Saudi Journal of Kidney Diseases and Transplantation

ORIGINAL ARTICLE
Year
: 2011  |  Volume : 22  |  Issue : 3  |  Page : 428--432

Evaluation of growth and body mass index in children following kidney transplantation


N Derakhshan1, A Derakhshan2, MH Fallahzadeh2, M Basiratnia3, MK Fallahzadeh1, D Derakhshan1, SA Malekhosseini4,  
1 Shiraz Nephro-Urology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
2 Shiraz Nephro-Urology Research Center, Shiraz University of Medical Sciences, Shiraz; Pediatric Nephrology Department, Namazi Hospital, Shiraz, Iran
3 Pediatric Nephrology Department, Namazi Hospital, Shiraz, Iran
4 Shiraz Organ Transplant Research Center, Shiraz University of Medical Sciences, Shiraz, Iran

Correspondence Address:
N Derakhshan
71937-Pediatric Section, Namazi Hospital, Shiraz
Iran

Abstract

Growth retardation is common among children with chronic kidney disease (CKD). Renal transplantation has beneficial effects on height and weight gain of children, but height gain occurs especially for those children who are transplanted at a younger age. This study was conducted for a cross-sectional evaluation of growth and body mass index (BMI) in children following kidney transplantation. All children who had been transplanted in our center and had regular follow-up were entered in this study. Those with primary non-functioning grafts were excluded from the study. Weight and height at transplantation and at 20 years of age or at a pre-determined period (1-4-2008 to 30-6-2008) were recorded. Their height, weight, BMI, standard deviation score (SDS) of height and weight at their pre- and post-transplantation period were compared. SPSS 15.1 software and paired t-test were used for comparison of means. Seventy-one children, 43 boys and 28 girls, were involved in this study. The mean age at transplantation was 12.6 ± 3.45 years, ranging from 3 to 19 years, and age at last visit was 16.9 ± 3.15 years. They had been followed-up for 7-175 months (mean, 51.6 ± 30.75 months). Their primary renal diseases were as follows: reflux, obstruction and dysplasia 29 (41%), hereditary 25 (35%), glomerular disease 14 (20%), unknown 3 (4%). Source of donor was living related in 27 (38%), with 15 being mothers, deceased in 35 (49%) and living unrelated in 9 (13%). SDS height improved dramatically in post-transplantation evaluation, but this did not happen for SDS weight and BMI. We can conclude that despite a dramatic effect of transplantation on growth, catch-up growth only occurred in a minority of the children.



How to cite this article:
Derakhshan N, Derakhshan A, Fallahzadeh M H, Basiratnia M, Fallahzadeh M K, Derakhshan D, Malekhosseini S A. Evaluation of growth and body mass index in children following kidney transplantation.Saudi J Kidney Dis Transpl 2011;22:428-432


How to cite this URL:
Derakhshan N, Derakhshan A, Fallahzadeh M H, Basiratnia M, Fallahzadeh M K, Derakhshan D, Malekhosseini S A. Evaluation of growth and body mass index in children following kidney transplantation. Saudi J Kidney Dis Transpl [serial online] 2011 [cited 2020 Jul 10 ];22:428-432
Available from: http://www.sjkdt.org/text.asp?2011/22/3/428/80475


Full Text

 Introduction



Children with chronic kidney disease (CKD) are often growth retarded, and growth retardation is more obvious in younger children. Growth retardation begins from the early phases of CKD. Failure to thrive in these children is multifactorial and related to inadequate intake, renal osteodystrophy, metabolic acidosis, anemia and, eventually, growth hormone resistance, which appears to be the most important factor. [1],[2],[3],[4],[5]

Although there is a dramatic improvement in most of the pre-transplant metabolic derangements, growth is suboptimal following successful kidney transplantation. Children who are transplanted at a younger age (<7 years) show better growth than children who are transplanted at older ages, and the younger group may have catch-up growth. [6],[7] In the recent transplant era, final height of children is better and is mostly dependent on the pre-transplant treatment. [8] Steroids that are used in most transplant regimens is an important inhibitor of growth, and children on steroid-free protocols or alternate-day prednisolone have better growth. [9],[10],[11]

On the other hand, children have a significant weight gain following transplantation, and this happens especially during the first year of transplantation when recipients are on higher doses of steroids. [8],[12] Obesity may have a deleterious effect on graft survival, although this has not been confirmed in all studies. [13],[14],[15],[16] Despite the importance of growth and, especially, body mass index (BMI) in children, there are limited reports. This study was conducted as a cross-sectional evaluation of growth and BMI following kidney transplantation in children.

 Method



This study was designed as a cross-sectional evaluation of weight, height and BMI and standard deviation score (SDS) of height and weight. All children or adults who have been transplanted in our center are referred to their primary physician for routine laboratory evaluation and prescription of their transplant medication at 3-month intervals. Our colleagues were requested to measure and record weight and height during a specific 3-month period (1-4-2008 to 30-6-2008).

