CORRELATION OF THE PROTEIN DETERMINATION IN 24-HOUR URINE WITH THE PROTEIN / CREATININE INDEX IN PEDIATRIC PATIENTS WHO GO TO THE EXTERNAL CONSULTATION OF THE PEDIATRIC NEPHROLOGY SERVICE AT THE NAVAL MEDICAL CENTER

Introduction : Proteinuria increases infant morbidity and mortality, constituting a risk for the development of chronic kidney disease. Medical follow-up is necessary to monitor kidney function, as well as to prevent long-term deterioration of kidney function. Proteinuria can be benign or a serious systemic disorder, the one that is persistent accelerates the decrease in the glomerular filtration rate and key in the progression of kidney diseases. There are various ways of measuring urinary proteins, between the protein / creatinine index and in 24-hour urine, which present a variable correlation according to what is described in the literature. Objective: To determine the correlation of 24-hour protein and protein / creatinine index in pediatric patients who attend the outpatient clinic of the pediatric nephrology service at the Naval Medical Center. Material and methods : Descriptive cross-sectional study. Performed in the Pediatric service and Pediatric Nephrology outpatient service at the Naval Medical Center. Study population: Children with a history of proteinuria treated by the Pediatric Nephrology service at the Naval Medical Center. General description of the study : The patients were selected from the electronic file that they attended the Pediatric Nephrology service. In the clinical evaluation, weight and height were taken, and a physical examination was performed, as well as a 24-hour protein determination in 24-hour urine, 24-hour creatinine clearance in urine in addition to creatinine and proteins in isolated urine. Statistical analysis : Descriptive statistics were performed, according to the measurement scale of the variables and the correlation between the variables was determined using the Spearman or Pearson test according to the type of distribution of the quantitative variables. Results : 107 were included. Taking into account the 24-hour urine collection protein measurement, only 4 patients (7.4%) presented proteinuria in nephrotic ranges and for the CPI measurement only 3 (5.6%). With both measurement methods, the same proportion of significant proteinuria was observed, corresponding to 13 patients (24.1%), obtaining in the first case a spearman correlation coefficient of r = 0.752, p = 0.000, and for the second an r = 0.911, p: 0.000. Conclusions: The protein / creatinine index had a positive correlation with 24-hour proteinuria in those pediatric patients who presented abnormal results in urine studies and kidney stones (32%), chronic kidney disease and kidney transplantation (18%) and obesity / overweight. Likewise it allows to establish a directly proportional association. There is a positive correlation between the protein / creatinine index and the quantification of proteinuria in 24 hours after adjusting for creatinine per kilogram of weight. And the protein / creatinine ratio is a good candidate for the diagnosis of chronic kidney disease in pediatric patients and its use is justified.