Physical frailty in patients with systemic sclerosis

Systemic sclerosis (SSc) is a chronic disease characterized by autoimmunity, vasculopathy and fibrosis of several organs, such as skin, lungs, and heart. During the disease course, patients with SSc are prone to accumulating multiple organ damage and increasing their vulnerability to adverse outcomes. This increased vulnerability to adverse outcomes when exposed to a stressor among people of the same age is known as frailty. One of the most used definitions of frailty is the physical frailty phenotype (PFP), including 5 components: unintentional weight loss, exhaustion, muscle weakness, slow walking speed, and low physical activity. There is scarce data about frailty in patients with SSc.

To determine the prevalence and clinical profile of PFP in a sample of patients with SSc. To investigate the diagnostic accuracy of the Fatigue, Resistance, Ambulation, Illness and Loss of weight (FRAIL) scale, Edmonton frailty scale (EFS) and Short Physical Performance Battery (SPPB) using the PFP as the reference standard.

Cross-sectional study including 94 patients with SSc according to the 2013 ACR-EULAR classification criteria or the criteria suggested by Le Roy and Medsger for early disease. Gastrointestinal symptoms were assessed by the UCLA GIT 2.0 questionnaire, malnutrition was defined according to European Society of Clinical Nutrition and Metabolism (ESPEN) recommendations, and physical performance was assessed by SPPB. PFP assessment was according to the original definition, except for physical activity domain, assessed with the International Physical Activity Questionnaire (IPAQ). FRAIL scale and EFS were also applied to the same individuals. For diagnostic assessment of FRAIL, EFS and SPPB, we estimated the area under the receiver operating characteristic curve (AUC), considering PFP as the reference standard and dichotomizing the results in frail vs. non-frail.

According to PFP, 33 patients (35.1%) were considered frail and 53 patients (56.4%) pre-frail. According to FRAIL scale, 27 patients (28.7%) were considered frail and 53 patients (56.4%) pre-frail. According to EFS, 28 patients (29.7%) were classified as vulnerable and 15 (15.9%) as frail: mild in 8 (8.5%), moderate in 5 (5.3%) and severe in 2 (2.1%). According to SPPB, 19 patients (20.2%) were considered frail. The AUC against PFP was: 0.829 (95% CI 0.743-0.916) for FRAIL scale, 0.859 (95% CI 0.784-0.934) for EFS and 0.791 (95% CI 0.697-0.885) for SPPB. The PFP was associated with current use of glucocorticoids (p=0.011), UCLA GIT 2.0 score (p=0.001), HAQ (p<0.0001), patient and physician-assigned VAS (p<0.0001, both), malnutrition (p=0.007), hospitalizations in the past year (p=0.008) and dependence on BADL and IADL (p=0.027 and p<0.0001, respectively). The PFP was not associated with gender (p=0.679), age (p=0.303), disease duration (p=0.504), Rodnan skin score (p=0.918), diffuse subtype (p=0.116), polypharmacy (p=845) and sarcopenia (p=0.328).

Frailty is prevalent in patients with long-standing SSc and is associated with disability, limitations in daily activities and hospitalizations in the past year. Also, malnutrition and more severe gastrointestinal symptoms were more common in frail patients. Both FRAIL scale and EFS showed excellent diagnostic accuracy against PFP as the reference standard, however the FRAIL scale presents a higher sensitivity and seems to be more feasible and practical than EFS and SPPB in clinical practice.