Objective: To measure self-reported physical and mental functioning and associated clinical features at study entry in 3 ethnic groups with systemic sclerosis (SSc).
Methods: Sixty Hispanic, 39 African American, and 104 Caucasian patients with recent-onset SSc (< 5 yrs) were assessed for perceived physical and mental functioning, using the Medical Outcomes Study Short Form-36 (SF-36) and Scleroderma-Health Assessment Questionnaire (Scleroderma-HAQ). Socioeconomic, demographic, clinical, immunologic, immunogenetic, behavioral, and psychological variables (Interpersonal Support Evaluation List, ISEL; Illness Behavior Questionnaire, IBQ; and Arthritis Helplessness Index, AHI) were analyzed by linear regression models for associations with SF-36 and mHAQ scores as dependent variables.
Results: Perceived physical functioning scores had ethnic-specific associations with AHI > fatigue scores > IBQ > clinical variables (hypertension, skin score, and percentage predicted DLCO). Scleroderma-HAQ scores had ethnic-specific associations with IBQ > AHI scores > most clinical and laboratory variables. Decreased mental component summary (MCS) scores associated with AHI > ISEL. Ethnic-specific immunogenetic variables HLA-DQB1*0202 (Caucasian) and HLA-DRB 1*11 (African American), and HLA-DQA1*0501 (Hispanic) also associated with MCS. Antinuclear autoantibodies, anti-topoisomerase I, and RNA polymerases I and III also demonstrated associations with functioning in African American and Hispanic groups.
Conclusion: Clinical, psychosocial, and immunogenetic variables had ethnic-specific associations with perceived physical and mental functioning. Consideration of ethnic-specific psychological and behavioral support in designing more personalized, relevant therapeutic interventions for the patient may improve therapeutic efficacy in SSc.