title: A prospective study on metabolic risk factors and gallbladder cancer in the metabolic syndrome and cancer (Me-Can) collaborative study.
abstract: OBJECTIVE
  To investigate the association between metabolic risk factors (individually and in combination) and risk of gallbladder cancer (GBC).
  
  
  METHODS
  The metabolic syndrome and cancer project (Me-Can) includes cohorts from Norway, Austria, and Sweden with data on 578,700 men and women. We used Cox proportional hazard regression models to calculate relative risks of GBC by body mass index (BMI), blood pressure, and plasma levels of glucose, cholesterol, and triglycerides as continuous standardised variables and their standardised sum of metabolic syndrome (MetS) z-score. The risk estimates were corrected for random error in measurements.
  
  
  RESULTS
  During an average follow-up of 12.0 years (SD = 7.8), 184 primary gallbladder cancers were diagnosed. Relative risk of gallbladder cancer per unit increment of z-score adjusted for age, smoking status and BMI (except for BMI itself) and stratified by birth year, sex and sub-cohorts, was for BMI 1.31 (95% confidence interval 1.11, 1.57) and blood glucose 1.76 (1.10, 2.85). Further analysis showed that the effect of BMI on GBC risk is larger among women in the premenopausal age group (1.84 (1.23, 2.78)) compared to those in the postmenopausal age group (1.29 (0.93, 1.79)). For the other metabolic factors no significant association was found (mid blood pressure 0.96 (0.71, 1.31), cholesterol 0.84 (0.66, 1.06) and serum triglycerides 1.16 (0.82, 1.64)). The relative risk per one unit increment of the MetS z-score was 1.37 (1.07, 1.73).
  
  
  CONCLUSIONS
  This study showed that increasing BMI and impaired glucose metabolism pose a possible risk for gallbladder cancer. Beyond the individual factors, the results also showed that the metabolic syndrome as an entity presents a risk constellation for the occurrence of gallbladder cancer.
authors.affiliation: Department of Medical Statistics, Informatics and Health Economics, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Wegene
authors.initials: W
authors.lastname: Borena
authors.affiliation: Department of Medical Statistics, Informatics and Health Economics, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Edlinger
authors.affiliation: Department of Public Health and Primary Health Care, University of Bergen, Bergen, Norway ; Norwegian Institute of Public Health, Oslo/Bergen, Norway.
authors.forename: Tone
authors.initials: T
authors.lastname: Bjørge
authors.affiliation: Department of Surgical and Perioperative Sciences, Urology and Andrology, Umeå University, Umeå, Sweden.
authors.forename: Christel
authors.initials: C
authors.lastname: Häggström
authors.affiliation: Department of Internal Medicine, Division of Gastroenterology and Hepatology, Sahlgrenska University Hospital, Gothenburg, Sweden.
authors.forename: Björn
authors.initials: B
authors.lastname: Lindkvist
authors.affiliation: Institute of Epidemiology and Medical Biometry, Ulm University, Ulm, Germany ; Agency for Preventive and Social Medicine, Bregenz, Austria.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Nagel
authors.affiliation: Department of Public Health and Primary Health Care, University of Bergen, Bergen, Norway ; Norwegian Institute of Public Health, Oslo/Bergen, Norway.
authors.forename: Anders
authors.initials: A
authors.lastname: Engeland
authors.affiliation: Department of Surgical and Perioperative Sciences, Urology and Andrology, Umeå University, Umeå, Sweden ; Institute of Preventive Medicine, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Tanja
authors.initials: T
authors.lastname: Stocks
authors.affiliation: Department of Medical Statistics, Informatics and Health Economics, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Susanne
authors.initials: S
authors.lastname: Strohmaier
authors.affiliation: Department of Surgery, Malmö University Hospital, Lund University, Malmö, Sweden.
authors.forename: Jonas
authors.initials: J
authors.lastname: Manjer
authors.affiliation: Department of Public Health and Primary Health Care, University of Bergen, Bergen, Norway.
authors.forename: Randi
authors.initials: R
authors.lastname: Selmer
authors.affiliation: Cancer Registry of Norway, Institute of Population-based Cancer Research, Montebello, Oslo, Norway.
authors.forename: Steinar
authors.initials: S
authors.lastname: Tretli
authors.affiliation: Agency for Preventive and Social Medicine, Bregenz, Austria.
authors.forename: Hans
authors.initials: H
authors.lastname: Concin
authors.affiliation: Department of Public Health and Clinical Medicine, Nutritional Research, Umeå University, Umeå, Sweden.
authors.forename: Goran
authors.initials: G
authors.lastname: Hallmans
authors.affiliation: Department of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden.
authors.forename: Håkan
authors.initials: H
authors.lastname: Jonsson
authors.affiliation: Department of Surgical and Perioperative Sciences, Urology and Andrology, Umeå University, Umeå, Sweden.
authors.forename: Pär
authors.initials: P
authors.lastname: Stattin
authors.affiliation: Department of Medical Statistics, Informatics and Health Economics, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Hanno
authors.initials: H
authors.lastname: Ulmer
mesh_terms: D000328:Adult; D000368:Aged; D001317:Austria; D001786:Blood Glucose / Q000378:metabolism; D002784:Cholesterol / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D005706:Gallbladder Neoplasms / Q000097:blood / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood / Q000150:complications / Q000453:epidemiology*; D008875:Middle Aged; D009664:Norway; D011446:Prospective Studies; D012307:Risk Factors; D013548:Sweden; D014280:Triglycerides / Q000097:blood
chemical_list: D001786:Blood Glucose; D014280:Triglycerides; D002784:Cholesterol