Sex influence on outcomes of patients with systemic sclerosis-associated interstitial lung disease: an EUSTAR database analysis

OBJECTIVE Interstitial lung disease (ILD) is the leading cause of morbidity/mortality in systemic sclerosis (SSc). We aimed to study investigate the impact of sex on SSc-ILD. METHODS EUSTAR SSc patients with radiological-confirmed ILD and available %predicted forced vital capacity(%pFVC) were included. Demographics and disease features were recorded. Change in %pFVC over 12±6 months (cohort 1) was classified into stable (≤4%), mild (5-9%) and large progression (≥10%). In those with 2-year longitudinal %pFVC (cohort 2), %pFVC change at each 12±6 months interval was calculated. Logistic regression analyses (OR and 95%CI) and Cox proportional hazards models adjusted for age and %pFVC were applied. RESULTS 1136 male and 5253 female SSc-ILD patients were identified. Males were significantly younger, had a shorter disease duration, higher prevalence of CRP elevation, were had frequently a diffuse cutaneous involvement. In cohort 1(1655 females and 390 males), a higher percentage of males had stable ILD (74.4% versus 69.4%, p = 0.056). In multivariable analysis, disease duration and %pFVC(OR 0.99,0.98-0.99; 0.97,0.95-0.99) in males and age, %pFVC and anti-centromere(OR 1.02,1.00-1.04; 0.97,0.96-0.98; 0.39,0.245-0.63) in females were associated with large progression. The 1-year mortality rate was higher in males (5.1% versus 2.5%, p = 0.013). In cohort 2(849 females and 209 males), a higher percentage of females showed periods of large progression (11.7% versus 7.7%, p = 0.023), the percentage of patients with 0, 1 or 2 periods of worsening was not different. The overall death rate was 30.9% for males and 20.4% in females (p < 0.001). At survival analysis, male sex was a predictor of mortality (OR 1.95, 1.66-2.28). CONCLUSIONS Male SSc-ILD patients have a poorer prognosis and sex-specific predictors exist in SSc-ILD