title: Altered matrix metalloproteinase 9 and tissue inhibitor of metalloproteinases 1 levels in children with primary hypertension.
abstract: Matrix metalloproteinases (MMP) and tissue inhibitors of metalloproteinases (TIMP) are involved in cardiovascular remodeling in hypertension. Because metabolic abnormalities typical of metabolic syndrome is the dominant phenotype of primary hypertension in children, we hypothesized that MMP-9 and TIMP-1 plasma concentrations are altered in hypertensive children and correlate with metabolic abnormalities and target organ damage.
  
  
  
  A total of 109 children (15.6, 10-17 years) with untreated primary hypertension were included to the study. The control group consisted of 74 healthy, normotensive children.
  
  
  
  Plasma MMP-9, TIMP-1 concentrations, and MMP-9/TIMP-1 ratio were significantly elevated in hypertensive boys in comparison with normotensive boys (P = 0.0001, P = 0.04, and P = 0.001, respectively), whereas there were no differences between hypertensive and normotensive girls. The levels of MMP-9 and TIMP-1 as well as MMP-9/TIMP-1 ratio were not associated either with hypertension stage, left ventricular hypertrophy, or carotid intima-media thickness. However, in a subgroup of 30 hypertensive patients in whom arterial stiffness was measured, TIMP-1 concentrations correlated with aortic pulse pressure (P < 0.05; r = 0.367), augmentation pressure (P < 0.05; r = 0.428), and augmentation index (P < 0.05; r = 0.404).Only hypertensive boys presented negative correlations of both MMP-9 and TIMP-1 levels with high-density lipoprotein cholesterol (r = -0.254, P = 0.01 and r = -0.241, P = 0.02, respectively).
  
  
  
  Hypertensive boys but not girls had elevated MMP-9 and TIMP-1 plasma concentrations, which indicates sex-related role of MMP/TIMP system in pediatric hypertension. The correlation between serum TIMP-1 and markers of arterial stiffness indicates on the involvement of TIMPs in arterial remodeling.
authors.affiliation: aDepartment of Nephrology, Kidney Transplantation and Arterial Hypertension, The Children's Memorial Health Institute bDepartment of Immunology, Children's Memorial Health Institute, Warsaw cDepartment of Immunology, Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz dDepartment of Biochemistry and Experimental Medicine, The Children's Memorial Health Institute eDepartment of Public Health, Children's Memorial Health Institute, Warsaw, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Niemirska
authors.forename: Mieczysław
authors.initials: M
authors.lastname: Litwin
authors.forename: Joanna
authors.initials: J
authors.lastname: Trojanek
authors.forename: Lidia
authors.initials: L
authors.lastname: Gackowska
authors.forename: Izabela
authors.initials: I
authors.lastname: Kubiszewska
authors.forename: Aldona
authors.initials: A
authors.lastname: Wierzbicka
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Kułaga
authors.forename: Jacek
authors.initials: J
authors.lastname: Michałkiewicz
mesh_terms: D000293:Adolescent; D062186:Arterial Pressure; D059168:Carotid Intima-Media Thickness; D016022:Case-Control Studies; D002648:Child; D000075222:Essential Hypertension; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000201:enzymology*; D017379:Hypertrophy, Left Ventricular / Q000097:blood; D008075:Lipoproteins, HDL / Q000097:blood; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000097:blood*; D012737:Sex Factors; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000097:blood*
chemical_list: D008075:Lipoproteins, HDL; C560822:TIMP1 protein, human; D019715:Tissue Inhibitor of Metalloproteinase-1; D020780:Matrix Metalloproteinase 9