BACKGROUND AND AIMS: Studies have suggested that smokers may have a higher risk of primary biliary cholangitis (PBC) although the results have been inconsistent. This systematic review and meta-analysis aim to better characterize the risk of PBC among smokers by identifying all relevant studies and summarizing their results together. METHODS: A comprehensive literature review was conducted using Embase and Pubmed/MEDLINE databases from inception to September 2018 to identify all studies which compared the risk of PBC among current, ever and former smokers to non-smokers. Effect estimates from each study were extracted and combined together using the random-effect, generic inverse variance method of DerSimonian and Laird. RESULTS: Nine case-control studies with 21,577 participants met the eligibility criteria and were included in the meta-analysis. The risk of PBC among ever smokers was significantly higher than non-smokers with the pooled odds ratio (OR) of 1.31 (95% CI, 1.03-1.67; I 2 89%). Subgroup analysis found that the risk was higher in both former smokers (pooled OR 1.36; 95% CI, 1.01-1.84; I 2 75%) and current smokers (pooled OR 1.18; 95% CI, 0.94-1.50; I 2 79%), although the latter did not reach statistical significance. Immunomodulatory and cytotoxic effect of cigarettes were the possible mechanisms behind this increased risk. CONCLUSIONS: A significantly increased risk of PBC among individuals who ever smoked was observed in this study, adding to the already long list of harmful health consequences of smoking.
|Original language||English (US)|
|Number of pages||7|
|Journal||Journal of gastrointestinal and liver diseases : JGLD|
|State||Published - Jun 1 2019|
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