Fetuin-A as a risk factor for mortality in hemodialysis patients.
OBJECTIVE
Fetuin A, a circulating inhibitor of calcification, is regulated as a negative acute-phase protein. However, its relationship with outcomes of patients undergoing hemodialysis has not been well evaluated. The aim of our study was to determine the association between fetuin-A and some factors of metabolism and their impact on all-cause mortality in hemodialysis patients.


METHODS
The study comprised 106 hemodialysis patients, 45 of whom were women. Levels of serum fetuin-A were measured by ELISA and serum intact parathyroid hormone (iPTH) by immunoassay in each patient. Serum Ca, serum P, Ca x P product, alkaline phosphatase, cholesterol, triglycerides, bicarbonate, albumin, homocysteine and C-reactive protein (CRP) were measured using routine laboratory methods. Survival rates were analyzed using Kaplan-Meier survival curves. A Cox regression model was used to access the possible influence of variables on all-cause mortality.


RESULTS
The mean value of fetuin-A was 15.3 +/- 3.8 g/l, range 5.5-23.7 g/l. Significant correlations were found between serum fetuin-A and serum iPTH (r = -0.239; P = 0.014), alkaline phosphatase (r = -0.240; P = 0.013), triglycerides (r = +0.236; P = 0.015) and serum albumin level (r = +0.286; P = 0.003). Patients were followed-up prospectively from the first day of the laboratory measurement for a maximum of 752 days or until death. A total of 24 patients died. Surviving patients had higher levels of fetuin-A (P = 0.005), serum cholesterol (P = 0.0001), triglycerides (P = 0.004), albumin (P = 0.0001) and homocysteine (P = 0.028). Kaplan-Meier survival analysis showed higher mortality in the first tertile of fetuin-A than in the third tertile (P = 0.0297). In our patients, serum Ca (P = 0.025), serum P (P = 0.040) and the Ca x P product (P = 0.039) were found to be predictors of mortality in the Cox multivariable regression model.


CONCLUSIONS
In patients undergoing hemodialysis, lower fetuin-A levels are associated with higher mortality. Metabolism of Ca and P were directly associated with higher mortality.
University Medical Center Maribor, Maribor, Slovenia.
Breda
B
Pecovnik Balon
Masa
M
Knehtl
Sebastjan
S
Bevc
Eva
E
Jakopin
Maksimiljan
M
Gorenjak
D000368:Aged; D000469:Alkaline Phosphatase / Q000097:blood; D001798:Blood Proteins / Q000378:metabolism*; D002118:Calcium / Q000097:blood; D002423:Cause of Death; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D007676:Kidney Failure, Chronic / Q000401:mortality* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D010758:Phosphorus / Q000097:blood; D011446:Prospective Studies; D012016:Reference Values; D006435:Renal Dialysis / Q000401:mortality*; D012307:Risk Factors; D012709:Serum Albumin / Q000378:metabolism; D017524:Slovenia; D013223:Statistics as Topic; D014280:Triglycerides / Q000097:blood; D060749:alpha-2-HS-Glycoprotein
C556354:AHSG protein, human; D001798:Blood Proteins; D010281:Parathyroid Hormone; D012709:Serum Albumin; D014280:Triglycerides; D060749:alpha-2-HS-Glycoprotein; D010758:Phosphorus; D000469:Alkaline Phosphatase; D002118:Calcium