Risk factors of primary biliary cirrhosis in mid-west China

Background/Aims: PBC is an autoimmune liver disease with unclear etiology, although environmental and genetic interactions have been proposed in previous studies. We conducted a large case-control study in Mid-West China to indentify PBC risk factors and compare study findings with previous studies. Methods and material: Data of 512 PBC patients and 761 age-, sex-, residential location-matched controls were recorded by questionnaire. Questionnaire data on general, psychological, lifestyle conditions and medical history from all subjects and data on menstrual and reproductive features from females were collected and examined. Data from cases and controls were compared using logistic regressions, adjusting for age, sex and BMI. Results: Psychological stress, hair dye usage, allergy, urinary tract infection, surgery and the number of live births, abnormal pregnancy and pruritus during pregnancy were significantly associated with increased risk of PBC. However, outdoors exposure time (OR: 0.928; 95% CI: 0.879, 0.980) may be a protective factor in the development of PBC. Conclusions: This study confirms risk factors previously reported and first indentifies the association with psychological stress, outdoor exposure time and PBC. Further investigation is needed to examine these findings.