title: Provitamin A carotenoids are independently associated with matrix metalloproteinase-9 in plasma samples from a general population.
abstract: OBJECTIVE
  Carotenoids in plasma are inversely associated with cardiovascular risk. Low levels can be explained by low dietary intake but also by a number of other factors including inflammatory activity. Given that matrix metalloproteinase (MMP)-9 has an important role in inflammation and cardiovascular disease, we hypothesized that circulating MMP-9 levels would be inversely related to total or single carotenoids in a general population cohort.
  
  
  METHODS
  A well-characterized population-based cohort of 285 Swedish men and women (45-69 years) was used for the present study. The intake of carotenoid-rich fruits and vegetables was estimated from a food frequency questionnaire. Levels of MMP-9, C-reactive protein (CRP), interleukin (IL)-6 and six major carotenoids [β-cryptoxanthine, α-carotene, β-carotene, lutein (+zeaxanthin) and lycopene] were determined in plasma.
  
  
  RESULTS
  Lower plasma levels of total and single carotenoids were associated with lower dietary intake of carotenoids, older age, male sex, lower physical activity, higher alcohol consumption, higher body mass index (BMI), higher systolic and diastolic blood pressures, lower levels of total cholesterol and HDL cholesterol and higher levels of CRP, IL-6 and MMP-9. After multivariate adjustments, plasma levels of total carotenoids and provitamin A carotenoids (β-cryptoxanthine, α-carotene and β-carotene) remained independently associated with sex, dietary intake of carotenoids, BMI, HDL cholesterol and MMP-9, whilst associations with CRP and IL-6 were not maintained. Neither dietary intake of carotenoid-rich fruits and vegetables, nor vitamin supplement use was associated with MMP-9, CRP or IL-6 levels.
  
  
  CONCLUSIONS
  Plasma carotenoids were associated with a variety of factors including age, sex, dietary intake and metabolic variables. A new finding was the independent relationship in plasma between low provitamin A carotenoids and high MMP-9, suggesting a link between these carotenoids, matrix turnover and arterial remodelling.
authors.affiliation: Division of Cardiovascular Medicine, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Rydén
authors.forename: P
authors.initials: P
authors.lastname: Garvin
authors.forename: M
authors.initials: M
authors.lastname: Kristenson
authors.forename: P
authors.initials: P
authors.lastname: Leanderson
authors.forename: J
authors.initials: J
authors.lastname: Ernerudh
authors.forename: L
authors.initials: L
authors.lastname: Jonasson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002338:Carotenoids / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000097:blood*; D008875:Middle Aged; D014801:Vitamin A
chemical_list: D014801:Vitamin A; D002338:Carotenoids; D020780:Matrix Metalloproteinase 9