CW NG1, SD YAP2, R RAJ3, M MATHEW3
1Peninsula Health, Frankston, Victoria; 2Alfred Health, Melbourne, Victoria; 3Launceston General Hospital, Launceston, Tasmania
Aim: This study investigated cholecalciferol’s efficacy in maintaining serum calcium in adult dialysis dependent chronic kidney disease patients.
Background: Dialysis dependent chronic kidney disease patients have reduced renal 1-α-hydroxylase and consequently insufficient active vitamin D activity, which is often manifested as hypocalcaemia. Calcitriol is traditionally used as not needing further renal conversion. However, it can cause increased phosphate absorption from gut. There is evidence of persistent extra-renal 1-α-hydroxylase activity in these patients. Hence, cholecalciferol has been proposed as potential alternative therapy.
Methods: This twelve-week pilot prospective interventional cohort study was conducted across three dialysis units in Tasmania. Adult dialysis patients on pre-existing calcitriol and normal serum calcium were enrolled. Their calcitriol was then changed to cholecalciferol. Bloods including calcium, phosphate, parathyroid hormone, alkaline phosphatase, 25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 were sampled at baseline, 4-week, 8-week and 12-week post therapy change. Therapy success was defined as ability of cholecalciferol to maintain serum calcium, and the successful proportion was calculated.
Results: From February till April 2016, 112 patients were screened and total 13 patients were enrolled. 12 of 13 participants succeeded cholecalciferol therapy at end of study. When compared to baseline, there was no significant difference to serum calcium, phosphate and parathyroid hormone at end of study. There was statistically significant rise in serum alkaline phosphatase (mean increase 19.1 U/L, P=0.004) and 25-hydroxyvitamin D3 (mean increase 24.7 nmol/L, P<0.001) at week 12. Serum 1,25-dihydroxyvitamin D3 showed significant initial drop at week 4 (mean reduction 28.1 pmol/L, P<0.001) and week 8 (mean reduction 20.2 pmol/L, P<0.001), but exhibited no significant difference by week 12.
Conclusions: Cholecalciferol can maintain serum calcium in adult chronic kidney disease patients on dialysis.