Patients with Autoimmune Hepatitis Report Lower Lifetime Coffee Consumption

BACKGROUND: Coffee drinking has been associated with decreased risk of some autoimmune diseases as well liver disease and outcomes. Environmental factors, such as coffee consumption, are yet to be assessed among patients with autoimmune hepatitis (AIH). AIM: We sought to investigate the relationship between coffee consumption and risk of AIH utilizing the Genetic Repository of Autoimmune Liver Disease and Contributing Exposures (GRACE) database. METHODS: Lifetime coffee drinking was collected from 358 AIH patients (cases) and 564 volunteers (controls) from primary care visits. Groups were compared utilizing the Wilcoxon rank sum test for continuous variables and the Chi-square test for discrete variables. Logistic regression was used to analyze the effects of different coffee parameters (time, frequency, and cups) after adjusting for age, sex, education, smoking status, BMI, and daily activity. RESULTS: 24.6% of AIH patients never drank coffee compared to 15.7% of controls (p < 0.001), and only 65.6% were current drinkers compared with 77% of controls (p < 0.001). Among “ever” coffee drinkers, AIH patients consumed fewer lifetime cups of coffee per month (45 vs. 47 for controls, p < 0.001) and spent less percentage of life drinking coffee (62.5% vs. 69.1% for controls, p < 0.001). Concurrent inflammatory bowel disease was higher among AIH patients than controls (5.7% vs. 1.2%, p < 0.001), yet did not significantly contribute to “never” coffee drinking status. The relationship between lower coffee consumption and AIH persisted even after controlling for covariates. CONCLUSIONS: Coffee consumption is lower among patients with AIH compared to controls.