Serum Osteoprotegerin Levels and the Extent of Aortic Calcification in Hemodialysis Patients

Lhee, Hyun Young; Kim, Hyang; Lee, Kyu Beck; Lee, Youngrae

Abstract

BACKGOUND: Vascular calcification is highly correlated with cardiovascular disease mortality, especially in patients with end-stage renal disease (ESRD). Recent experimental research has implicated osteoprotegerin (OPG) in medial arterial calcification. The present study aims to examine whether serum OPG level is associated with the extent of aortic calcification in hemodialysis patients.
METHODS
We studied 57 ESRD patients (59.5+/-14.1 years) on maintenance hemodialysis. Serum OPG level was measured by enzyme-linked immunosorbent assay. Abdominal aortic calcific deposits index (AAC index) was analysed with lateral lumbar radiograms. Patients were classified into tertile groups according to their AAC index: group I (0, n= 18), group II (1-4, n=18) and group III (5-18, n=21). Brachial ankle pulse wave velocity (baPWV) was also measured.
RESULTS
Serum OPG level was greater in patients with higher AAC index than in those with lower AAC index but it was not statistically significant (group I: 409.8+/-343.5 pg/mL, group II: 575.9+/-723.3 pg/mL and group III: 660.8+/-593.5 pg/mL, p=0.399). There was a trend that serum OPG level was positively associated with AAC index, but it was not statistically significant (r=0.089, p=0.511). Serum OPG level showed positive correlation with age and pulse pressure. AAC index positively related with age and baPWV.
CONCLUSION
Serum OPG levels seems to be positively related to AAC index by lateral lumbar radiograms, but it was not statistically significant. We suggest more extended studies to determine that serum OPG is helpful clinical marker for the extent of vascular calcification in maintenance hemodialysis patients.