All children who were transplanted at our center from the beginning of transplant activity and were ≤19 years at the time of transplantation with a functioning graft at the time of evaluation were included in this study. For children who were older than 20 years at the time of evaluation, data at the age of 20 years were considered for calculations. Height and weight data at the time of transplantation were obtained from their medical files and also weight and height at their last visit were measured and recorded by their responsible physician during the 3-month period. Children with primary non-functioning grafts and those who expired and those with irregular follow-up or incomplete data were excluded from the study. BMI was calculated using the following equation: BMI = weight (kg) / (height (m 2 ).

The Center for Disease Control (CDC) growth charts and The National Health and Nutrition Examination Survey (NHANES) analytic and reporting guidelines 2006 were used for determination of SDS of height and weight.

SPSS 15.1 software and paired t-test were used for comparing the means of the pre- and post-transplant weight, height, BMI, SDS of height and weight. P value <0.05 was considered significant.

 Results



Seventy-one children, 43 (58.9%) boys and 28 (41.1%) girls, were involved in this study. The pre- and post-transplantation values for height, weight, BMI and SDS are summarized in [Table 1]. Their primary renal diseases were as follows: reflux, obstruction and dysplasia 29 (41%), hereditary 25 (35%), glomerular disease 14 (20%) and unknown 3 (4%). They had been followed from 7-175 months (mean, 51.6 ± 30.75 months). The source of donors were as follows: living related 27 (38%), with 15 being mothers, deceased 35 (49%) and living unrelated 9 (13%).{Table 1}

Induction immunosuppression consisted of methyl-prednisolone pulse therapy 30 mg/kg (maximum 1000 mg) on days 1 to 3, followed by cyclosporine, oral prednisolone and mycophenolate mofetil (MMF). Fourteen patients who had been transplanted during earlier period were on azathioprine instead of MM. Mean cyclosporine dose at the time of evaluation was 3.52 ± 1.2 mg/kg (range, 0.8-6.4 mg/kg), with an acceptable blood level. The lowest dose belonged to an overweight girl with Bardet- Biedl syndrome. One patient with initial hemolytic uremic syndrome was on double therapy with prednisolone and MMF and another patient and another patient who had received the kidney from his brother had discontinued all of his medication in the 2 nd year of transplantation without any significant consequence. Mean prednisolone dose was 0.09 ± 0.07 mg/kg (range, 0.02-0.33 mg/kg). Serum creatinine ranged from 0.5 to 3 mg%, with a mean of 1.15 ± 0.46 mg/dL.

SDS of the values of heights at the time of transplantation are compared with the post-transplantation values [Figure 1], which was statistically significant (P= 0.0003). These values [Figure 2] were not significant for weight (P> 0.05). As seen in [Figure 2], catch-up growth occurred only in a few patients at the time of evaluation in the post-transplantation period.{Figure 1}{Figure 2}

 Discussion



Growth retardation is an almost uniform finding in children with CKD. Growth retardation begins from the early phases of CKD and is related to different factors, including low-calorie intake, metabolic acidosis, anemia, renal osteodystrophy and growth hormone resistance. [1],[2],[3],[4],[5]

Seventy-one children were evaluated at a mean period of five years after renal transplantation. The SDS of their mean height, weight and also their BMI at the time of transplantation were compared with their post-transplantation values. At the time of transplantation, the majority were below the 3 rd percentile of height and weight, as has been observed in other studies. [1],[2],[3],[4],[5] In their post-transplantation evaluation, SDS for height had a significant improvement, as has been seen in other studies. [6],[7],[8] The improved growth that was observed after transplantation was mainly due to a significant height gain of children who were transplanted below 11 years of age. SDS of post-transplantation weight was not significantly different from the pre-transplant values. Lack of significant weight gain was mainly due to a longer period elapsed from transplantation, since post-transplantation weight gain occurs mainly during the first year of transplantation when they are taking the highest dose of steroids. [8] At the time of evaluation, these children were on a very low dose of steroids on alternate days. They may have had a stationary weight or minimal weight gain for a long time after the first year of transplantation.

We took the age of 20 years for ease of calculations as the reference values in the pediatric literature includes up to 20 years. Poor nutrition may be a reason for this finding in our patients in comparison with other studies. As has been noticed by Rogers et al [12] and el-Agroudy, [13] post-transplantation BMI is influenced by pre-transplant BMI, and because our patients had a low BMI at the time of transplantation, this may have affected the post-transplant weight gain. In our study a vast majority of children had normally functioning grafts and therefore, renal dysfunction cannot be the reason for the lack of significant weight gain in the post-transplantation period. Kidney transplantation had a dramatic effect on height gain in children, but weight gain was less satisfactory. This study had the limitation that it was cross-sectional and the post-transplantation evaluation was performed only once and at different time intervals from transplantation.

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