Interleukine 6 and C-reactive protein predict growth impairment and acute malnutrition in children and adolescents with chronic kidney disease

Objective: secondary malnutrition and systemic inflammation may impair growth and body composition in children and adolescents with chronic kidney disease (CKD). This association has been scantily studied, particularly in pre-dialytic stages. Our aim was to correlate growth and nutritional status indicators with the serum concentration of interleukine 6 (IL-6) and ultrasensitive C-reactive protein (CRP) in children with CKD. Methods: this was a prospective cross-sectional study in 29 children and adolescents aged 3-16 years with CKD, stages 3 or 4, in two third-level general hospitals. The outcome variables were height for age, body mass index, arm anthropometric indicators, plus lean mass/fat percentage by bioelectrical impedance. The independent variables were IL-6 and CRP. This study was reviewed and approved by the Health Research and Ethics Committees of both hospitals. Results: height for age, body mass index, subscapular skinfold, arm fat area, and lean mass had a significant negative correlation with IL-6. The height-for-age z-score had a negative correlation with CRP. IL-6 explained 15% to 35% of the variance in height for age and nutritional status indicators. CRP predicted 22% of height for age. One fifth of the patients had acute malnutrition, and one third were stunted. Muscle was the most affected compartment. Conclusion: IL-6 and CRP in children and adolescents with CKD in the pre-dialytic stage predicted one fifth and one third of the variance in acute and chronic malnutrition indicators. The frequency of acute malnutrition and impaired growth was clinically significant. Muscular mass deficit was a central component of malnutrition.