ABSTRACT
Resumen: Introducción: Los métodos de referencia para cuantificar la tasa de filtración glomerular (TFG) son poco accesibles en la práctica clínica. Para evaluar la TFG se utilizan fórmulas basadas en la creatinina sérica y/o aclaramiento de creatinina. El objetivo de este estudio fue cuantificar la correlación y concordancia de la TFG con depuración de creatinina en orina de 24 horas (TFG24) y fórmulas de Schwartz y Schwartz actualizada. Métodos: Estudio transversal analítico que incluyó pacientes de 5 a 16.9 años, sanos y con enfermedad renal crónica. Se evaluó la relación lineal entre la TFG24 y ambas fórmulas con el coeficiente de correlación de Pearson (r) y la concordancia con el coeficiente de correlación intraclase (CCI). Resultados: Se estudiaron 134 pacientes, 59.7% de género masculino, la edad promedio fue 10.8 años. La TFG24 promedio fue 140.34 ml/min/1.73 m2; el 34.3% (n = 46) presentaron TFG < 90 ml/min/1.73 m2. Se observó moderada relación lineal entre la TFG24 y las fórmulas de Schwartz (r= 0.63) y Schwartz actualizada (r= 0.65). Hubo buena concordancia entre la TFG24 y fórmula de Schwartz (CCI= 0.77) y de Schwartz actualizada (CCI= 0.77). En pacientes con TFG24 ≥ 90 ml/min/1.73 m2 la fórmula de Schwartz clásica estimó valores mayores de TFG, mientras que Schwartz actualizada subestimó los valores. Conclusiones: Existe moderada correlación y buena concordancia entre la TFG24 y fórmulas de Schwartz y Schwartz actualizada. Con ambas fórmulas la concordancia fue mayor en pacientes con obesidad y menor en mujeres, pacientes con hiperfiltración y con peso normal.
Abstract: Background: Reference methods for the quantification of the glomerular filtration rate (GFR) are difficult to use in clinical practice; formulas for evaluating GFR based on serum creatinine (SCr) and/or creatinine clearance are used. The aim of this study was to quantify the correlation and concordance of GFR with creatinine clearance in 24-hour urine (GFR24) and Schwartz and Schwartz updated formulas. Methods: Cross-sectional study involving healthy pediatric patients and with chronic kidney disease (CKD) from 5 to 16.9 years. Linear correlation between GFR 24 and two formulas was evaluated with the Pearson correlation coefficient (r) and intraclass correlation coefficient (ICC). Results: We studied 134 patients, of which 59.7% were male. Mean age was 10.8 years. The average GFR24 was 140.34 ml/min/1.73 m2; 34.3% (n = 46) had GFR <90 ml/min/1.73 m2. Moderate linear correlation between GFR24 and Schwartz (r= 0.63) and Schwartz updated (r= 0.65) formulas was observed. There was good concordance between the GFR24 and Schwartz (ICC= 0.77) and updated Schwartz (ICC= 0.77) formulas. Schwartz classical formula in patients with GFR24 ≥ 90 ml/min/1.73 m2 estimated higher values, while Schwartz updated underestimated values. Conclusions: There is moderate correlation and good concordance between the GFR24 and Schwartz and Schwartz updated formulas. The concordance was better in patients with obesity and lower in women, patients with hyperfiltration and normal weight.
ABSTRACT
OBJECTIVE: To determine the prevalence of upper and lower neural tube defects and identify its association with the exposure to illnesses and drugs during pregnancy. MATERIAL AND METHODS: This is a case-control study of 107 newborns with upper neural tube defects, 59 with lower neural tube defects, and 166 newborns without malformations, in 56,926 consecutive births between 1989 and 1997. The exposure was documented by a direct interview to the mother of those subject of study. The association was measured by the odds ratios, with confidence interval of 95. RESULTS: The prevalence of upper neural tube defects was of 1.9 for 1,000 newborn (alive or dead) and of lower neural tube defects of 1.0 for 1,000. The exposure to illnesses of less than a month of duration was associated with upper neural tube defects (OR = 3.11; IC = 1.34-7.39) the most important was flu; also the exposure to drugs (OR = 5.85; IC = 2.97-11.62), the most prominent was acetaminophen. These factors of risk were not associated with lower neural tube defects. The mother's occupation, illness of more than a month of duration and X-ray exposure were not associated with of upper and lower neural tube defects. CONCLUSIONS: More studies are needed in the association among illnesses of less than a month of duration and drugs with upper neural tube defects. The different exposure frequencies between upper and lower neural tube defects suggest heterogeneity.