Useful biochemical markers for diagnosing renal osteodystrophy in predialysis end-stage renal failure patients.
BACKGROUND
Various biochemical markers have been evaluated in dialysis patients for the diagnosis of renal osteodystrophy (ROD). However, their value in predialysis patients with end-stage renal failure (ESRF) is not yet clear.


METHODS
Bone histomorphometric evaluation was performed and biochemical markers of bone turnover were determined in serum of an unselected predialysis ESRF population (N = 84).


RESULTS
Significant (P < 0.005) differences between the five groups with ROD (ie, normal bone [N = 32], adynamic bone [ABD; N = 19], hyperparathyroidism [N = 8], osteomalacia [OM; N = 10], and mixed lesion [N = 15]) were noted for intact parathyroid hormone, total (TAP) and bone alkaline phosphatase (BAP), osteocalcin (OC), and serum calcium levels. Serum creatinine and (deoxy)pyridinoline levels did not differ between groups. For the diagnosis of ABD, an OC level of 41 microg/L or less (< or =7.0 nmol/L) had a sensitivity of 83% and specificity of 67%. The positive predictive value (PPV) for the population under study was 47%. The combination of an OC level of 41 ng/L or less (< or =7.0 nmol/L) with a BAP level of 23 U/L or less increased the sensitivity, specificity, and PPV to 72%, 89%, and 77%, respectively. ABD and normal bone taken as one group could be detected best by a BAP level of 25 U/L or less and TAP level of 84 U/L or less, showing sensitivities of 72% and 88% and specificities of 76% and 60%, corresponding with PPVs of 89% and 85%, respectively. In the absence of aluminum or strontium exposure, serum calcium level was found to be a useful index for the diagnosis of OM.


CONCLUSIONS
OC, TAP, BAP, and serum calcium levels are useful in the diagnosis of ABD, normal bone, and OM in predialysis patients with ESRF.
Department of Nephrology-Hypertension, University of Antwerp, Belgium.
An R J
AR
Bervoets
Goce B
GB
Spasovski
Geert J
GJ
Behets
Geert
G
Dams
Momir H
MH
Polenakovic
Katica
K
Zafirovska
Viviane O
VO
Van Hoof
Marc E
ME
De Broe
Patrick C
PC
D'Haese
D000328:Adult; D000368:Aged; D000469:Alkaline Phosphatase / Q000097:blood*; D015415:Biomarkers; D001842:Bone and Bones / Q000033:anatomy & histology / Q000473:pathology*; D002118:Calcium / Q000097:blood; D012080:Chronic Kidney Disease-Mineral and Bone Disorder / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications*; D008297:Male; D008875:Middle Aged; D015675:Osteocalcin / Q000097:blood; D010281:Parathyroid Hormone / Q000097:blood; D012372:ROC Curve; D006435:Renal Dialysis; D012680:Sensitivity and Specificity
D015415:Biomarkers; D010281:Parathyroid Hormone; D015675:Osteocalcin; D000469:Alkaline Phosphatase; D002118:Calcium