Bone mineral density in children with steroid-sensitive nephrotic syndrome.

Objective. To observe the influence of prednisolone treatment on bone mineral density (BMD) in children with idiopathic nephrotic syndrome. Methods. Duel-energy X-ray absorptiometry of lumbar spine (L1-L4) was performed on 40 patients (18 first episode and 22 relapsers) of steroid sensitive idiopathic nephrotic syndrome. Results. Patients of first episode and relapsers had comparable values of mean age, weight, height, body mass index, serum calcium, phosphate, spine area, bone mineral content (BMC) and BMD. Relapsing nephrotic syndrome patients received significantly higher mean total cumulative dose of prednisolone in comparison to first episode (p<0.001). The BMD Z-scores were normal in 39 of 40 (97.5%) patients. On regression analysis, it was found that both BMC and BMD did not correlate with cumulative dose of prednisolone, when other co-variants such as age, weight, height and spine area were adjusted. Conclusion. Bone mineral density in steroid sensitive nephrotic syndrome is unaffected by cumulative dose of prednisolone therapy both in first episode as well as relapser group of patients.

Hipercalciuria idiopática y compromiso óseo en niños / Idiopathic hypercalciuria and bone injury in children

Introducción: la Hipercalciuria Idiopática (HI), entidad considerada tradicionalmente benigna y asociada a hematuria o urolitiasis, es uno de los trastornos del metabolismo de calcio y fósforo más frecuente en pediatría. En los últimos años se ha asociado a desmineralización ósea tanto en niños como en adultos. Objetivo: determinar el impacto de la Hipercalciuria Idiopática en el contenido mineral óseo en pacientes pediátricos chilenos. Métodos: estudio de corte transversal; se evaluaron 11 pacientes portadores de Hipercalciuria Idiopática. Se midió calcio en orina de 24 horas y en muestra aislada, calcemia, fosfemia, electrolitos plasmáticos, paratohormona plasmática (PTH) y densitometría ósea (DEXA) de columna lumbar y fémur. Para definir la relación entre la calciuria y las demás variables se utilizó un análisis de correlación simple para variables continuas. Se consideró estadísticamente significativo un p < 0,05. Resultados: se estudiaron 11 pacientes, 6 varones, 8,2 ± 2,7 años. El promedio de calcio en orina 24 h fue 9,1 ± 1,37 mg/kg/día, PTH 40 ± 15 pg/ml y el DEXA columna lumbar (Z score) fue de y -2,1 ± 0,29. El análisis estadístico mostró una correlación negativa entre calciuria de 24 h y densidad mineral ósea de columna lumbar (p < 0,05, r = -0,65), y entre Hipercalciuria vs niveles de PTH (p < 0,05, r = -0,58). Conclusión: la Hipercalciuria Idiopática en pediatría representa un riesgo de compromiso óseo que debe ser considerado al evaluar el manejo de cada paciente.

Hipovitaminosis D en mujeres postmenopáusicas con masa ósea baja en la Región Metropolitana / Vitamin D levels in postmenopausal women with low bone mineral density from Región Metropolitana

Background: Low vitamin D levels are a risk factor for osteoporosis. In the Northern hemisphere, a high frequency of low vitamin D levels has been detected. The correction of this deficit is associated with a lower fracture risk. Aim: To measure serum vitamin D levels in postmenopausal women with low bone mineral density. Material and methods: 25-hydroxyvitamin D levels were measured in 40 postmenopausal women aged 50 to 74 years old, with a spine bone mineral density of less than 2 standard deviation of the values for young individuals. Serum calcium, phosphorus and calcium dietary intake were also measured. Results: Mean serum 25-hydroxyvitamin D levels were 32.2 ñ 12.5 ng/ml. No correlation between vitamin D levels and other measured variables was observed. Using a cutoff value of 15 ng/ml, two women had low 25-hydroxyvitamin D levels. Conclusion: In this sample of postmenopausal women, vitamin D deficiency was infrequent