Low-calcium dialysate improves mineral metabolism in hemodialysis patients.
BACKGROUND
The Kidney Disease Outcomes Quality Initiative (K/DOQI) Guidelines for Bone Metabolism and Disease in Chronic Kidney Disease recommend 1.25 mmol/l Ca dialysate for both hemodialysis and peritoneal dialysis, while 1.5 mmol/l Ca dialysate has been used in our dialysis center.


METHODS
Therefore, we switched the dialysate calcium concentration from 1.5 - 1.25 mmol/l and observed the effects on serum calcium (S-Ca), phosphorus (S-P), 1-84 parathyroid hormone (whole PTH, w-PTH), bone-specific alkaline phosphatase (BAP), and tartrate-resistant acid phosphatase isoform 5b (TRACP-5b) for 6 months in 58 hemodialysis patients. Prescription of active vitamin D (VD) metabolites and Ca carbonate was increased in response to the changes in laboratory data.


RESULTS
Decrease of S-Ca was evident at 2 weeks and S-Ca remained low for 6 months. Transient elevation of S-P, which might be caused by stimulated bone resorption, was observed after the switch. In patients with low PTH (w-PTH less than 90 pg/ml before the switch), continuous increase of w-PTH, BAP, and TRACP-5b was observed. This appeared to be a favorable response because the risk ofadynamic bone disease was high in this group of patients. On the other hand, acute elevation of the 3 parameters was well-controlled in patients with moderate and high PTH (w-PTH from 90 - 180 pg/ml, w-PTH more than 180 pg/ml, respectively) by increased dosage of active VD.


CONCLUSIONS
These results demonstrate that 1.25 mmol/l Ca dialysate improved mineral metabolism by lowering S-Ca and releasing oversuppression of PTH. Our data also suggest that appropriate use of active VD could prevent acute rise of PTH.
Fujimori
A
A
Department of Artificial Kidney, Konan Hospital, 1-5-16 Kamokogahara, Higashinada-ku, Kobe 658-0064, Japan. louie@kcc.zaq.ne.jp
Yorifuji
M
M
Sakai
M
M
Oyama
M
M
Nakao
N
N
Tokuyama
M
M
Fukagawa
M
M
D000135:Acid Phosphatase / Q000097:blood; D000368:Aged; D000469:Alkaline Phosphatase / Q000097:blood; D002118:Calcium / Q000008:administration & dosage* / Q000097:blood*; D005260:Female; D015312:Hemodialysis Solutions / Q000737:chemistry*; D006801:Humans; D007527:Isoenzymes / Q000097:blood; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood; D010758:Phosphorus / Q000097:blood*; D006435:Renal Dialysis; D000071681:Tartrate-Resistant Acid Phosphatase
D015312:Hemodialysis Solutions; D007527:Isoenzymes; D010281:Parathyroid Hormone; D010758:Phosphorus; D000469:Alkaline Phosphatase; C000605510:ACP5 protein, human; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase; D002118:Calcium