title: Increased asthma and adipose tissue inflammatory gene expression with obesity and Inuit migration to a western country.
abstract: BACKGROUND
  An overlap between obesity and asthma exists, and inflammatory cells in adipose tissue could drive the development of asthma. Comparison of adipose tissue gene expression among Inuit living in Greenland to those in Denmark provides an opportunity to assess how changes in adipose tissue inflammation can be modified by migration and diet.
  
  
  OBJECTIVE
  To examine mast cell and inflammatory markers in adipose tissue and the association with asthma.
  
  
  METHODS
  Two Inuit populations were recruited, one living in Greenland and another in Denmark. All underwent adipose subcutaneous biopsy, followed by clinical assessment of asthma, and measurement of AHR. Adipose tissue biopsies were homogenised, RNA extracted, and PCR was performed to determine the relative gene expression of mast cell (tryptase, chymase, CPA3) and inflammatory markers (IL-6, IL-1β, and CD163).
  
  
  RESULTS
  Of the 1059 Greenlandic Inuit participants, 556 were living in Greenland and 6.4% had asthma. Asthma was increased in Denmark (9%) compared to Greenland (3.6%, p < 0.0001) and associated with increased adipose tissue IL-6 gene expression and increased BMI. There was no association between asthma and adipose tissue mast cell gene expression. Pro-inflammatory gene expression (IL-6, IL-1β) was higher in those living in Denmark, and with increasing BMI and dietary changes. The anti-inflammatory (M2) macrophage marker, CD163, was higher in Greenland-dwelling Inuit (p < 0.01).
  
  
  CONCLUSIONS
  No association was found between gene expression of mast cell markers in adipose tissue and asthma. Among Greenlandic Inuit, adipose tissue inflammation is also increased in those who migrate to Denmark, possibly as a result of dietary changes.
authors.affiliation: Department of Respiratory Medicine L, Bispebjerg Hospital, Copenhagen University Hospital, Copenhagen, Denmark. Electronic address: backer@dadlnet.dk.
authors.forename: Vibeke
authors.initials: V
authors.lastname: Backer
authors.affiliation: Priority Research Centre for Asthma and Respiratory Diseases, Hunter Medical Research Institute, The University of Newcastle, New Lambton Heights, NSW 2305 Australia; Department of Respiratory and Sleep Medicine, John Hunter Hospital, New Lambton, NSW 2305 Australia.
authors.forename: Katherine J
authors.initials: KJ
authors.lastname: Baines
authors.affiliation: Priority Research Centre for Asthma and Respiratory Diseases, Hunter Medical Research Institute, The University of Newcastle, New Lambton Heights, NSW 2305 Australia; Department of Respiratory and Sleep Medicine, John Hunter Hospital, New Lambton, NSW 2305 Australia.
authors.forename: Heather
authors.initials: H
authors.lastname: Powell
authors.affiliation: Department of Respiratory Medicine L, Bispebjerg Hospital, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Celeste
authors.initials: C
authors.lastname: Porsbjerg
authors.affiliation: Priority Research Centre for Asthma and Respiratory Diseases, Hunter Medical Research Institute, The University of Newcastle, New Lambton Heights, NSW 2305 Australia; Department of Respiratory and Sleep Medicine, John Hunter Hospital, New Lambton, NSW 2305 Australia.
authors.forename: Peter G
authors.initials: PG
authors.lastname: Gibson
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism / Q000473:pathology*; D000328:Adult; D001249:Asthma / Q000453:epidemiology / Q000208:ethnology* / Q000235:genetics*; D003718:Denmark / Q000453:epidemiology; D004032:Diet; D005260:Female; D015870:Gene Expression; D006116:Greenland / Q000453:epidemiology; D063426:Human Migration; D006801:Humans; D007249:Inflammation / Q000453:epidemiology / Q000208:ethnology / Q000235:genetics; D004930:Inuit; D008297:Male; D008407:Mast Cells / Q000378:metabolism / Q000473:pathology; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology / Q000208:ethnology* / Q000235:genetics*; D014171:Transients and Migrants / Q000706:statistics & numerical data*
keywords: Adipose tissue; Asthma; Inflammation; Mast cell markers