title: Tobacco Smoking Is Not Associated With Accelerated Liver Disease in Human Immunodeficiency Virus-Hepatitis C Coinfection: A Longitudinal Cohort Analysis.
abstract: Background.  Tobacco smoking has been shown to be an independent risk factor for liver fibrosis in hepatitis C virus (HCV) infection in some cross-sectional studies. No longitudinal study has confirmed this relationship, and the effect of tobacco exposure on liver fibrosis in human immunodeficiency virus (HIV)-HCV coinfected individuals is unknown. Methods.  The study population consisted of participants from the Canadian Co-infection Cohort study (CTN 222), a multicenter longitudinal study of HIV-HCV coinfected individuals from 2003 to 2014. Data were analyzed for all participants who did not have significant fibrosis or end-stage liver disease (ESLD) at baseline. The association between time-updated tobacco exposure (ever vs nonsmokers and pack-years) and progression to significant liver fibrosis (defined as an aspartate-to-platelet ratio index [APRI] ≥1.5) or ESLD was assessed by pooled logistic regression. Results.  Of 1072 participants included in the study, 978 (91%) had ever smoked, 817 (76%) were current smokers, and 161 (15%) were previous smokers. Tobacco exposure was not associated with accelerated progression to significant liver fibrosis nor with ESLD when comparing ever vs never smokers (odds ratio [OR] = 1.06, 95% confidence interval [CI], 0.43-1.69 and OR = 1.20, 95% CI, 0.21-2.18, respectively) or increases in pack-years smoked (OR = 1.05, 95% CI, 0.97-1.14 and OR = 0.94, 95% CI, 0.83-1.05, respectively). Both time-updated alcohol use in the previous 6 months and presence of detectable HCV ribonucleic acid were associated with APRI score ≥1.5. Conclusions.  Tobacco exposure does not appear to be associated with accelerated progression of liver disease in this prospective study of HIV-HCV coinfected individuals.
authors.affiliation: Chronic Viral Illnesses Service , Division of Infectious Diseases and Research Institute of the McGill University Health Centre , Montreal.
authors.forename: Cecilia T
authors.initials: CT
authors.lastname: Costiniuk
authors.affiliation: Department of Epidemiology , Biostatistics and Occupational Health, McGill University , Montreal, Quebec.
authors.forename: Laurence
authors.initials: L
authors.lastname: Brunet
authors.affiliation: Chronic Viral Illnesses Service , Division of Infectious Diseases and Research Institute of the McGill University Health Centre , Montreal.
authors.forename: Kathleen C
authors.initials: KC
authors.lastname: Rollet-Kurhajec
authors.affiliation: Division of Infectious Diseases, The Ottawa Hospital, Ontario, Canada; Canadian HIV Trials Network, Vancouver, British Columbia.
authors.forename: Curtis L
authors.initials: CL
authors.lastname: Cooper
authors.affiliation: Canadian HIV Trials Network, Vancouver, British Columbia; Division of Infectious Diseases, University Health Network, University of Toronto, Ontario.
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Walmsley
authors.affiliation: Canadian HIV Trials Network, Vancouver, British Columbia; Southern Alberta HIV Clinic, Calgary.
authors.forename: M John
authors.initials: MJ
authors.lastname: Gill
authors.affiliation: Centre de Recherche du Centre Hospitalier de l'Université de Montréal , Quebec , Canada.
authors.forename: Valérie
authors.initials: V
authors.lastname: Martel-Laferriere
authors.affiliation: Chronic Viral Illnesses Service, Division of Infectious Diseases and Research Institute of the McGill University Health Centre, Montreal; Canadian HIV Trials Network, Vancouver, British Columbia.
authors.forename: Marina B
authors.initials: MB
authors.lastname: Klein
keywords: HCV; HIV; cohort study; liver disease; tobacco