Metabolism of collagen is altered in hypertensives with increased intima media thickness.
BACKGROUND
Increased intima media thickness (IMT) of common carotid arteries (CCAs) and left ventricular mass index (LVMI) are independent risk factors for vascular events and may be related to accumulation of extracellular proteins due to altered metabolism of collagen.


METHODS
IMT and LVMI were measured ultrasonographically in 50 males with newly diagnosed, untreated, essential hypertension (HTN, 37.7 +/- 13.1 years), and 14 controls (C, 32.6 +/- 9.7 years). Serum levels of procollagen type I carboxy-terminal propeptide (PICP), procollagen type III amino-terminal propeptide (PIIINP), carboxy-terminal telopeptide (ICTP), matrix metalloproteinase (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) were determined using immunoassays.


RESULTS
IMT was significantly higher in HTN than in C (0.6 +/- 0.1 vs 0.4 +/- 0.1 mm, p < 0.001) as well as LVMI (119.5 +/- 39.9 vs 106.8+/-18.7 g/m2, p = 0.04) and serum TIMP-1 (in HNT 691.7 +/- 124.6 ng/ml; in C 577.5+/-70.8 ng/ml, p < 0.001). Other parameters did not differ between these groups. The sum of PICP and ICTP was higher in HTN (165.0 +/- 46.9 microg/l), than in C (147.1 +/- 26.0 microg/l, p = 0.03). TIMP-1 correlated with IMT (r = 0.33, p = 0.02) in hypertensives.


CONCLUSIONS
We suggest that the collagenase-anticollagenase system is abnormal in essential hypertension and contributes to cardiovascular remodeling. Increased IMT may be related to the accumulation of extracellular proteins due to altered metabolism of collagen.
Szmigielski
Cezary
C
Department of Internal Medicine, Hypertension and Vascular Diseases, The Medical University of Warsaw, Warsaw, Poland, Banacha Street 1A, 02-097 Warsaw, Poland. cezary@amwaw.edu.pl
Raczkowska
Malgorzata
M
Styczynski
Grzegorz
G
Pruszczyk
Piotr
P
Gaciong
Zbigniew
Z
D000328:Adult; D016022:Case-Control Studies; D003094:Collagen / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D006801:Humans; D006973:Hypertension / Q000378:metabolism* / Q000473:pathology; D017379:Hypertrophy, Left Ventricular / Q000209:etiology; D008297:Male; D008875:Middle Aged; D011347:Procollagen / Q000097:blood; D017539:Tunica Intima / Q000000981:diagnostic imaging / Q000473:pathology*; D017540:Tunica Media / Q000000981:diagnostic imaging / Q000473:pathology; D014463:Ultrasonography
D016326:Extracellular Matrix Proteins; D011347:Procollagen; D003094:Collagen