title: Determinants of serum tryptase in a general population: the relationship of serum tryptase to obesity and asthma.
abstract: BACKGROUND
  Recent studies indicate that mast cells are more abundant in the obese state. Total serum tryptase (ST) is a marker of mast cell numbers or activity. Since obesity and asthma have been consistently linked in epidemiological studies, a possible higher mast cell activity in obesity could be a factor between the two conditions. The aim of this study was to investigate determinants of ST and whether a potential association between obesity and allergic respiratory disease would be influenced by levels of ST in obese persons.
  
  
  METHODS
  Measurements of ST (ImmunoCAP Tryptase assay), atopy (skin prick test reactivity), methacholine bronchial hyperresponsiveness (BHR), body mass index (BMI) and serum lipids were performed in a general population of 1,216 persons aged 15-69 years.
  
  
  RESULTS
  ST increased significantly with increasing BMI. The median ST level increased from 3.3 μg/l in persons with BMI <25 to 4.4 μg/l in persons with BMI >30, p < 0.0001. Age (p < 0.0001), male sex (p = 0.0009) and smoking (p = 0.022) were positively associated with ST, whereas alcohol consumption (p = 0.005) was inversely associated with ST. ST was not associated with atopy, symptoms of allergic respiratory disease or BHR. A positive association between symptoms of allergic respiratory disease and obesity (OR = 1.98, 95% CI = 1.25-3.14) was not influenced by obesity-related differences in ST.
  
  
  CONCLUSIONS
  Increasing BMI was significantly associated with increasing ST and the prevalence of symptoms of allergic respiratory disease. However, mast cell activity/burden (assessed by ST levels) did not influence the association between BMI and asthma/rhinitis symptoms.
authors: Research Center for Prevention and Health, Glostrup University Hospital, Copenhagen, Denmark. Ruvafe01@glo.regionh.dk
authors: R V
authors: RV
authors: Fenger
authors: A
authors: A
authors: Linneberg
authors: C
authors: C
authors: Vidal
authors: L
authors: L
authors: Vizcaino
authors: L L
authors: LL
authors: Husemoen
authors: M
authors: M
authors: Aadahl
authors: A
authors: A
authors: Gonzalez-Quintela
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001249:Asthma / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D016535:Bronchial Hyperreactivity / Q000175:diagnosis / Q000453:epidemiology; D015981:Epidemiologic Factors; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology; D053802:Tryptases / Q000097:blood*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D053802:Tryptases