title: Incidence of granulomatosis with polyangiitis (Wegener's) in Greenland and the Faroe Islands: epidemiology of an ANCA-associated vasculitic syndrome in two ethnically distinct populations in the North Atlantic area.
abstract: OBJECTIVE
  Previous studies suggest that the incidence of granulomatosis with polyangiitis (Wegener's; GPA) increases along a south-north gradient in the Northern Hemisphere with an incidence of 8.0/million/year reported for the population of Northern Norway. In the present study, we assessed the incidence of GPA in the predominantly Inuit population of Greenland and in the Caucasian population of the Faroe Islands.
  
  
  METHODS
  Greenlandic and Faroese patients affected by severe rheumatic diseases are routinely referred to the National University Hospital in Denmark for treatment. By means of the Danish National Hospital register, we identified all Greenlandic and Faroese patients treated at the hospital under a diagnosis of GPA during 1992-2011. For each patient, the GPA diagnosis was validated by medical files review.
  
  
  RESULTS
  One patient born and living in Greenland and 6 from the Faroe Islands were identified. The incidence of GPA was 1.0/million/year (95% CI 0.02-5.6) in Greenland and 6.4/million/year (95% 2.4-14.0) in the Faroe Islands. During the period of study, no cases of GPA occurred among Greenlanders aged 0-44 years, while an incidence of 4.1/million/year (95% CI: 0.1-22.9) was calculated for those aged ≥45 years. In the Faroese population, incidences of 1.7/million/year (95% CI 0.4-9.4) and 14.8/million/year (95% CI 4.8-34.6) were calculated for the age-groups 0-44 and ≥45 years, respectively.
  
  
  CONCLUSIONS
  The occurrence of GPA is lower among Inuit in Greenland than among Caucasians living in the Faroe Islands. This observation demonstrates that the risk of GPA varies across ethnic groups populating the northernmost regions of the world.
authors.affiliation: Department of Infectious Diseases and Rheumatology, The National University Hospital, Rigshospitalet, Copenhagen, Denmark. mikkelf@dadlnet.dk
authors.forename: M
authors.initials: M
authors.lastname: Faurschou
authors.forename: M
authors.initials: M
authors.lastname: Helleberg
authors.forename: N
authors.initials: N
authors.lastname: Obel
authors.forename: B
authors.initials: B
authors.lastname: Baslund
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood; D015415:Biomarkers / Q000097:blood; D002648:Child; D002675:Child, Preschool; D003718:Denmark / Q000453:epidemiology; D005260:Female; D014890:Granulomatosis with Polyangiitis / Q000097:blood / Q000175:diagnosis / Q000208:ethnology* / Q000276:immunology; D006116:Greenland / Q000453:epidemiology; D006785:Hospitals, University; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D004930:Inuit / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D053146:Myeloblastin / Q000276:immunology; D012042:Registries; D012307:Risk Factors; D013997:Time Factors; D044465:White People / Q000706:statistics & numerical data*; D055815:Young Adult
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic; D015415:Biomarkers; D053146:Myeloblastin