Variáveis clínicas e bioquímicas associadas com a evolução do peso e da estatura de crianças e adolescentes com doença renal crônica em tratamento conservador

Abstract

The purpose of this study was to evaluate the evolution of anthropometric parameters of children and adolescents with chronic kidney disease (CKD) in conservative treatment. Measurements of weight, stature and biochemical tests of 138 patients whose ages vary from 0 to 19 years old collected at the first and the last nutritional consultation, from 1990 to 2008, were retrospectively analyzed. The CKD stage was classified according to the estimated glomerular filtration rate, and the primary renal disease was classified in four categories: Congenital Nephrouropathy, Glomerular Disease, Cystic Disease and Others. The statistical analysis was based on the presentation of descriptive data, summary measures like mean and standard deviation (SD), besides the percentage distribution of categorical variables. The paired t-test was used to compare nutritional data at the admission and at the end of the follow-up. In this study, we focused on two main outcomes: body mass index (BMI)-for-age and stature-for-age Z scores, obtained at admission and at last visit, and evaluated according to the World Health Organization (WHO) guidelines. There was a predominance of males (55.8%) and the median age at admission was 9 years. The median follow-up time was 5 years and 5 months. The most frequent category of primary renal disease was Congenital Nephrouropathy (58%) and most of the cohort was classified in the stage 3 of CKD (53.6%). The relation between the initial and final BMI scores Z did not show significant difference. The stratified analyses showed a significant improvement in BMI score Z, especially in the subgroup of children who entered the study with less than two years old (p=0,001). Regarding the CKD staging at the admission, there was a significant difference in average BMI scores Z among the three groups (p=0.032). However, the same difference was not seen in the end of the study (p=0.203). Concerning the stature-for-age score Z, the data show a significant improvement of the stature SD in the end of the study. The average initial stature-for-age score Z was -2.15 ± 1.46, which is low according to the WHO guidelines, and the final was -1.82 ± 1.49 (p=0.001). With respect to primary renal disease, it was not observed significant difference between the mean initial stature scores Z (p=0.24) and between the mean final stature scores Z (p=0.32) of the four groups. The logistic regression analysis indicated a significant association between the stature score Z at admission and initial albumin. The analysis demonstrated that each 1 SD increase in initial stature score Z increases by four times the chance of achieving the appropriate stature score Z (p=0.001) and each increase in 1 gram in initial albumin increases by 2 times the chance of reaching for an adequate stature in the end of the study (p=0.012). These results reinforces the statement that the children and adolescents growth impairment is multifactorial, presenting its relation with the age at CKD onset and etiology, and with nutritional and metabolic management. Thus, the regular multiprofessional care is a key component of global management of children and adolescents with CKD.