Non-alcoholic fatty liver disease and periodontal disease: A systematic review and meta-analysis of cross-sectional studies

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease, comprising hepatic steatosis, and nonalcoholic steatohepatitis. Periodontal disease (PD) may be a risk factor for the evolution of liver cirrhosis. This study aimed to evaluate the association between NAFLD and PD. We searched in Pubmed, Scopus, Cochrane, and Lilacs databases with descriptors (Non-alcoholic Fatty Liver Disease OR (non-alcoholic AND Fatty Liver AND disease) OR Nonalcoholic Steatohepatitis) AND (Periodontal Disease OR Gingivitis OR Periodontitis) from January 2021 to September 2021. We selected, by the abstract, cross-sectional, cohort (prospective and retrospective), and case-control studies that address periodontal disease in patients with Non-alcoholic Fatty Liver Disease, and aged >= 18 years. The search was without the restriction of language and publication time. The search resulted in 954 articles. After applying the selection criteria, five cross-sectional studies remained. A metanalysis combined the study estimates of periodontal disease in NAFLD, by using the random effects. The Odds Ratio (1.91; 95% CI 1.21-3.02; P = 0.006) indicates that the chance of presenting Periodontal disease is 91% higher in individuals with NAFLD when compared with individuals without NAFLD. There are few studies with appropriate methodology to produce sound evidence about the causal relationship between the use of NAFLD and PD, however, studies support the association. So, dental staff must be aware of this association for better management of periodontal disease in patients with NAFLD.