title: Circulating matrix metalloproteinase-9 is associated with cardiovascular risk factors in a middle-aged normal population.
abstract: BACKGROUND
  Elevated levels of circulating matrix metalloproteinase-9 (MMP-9) have been demonstrated in patients with established coronary artery disease (CAD). The aim of this study was to analyse levels of MMP-9 in a population free from symptomatic CAD and investigate their associations with cardiovascular (CV) risk factors, including C-reactive protein (CRP).
  
  
  METHODS
  A cross-sectional study was performed in a population based random sample aged 45-69 (n = 345, 50% women). MMP-9 levels were measured in EDTA-plasma using an ELISA-method. CV risk factors were measured using questionnaires and standard laboratory methods.
  
  
  RESULTS
  Plasma MMP-9 was detectable in all participants, mean 38.9 ng/mL (SD 22.1 ng/mL). Among individuals without reported symptomatic CAD a positive association (p<0.001) was seen, for both men and women, of MMP-9 levels regarding total risk load of eight CV risk factors i.e. blood pressure, dyslipidemia, diabetes, obesity, smoking, alcohol intake, physical activity and fruit and vegetable intake. The association was significant also after adjustment for CRP, and was not driven by a single risk factor alone. In regression models adjusted for age, sex, smoking, alcohol intake and CRP, elevated MMP-9 levels were independently positively associated with systolic blood pressure (p = 0.037), smoking (p<0.001), alcohol intake (p = 0.003) and CRP (p<0.001). The correlation coefficient between MMP-9 and CRP was r = 0.24 (p<0.001).
  
  
  CONCLUSIONS
  In a population without reported symptomatic CAD, MMP-9 levels were associated with total CV risk load as well as with single risk factors. This was found also after adjustment for CRP.
authors.affiliation: Division of Community Medicine, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden. peter.garvin@ihs.liu.se
authors.forename: Peter
authors.initials: P
authors.lastname: Garvin
authors.forename: Lennart
authors.initials: L
authors.lastname: Nilsson
authors.forename: John
authors.initials: J
authors.lastname: Carstensen
authors.forename: Lena
authors.initials: L
authors.lastname: Jonasson
authors.forename: Margareta
authors.initials: M
authors.lastname: Kristenson
mesh_terms: D002318:Cardiovascular Diseases / Q000097:blood / Q000201:enzymology*; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000097:blood*; D008875:Middle Aged; D012016:Reference Values; D012307:Risk Factors
chemical_list: D020780:Matrix Metalloproteinase 9