Cigarette smoking is not a risk factor for systemic sclerosis

Abstract

Background The role of cigarette exposure in susceptibility to systemic sclerosis (SSc) has not been previously studied. Our objective was to investigate the association of smoking with susceptibility to SSc in a large well-defined patient population. Methods We conducted a review of 1,379 SSc patients enrolled in the Scleroderma Family Registry and DNA Repository and/or the Genetics versus Environment in Scleroderma Outcome Study (GENISOS) cohort. Smoking history was obtained from chart review or via telephone interview. SSc patients were subsequently categorized as never smokers or ever smokers. SSc patients with available smoking data were matched 2:1 by age, gender, ethnicity and state of residence to controls using the Behavioral Risk Factor Surveillance System. Results The majority of cases were White (74.2%) with Latinos and Blacks representing 11.3% and 9.7%, respectively. Most patients had limited disease type (54%). For our comparative analyses, 621 patients were matched to controls. There was no significant difference in age, gender, ethnicity and SSc disease type between matched versus unmatched patients. The majority of patients had never smoked (57%), while 43% of patients were ever smokers. The SSc patients did not differ in their smoking behavior from controls (p=0.842, OR: 1.020, 95% CI: 0.839–1.240). Anti-topoisomerase positive patients were more likely to be never smokers (p=0.049, OR=0.648, 95% CI=0.421–0.998) whereas no such association was found with the anti-centromere and anti-RNA Polymerase antibodies. Conclusion Unlike in rheumatoid arthritis, smoking does not confer a risk for development of SSc, though it may impact disease severity.

Environmental risk factors of systemic sclerosis

“…A recent series has demonstrated that diesel exhaust nanoparticles induced, in vitro, (1) higher mRNA gene expression of metalloproteases 2, 7, 9, and 12; collagen I and III; and vascular endothelial growth factor (VEGF) in SSc fibroblasts than in controls and (2) activation of keratinocytes of patients with diffuse cutaneous SSc with increase of pro-fibrotic cytokines: IL-1α, IL-8, and IL-6 mRNA levels [73]. IL-1α has been reported to be greatly increased in SSc epidermis, and it is speculated to initiate keratinocyte-fibroblast interactions, leading to fibroblast activation [74].…”

Stochastic processes in the aetiopathogenesis of scleroderma

“…Others have reported associations between scleroderma and silica exposure 16 (relative risk (RR) ∼4–25 in males only) but not consistently, 7 solvent exposure 17 (RR 3 (confidence interval 1.9–4.6) in males, RR 1.8 (confidence interval 1.5–2.1) in females). Smoking does not appear to be a risk factor, 18 and the data on alcohol are inconsistent. Inconsistent findings have been reported on the associations with pet exposure, dental fillings, and prior blood transfusions and latitudinal gradients 7…”

Interstitial lung disease in South Africans with systemic sclerosis

“…In particular, silica exposure in gold-mining in men has been reported locally (22,23) , and internationally (24,25) to increase the risk of developing SSc by a factor of between 3 and 28. Although cigarette smoking has not been linked to the development of SSc, it has been linked to disease severity (26) .…”