Fatigue levels in people with scleroderma, also known as systemic sclerosis or SSc, are tied to several social, demographic, lifestyle, and disease-related factors, according to a study by a multinational team of researchers.
Smoking, higher body mass index (BMI) — a measure of body fat based on height and weight — pain, gastrointestinal involvement, and lung disease were among the factors associated with more fatigue. In contrast, older age and male sex were linked to lower fatigue scores.
“Some factors that we have identified may be modifiable using generic interventions, including BMI and current smoking; as with any patients, people with SSc should be advised and supported to maintain a healthy lifestyle,” the researchers wrote, noting, however, that “in people with SSc, fatigue scores were substantially higher than in the general population.”
The team also called on clinicians to focus on pain when treating scleroderma patients, and seek ways to lessen its impact.
“Given the substantial association of pain with fatigue in our study, healthcare professionals should work with patients to identify aspects of [the] disease that are causing pain and attempt to address them,” the researchers wrote.
The study, “Fatigue levels and associated factors in systemic sclerosis: a cross-sectional study of 2385 SPIN Cohort participants,” was published in the journal Rheumatology.
Trying to pinpoint the causes of fatigue in scleroderma patients
SSc is characterized by the accumulation of scar tissue in the skin and internal organs, including the heart, kidneys, lungs, and digestive tract. Fatigue is a common symptom of SSc, which often has a negative impact on patients’ health-related quality of life and their ability to perform daily activities.
Now, a team of researchers from three continents — Europe, North America, and Australia — sought to learn more about the factors associated with fatigue in people with SSc.
The researchers analyzed data from 2,385 adults with SSc, enrolled between April 2014 and March 2023 from 53 sites involved in the Scleroderma Patient-centered Intervention Network (SPIN) Cohort. The cohort includes patients from seven countries.
The participants had a mean age of 54.9 and were mainly women (87%) and white people (83%). About one-third of the patients (34%) were from the U.S., 30% were from France and 22% from Canada. The remaining participants were from the U.K. (10%), and from Australia, Mexico, and Spain — a total of 4%.
Regarding disease type, 38% had diffuse SSc, characterized by widespread skin involvement and a higher risk of internal organ damage. The remaining patients had limited SSc, in which skin involvement is confined to some body areas, or sine SSc, a rare disease type with internal organ involvement but few or no skin symptoms.
Fatigue was evaluated using the Patient Reported Outcomes Information System-29 profile version 2.0 (PROMIS-29v2.0), in which higher scores indicate worse symptoms.
Fatigue levels found to be higher in SSc patients than among US population
Overall, fatigue levels were higher in people with scleroderma than in the U.S. general population (54.6 vs. 50). Still, 47% of patients — more than 1,100 — had normal fatigue levels, while 18% had mild fatigue, 27% had moderate fatigue, and 8% severe fatigue.
Lower levels of fatigue were associated with older age, being male, greater alcohol consumption, and living in France versus living in the U.S. On alcohol consumption, the study found a 0.18-point decrease in fatigue score per every weekly drink.
In contrast, smoking and higher BMI had a significant link with worse fatigue, as did living in the U.K. — also relative residing in the U.S. — and being single, divorced, or widowed.
Certain disease variables were also associated with higher fatigue scores. These were digestive involvement, digital ulcers, or sores in the fingers and toes, and joint contractures, or the inability to move a joint through its full range of motion, which results from muscles, tendons, or other tissues tightening or shortening.
A similar effect was seen in patients with rheumatoid arthritis and Sjögren’s disease as co-existing conditions with scleroderma.
Improving our understanding of fatigue, including its course over time, as well as causal and maintaining factors are important areas of future research in SSc. In addition, it is important to build the evidence base on effective interventions to manage fatigue in SSc.
In another analysis, pain intensity, itching, and interstitial lung disease, characterized by scarring in the lungs, were also associated with having worse fatigue.
“Improving our understanding of fatigue, including its course over time, as well as causal and maintaining factors are important areas of future research in SSc,” the researchers wrote. “In addition, it is important to build the evidence base on effective interventions to manage fatigue in SSc and to facilitate implementation in routine clinical care.”
As study strengths, the researchers pointed to its large multinational patient population and “the involvement of people with lived SSc experience in the study design.” As to limitations, the team noted that “participants were required to answer questions via online questionnaires, [which] may potentially reduce the generalizability of results.”