title: Prevalence and risk factors of gallbladder polypoid lesions in Chinese petrochemical employees.
abstract: OBJECTIVE
  To investigate the prevalence and risk factors of polypoid lesions of the gallbladder (PLGs) in petrochemical employees in Ningbo, Zhejiang Province, China.
  
  
  METHODS
  All active and retired employees aged 20-90 years (n = 11098) of a refinery and chemical plant in eastern China were requested to participate in a health survey. The participants were subjected to interview, physical examination, laboratory assessments and ultrasonography. All the participants were invited to have a physical examination after a face-to-face interview. Fasting blood samples were obtained from the antecubital vein, and the samples were used for the analysis of biochemical values. Abdominal ultrasonography was conducted.
  
  
  RESULTS
  A total of 10461 (7331 men and 3130 women) current and former petrochemical employees attended for screening. The overall prevalence of post-cholecystectomy, gallstones and PLGs was 0.9%, 5.2% and 7.4%, respectively. Compared with the increased prevalence of either gallstones or post-cholecystectomy in older persons, PLGs were more common in the middle-aged, peaking in those aged 40-59 years. Excluding the patients with gallstones, gallstones mixed with PLGs, or those who had undergone cholecystectomy, in the remaining 9828 participants, the prevalence of PLGs in men (8.9%) was significantly higher than that in women (5.5%, P < 0.001). The analyzed risk factors with increased OR for the development of PLGs were male gender (OR = 1.799, P < 0.001), age ≥ 30 years (OR = 2.699, P < 0.001) and hepatitis B surface antigen (HBsAg) positivity (OR = 1.374, P = 0.006).
  
  
  CONCLUSIONS
  PLGs are not rare among Chinese petrochemical employees. Male gender, HBsAg positivity, and middle age are risk factors for developing PLGs.
authors.affiliation: Department of Endocrinology and Metabolism, Affiliated Hospital of Medical College of Ningbo University, Ningbo 315020, Zhejiang Province, China.
authors.forename: Yu-Shan
authors.initials: YS
authors.lastname: Mao
authors.forename: Yi-Feng
authors.initials: YF
authors.lastname: Mai
authors.forename: Fu-Jun
authors.initials: FJ
authors.lastname: Li
authors.forename: Yan-Ming
authors.initials: YM
authors.lastname: Zhang
authors.forename: Ke-Min
authors.initials: KM
authors.lastname: Hu
authors.forename: Zhong-Li
authors.initials: ZL
authors.lastname: Hong
authors.forename: Zhong-Wei
authors.initials: ZW
authors.lastname: Zhu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure; D002681:China / Q000453:epidemiology; D019652:Extraction and Processing Industry; D005260:Female; D005704:Gallbladder / Q000000981:diagnostic imaging / Q000473:pathology*; D005705:Gallbladder Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology*; D042882:Gallstones / Q000453:epidemiology*; D006306:Health Surveys; D006514:Hepatitis B Surface Antigens; D006801:Humans; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure; D016272:Occupational Health; D016017:Odds Ratio; D010578:Petroleum; D011127:Polyps / Q000000981:diagnostic imaging / Q000453:epidemiology*; D015995:Prevalence; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014463:Ultrasonography; D055815:Young Adult
chemical_list: D006514:Hepatitis B Surface Antigens; D010578:Petroleum
keywords: Chinese; Gallbladder; Polypoid lesions; Prevalence; Risk factors