ORIGINAL ARTICLE Bicarbonate therapy improves growth in children with incomplete distal renal tubular acidosis Ajay P. Sharma & Ram N. Singh & Connie Yang & Raj K. Sharma & Rakesh Kapoor & Guido Filler Received: 8 December 2008 / Revised: 2 March 2009 / Accepted: 3 March 2009 / Published online: 4 April 2009 # IPNA 2009 Abstract Incomplete distal renal tubular acidosis (idRTA) has recently been associated with osteoporosis and growth retardation, attributed to the mild persistent metabolic acidosis. We hypothesized a therapeutic benefit from bicarbonate therapy on growth parameters in children with idRTA. In a study group of 40 surgically treated patients with posterior urethral valve (PUV) and normal estimated glomerular filtration rate, we evaluated the change in height standard deviation scores (SDSs) while they were on bicarbonate therapy in the presence of idRTA and complete distal renal tubular acidosis (dRTA). Age- and gender- matched healthy subjects constituted the control group (n = 55). Incomplete dRTA was evaluated by ammonium chloride acidification. The baseline height SDS of -1.94± 0.41 and -5.31±1.95 in the groups with idRTA and complete dRTA, respectively, were significantly lower than that of the controls. After a follow-up period of 24.7± 8.3 months on sodium bicarbonate therapy, the idRTA patients had a 66% increase in height SDS compared with 26% and 3% increases in the patients with PUV with complete dRTA and without dRTA, respectively. At the end of follow-up, mean height SDS in the group with idRTA no longer remained significantly lower than that of the controls (P=0.42). We concluded that bicarbonate therapy improves height SDS in idRTA. This issue needs further validation in larger studies. Keywords Growth . Height . Renal tubular acidosis . Bicarbonate . Stature Abbreviations RTA renal tubular acidosis dRTA distal renal tubular acidosis idRTA incomplete dRTA SDS standard deviation score PUV posterior urethral valves CKD chronic kidney disease eGFR estimated glomerular filtration rate VUR vesicoureteric reflux VBG venous blood gas FeNa fractional excretion of urinary sodium Δ Height SDS the difference between the height SDS at the end of the follow-up period and the baseline height SDS in the groups with dRTA Δ Height difference the difference between the height SDS at the end of the follow-up period in the groups with dRTA and their respective controls PTH parathyroid hormone Pediatr Nephrol (2009) 24:1509–1516 DOI 10.1007/s00467-009-1169-y A. P. Sharma (*) : G. Filler Department of Pediatrics, Division of Nephrology, University of Western Ontario, 800, Commissioner’ s Road E, Children’ s Hospital, London Health Sciences Centre, London, ON N6A 5W9, Canada e-mail: ajay.sharma@lhsc.on.ca R. N. Singh Department of Pediatrics, Division of Critical Care Medicine, University of Western Ontario, London, ON, Canada C. Yang Department of Pediatrics, University of Western Ontario, London, ON, Canada R. K. Sharma Department of Nephrology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India R. Kapoor Department of Urology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India