Anti-TNF alpha therapy is able to significantly restore ankylosing spondylitis patients’ capacity to exercise after a treatment period of four months, a small study suggests.
After treatment, patients in the study improved in objective measures of cardiorespiratory fitness, such as peak oxygen uptake during exercise, maximum work rate, and duration of exercise.
The study, “A prospective clinical investigation of the effects of anti-TNF alpha therapy on exercise capacity in patients with ankylosing spondylitis,” was published in the Turkish Journal of Medical Sciences.
Although ankylosing spondylitis (AS) is a chronic inflammatory disease affecting mainly the spine and hip joints, some patients may develop other symptoms such as heart and lung problems, which can affect patients’ physical ability, tolerance to exercise, and quality of life.
Anti-tumor necrosis factor (TNF) alpha therapy is currently the treatment of choice for reducing disease activity and relieving AS symptoms. It also substantially improves physical function and quality of life, according to patient-reported assessments. However, self-assessment tests depend on patients’ subjective evaluation and do not provide an objective measurement of treatment response.
Therefore, researchers at the Karadeniz Technical University in Turkey decided to investigate in a reliable and objective manner the effects of anti-TNF alpha therapy on the exercise capacity of AS patients using cardiopulmonary exercise testing (CPET).
CPET is non-invasive and widely used to evaluate an individual’s exercise capacity and limit, something that cannot be determined clinically and may be less evident at rest. The test consists of measuring cardiorespiratory variables, including oxygen uptake (VO2), along with electrocardiography (ECG), blood pressure, and pulse oximetry (to measure oxygen levels in the blood). The assessment is done while a person exercises at a gradually increasing workload, until his or her maximum capacity.
The study compared the exercise capacity of 28 AS patients before and after a four-month treatment with anti-TNF alpha therapy. An equivalent number of healthy individuals were included as controls, and were matched to patients by age, sex, body mass index (BMI), and smoking status.
All patients had active disease (BASDAI score of four or above) and had never been on anti-TNF agents. Most patients (57.1%) used infliximab (trade names Inflectra, Remicade, Renflexis, and Flixabi), followed by 25% who used etanercept (Enbrel, Erelzi, and Brenzys), and 17.9% who used adalimumab (Humira). The mean duration of disease was 8.9 years.
A bicycle ergometer was used for the CPET. As expected, patients with AS exhibited significantly lower aerobic exercise capacity than healthy controls at the beginning of the study. However, patients significantly improved their objective exercise capacity, determined by CPET, after four months of anti-TNF alpha therapy. Aerobic capacity (measured by peak VO2), maximum work rate, and duration of exercise were significantly improved, getting closer to healthy levels.
“Our study showed a marked and rapid objective improvement in exercise capacity following anti-TNF alpha therapy,” the researchers wrote.
Significantly, anti-TNF alpha treatment reduced inflammation, as assessed by CRP and ESR blood tests. It also lowered disease activity, and improved the functional ability and spinal mobility of patients, as measured by BASDAI, BASFI, and BASMI scores. Patients also reported an improvement in quality of life on the ASQoL questionnaire.
Therefore, in addition to controlling disease activity and improving quality of life, short-term anti-TNF alpha therapy can considerably improve the cardiopulmonary health and fitness of AS patients.
“These findings may represent an additional and concrete justification for (a patient’s) transition to anti-TNF alpha therapy,” the researchers concluded.