Independent association between occupational exposure and decline of forced vital capacity in systemic sclerosis (SSc): a multicenter recruitment retrospective cohort study.

Abstract Background Although male sex is associated with poor prognosis in Systemic Sclerosis (SSc), it is unclear whether this association is independent of confounding factors such as occupational exposure to toxicants. Research Question What is the respective impact of sex and occupational exposure on SSc patients’ characteristics with a focus on lung function decline? Study Design and Methods Patients with SSc (n=210, 55 males) underwent standardized quantitative assessment of occupational exposure through a cumulative exposure score (CES) in a multicenter recruitment retrospective cohort. Association of the CES with patients’ characteristics was assessed. Mixed linear, logistic and Cox regression models were used to identify predictors of time variation of forced vital capacity (FVC) and the hemoglobin-corrected transfer coefficient for carbon monoxide in the lung (DLCOc). Results Male sex was strongly associated with occupational exposure (OR=10.3, p Interpretation Occupational exposure to toxicants appears to independently predict decline of FVC in SSc patients, regardless of sex. Assessment of occupational exposure may be useful for SSc prognostication.