measures were taken during a maximal cardiovascular graded exercise protocol. Participants had to meet certain inclusion and exclusion criteria prior to participating in the study, for example, having no prior cardiovascular issues. Additional to meeting the American College of Rheumatology criteria for SLE, participants were required to have a disease activity, as outlined by the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) of four or less. The exclusion criteria outlined for this study was comprehensive, referencing various symptoms associated with SLE (reference) that may impact the study and welfare of the participants. The exercising SLE group and the control group underwent a moderate-intensity supervised exercise program twice a week for 12-weeks. The program was as follows Accumulating a total of 75-80 minutes, twice a week for 12 weeks.
 * 1) 5 minutes warm up
 * 2) 35-40 minutes of resistance training
 * 3) 30 minutes of aerobic exercise; performed on a treadmill
 * 4) 5 minutes stretching

What were the basic results?
The three-month exercise-training program stimulated an improvement in chronotropic incompetence and delayed HRR in physically inactive SLE patients. Successfully supporting the objective of the study without exacerbating any disease process or symptoms. The exercising SLE participants attained levels of cardiac function that were comparative to the healthy control group.

What were the conclusions?
In summary, the three-month exercise intervention was successful in improving chronotropic incompetence and delayed heart rate recovery in SLE participants. The researchers disclosed their uncertainty regarding the mechanisms associated with the improvement in cardiovascular function but consider a relationship with the autonomic nervous system. It is proposed that exercise causes a suppression of Angiotensin II (a hormone), causing an increase in the heart’s function, therefore increasing the heart’s functionality under stress. The researchers have over promoted the success of their findings. Firstly, the SLEDAI criteria utilised by the study, classifies a range of pathologies at varying scores that may underestimate the effect of potential symptoms (i.e. arthritis) upon participants. As SLE is a dynamic disease process from which individuals can experience flare-ups and remissions, Miossi et al. have limited the study to a very specific cohort. Lastly, this study focused solely upon females, and neglects to identify the ethnicity of the testing population. Therefore, despite Miossi et al. successfully proving the advantageous nature of an exercise intervention, the data cannot be accurately generalised to a broader population of interest.

Practical advice
Substantial evidence concretes the notion that exercise has a positive effect upon cardiovascular conditions, reducing mortality risk. However, the exercise program prescribed does not meet the World Health Organisation physical activity guidelines of 150 minutes of moderate-intensity aerobic physical activity. Nonetheless, supporting the notion that some volume of exercise is beneficial, and should not be negated due to volume differences. Further consideration should be applied to the progression and maintenance of the improvements stemming from the exercise program. The benefits of a moderate-intensity exercise program can be clearly seen to reduce mortality risk, dependent upon improving cardiovascular function. Note that chronotropic incompetence is a small part of total cardiovascular pathology, and this intervention does not provide a total ‘cure’.

Further information and resources
For further information regarding Systemic Lupus Erythematosus please visit the Australasian Society of Clinical Immunology and Allergy website or the Victorian Better Health: Lupus website.