title: Relationship between calcium channel blockers and skin fibrosis in patients with systemic sclerosis.
abstract: OBJECTIVE
  Recent experimental evidence suggests that calcium channel blockers (CCBs) may have anti-fibrotic effects on liver and pulmonary fibrosis. We aimed to investigate whether use of CCBs was associated with the skin fibrosis in patients with systemic sclerosis (SSc).
  
  
  METHODS
  Based on the 5-year follow-up data from the Canadian Scleroderma Research Group registry, we used the generalised estimating equations (GEE) model to assess the relationship between use of CCBs and the primary outcome of skin fibrosis measured by the modified Rodnan skin score (mRSS). We also used GEE models to explore the associations between use of CCBs and risk of secondary outcomes including digital ulcers, pulmonary fibrosis, calcinosis, and scleroderma renal crisis.
  
  
  RESULTS
  There were 1547 patients (1330 females) with SSc included in this study. Their mean age was 55.5 years and there were 606 patients taking CCBs at baseline. No significant difference in mRSS between the use versus non-use of CCBs was found in the multivariable analysis: mean difference = -0.19 (95% confidence interval: -0.62, 0.23), p-value = 0.37. Use of CCBs was not significantly related to risk of secondary outcomes, with an odds ratio (OR) of 1.13 for digital ulcers, 0.94 for pulmonary fibrosis, 0.90 for calcinosis and 1.69 for scleroderma renal crisis, respectively.
  
  
  CONCLUSIONS
  No significant associations between use of CCBs and skin fibrosis, digital ulcers, pulmonary fibrosis, calcinosis and scleroderma renal crisis were found in patients with SSc. More evidence from other well-designed studies would be required to confirm these findings.
authors.affiliation: Department of Clinical Epidemiology & Biostatistics, McMaster University, Hamilton; and St. Joseph's Healthcare Hamilton, ON, Canada. lig28@mcmaster.ca.
authors.forename: Guowei
authors.initials: G
authors.lastname: Li
authors.affiliation: St. Joseph's Healthcare Hamilton, ON; and Division of Rheumatology, Department of Medicine, McMaster University, Hamilton, ON, Canada.
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Adachi
authors.affiliation: Department of Clinical Epidemiology & Biostatistics, McMaster University, Hamilton; and St. Joseph's Healthcare Hamilton, ON, Canada.
authors.forename: Ji
authors.initials: J
authors.lastname: Cheng
authors.affiliation: Department of Clinical Epidemiology & Biostatistics, McMaster University, Hamilton; and St. Joseph's Healthcare Hamilton, ON, Canada.
authors.forename: Lehana
authors.initials: L
authors.lastname: Thabane
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, SMBD Jewish General Hospital, Montreal, QC; and Division of Rheumatology, Faculty of Medicine, McGill University, Montreal, QC, Canada.
authors.forename: Marie
authors.initials: M
authors.lastname: Hudson
authors.affiliation: Mitogen Advanced Diagnostics Laboratory, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
authors.forename: Marvin J
authors.initials: MJ
authors.lastname: Fritzler
authors.affiliation: Department of Clinical Epidemiology & Biostatistics, McMaster University, Hamilton, ON, Canada.
authors.forename: Steven
authors.initials: S
authors.lastname: Lorenzi
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, SMBD Jewish General Hospital, Montreal, QC; and Division of Rheumatology, Faculty of Medicine, McGill University, Montreal, QC, Canada.
authors.forename: Murray
authors.initials: M
authors.lastname: Baron
authors.affiliation: St. Joseph's Healthcare Hamilton, ON; and Division of Rheumatology, Department of Medicine, McMaster University, Hamilton, ON, Canada. mlarche@mcmaster.ca.
authors.forename: Maggie
authors.initials: M
authors.lastname: Larché
mesh_terms: D000328:Adult; D000368:Aged; D002121:Calcium Channel Blockers / Q000009:adverse effects*; D005260:Female; D005355:Fibrosis; D006801:Humans; D008297:Male; D008875:Middle Aged; D012595:Scleroderma, Systemic / Q000188:drug therapy*; D012867:Skin / Q000473:pathology*
chemical_list: D002121:Calcium Channel Blockers