Biochemical indices of renal osteodystrophy in dialysis patients on the island of Malta.
OBJECTIVE
Renal osteodystrophy (ROD) has never been studied on the small Mediterranean island of Malta, which has a largely inbred population. The genetic contribution to the pattern of renal osteodystrophy is being increasingly recognized. We were, thus, interested in studying indices of bone turnover in Maltese end stage renal failure patients.


METHODS
Sixty unselected patients, representing 65% of all patients undergoing dialysis in the island's renal unit, were prospectively investigated over a period of 5 months with respect to symptoms, calcium/phosphate chemistry, intact parathyroid hormone (iPTH) and bone alkaline phosphatase (bAP). Bone histomorphometry, which is the gold standard in the diagnosis of ROD, was not within the reach of our small unit. Biochemical markers may not be as sensitive and specific as bone biopsy for individual patient diagnosis of ROD sub-type but they can give a fairly good indication of the spectrum of bone turnover on a population basis. The optimum combination of biochemical marker cut-offs available from studies in the literature was then employed to estimate bone turnover.


RESULTS
The following biochemical picture emerged: 42% had iPTH < 79.7 pg/ml (which cut off has a reported specificity of 93.7% for low turnover bone disease), 45% had iPTH > 100 pg/ml and bAP > 10 ng/ml (which combined cut off has a reported specificity of 100% for high turnover bone disease), while 13% could not be classified (ie had intermediate values).


CONCLUSIONS
Based on biochemical data, the pattern of bone turnover seems to be comparable to the European average. Further indepth study using bone histomorphometry is warranted.
Galea
Ian
I
Ian Galea, Department of Medicine, St. Luke's Hospital, Malta.
Farrugia
Emanuel
E
D000469:Alkaline Phosphatase / Q000097:blood*; D001842:Bone and Bones / Q000378:metabolism; D012080:Chronic Kidney Disease-Mineral and Bone Disorder / Q000097:blood* / Q000378:metabolism; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood / Q000378:metabolism; D008297:Male; D008319:Malta; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood*; D011446:Prospective Studies
D010281:Parathyroid Hormone; D000469:Alkaline Phosphatase