Frequency of familial hyperaldosteronism type 1 in a hypertensive pediatric population: clinical and biochemical presentation.

Familial hyperaldosteronism type 1 is an autosomal dominant disorder attributed to a chimeric CYP11B1/CYP11B2 gene (CG). Its prevalence and manifestation in the pediatric population has not been established. We aimed to investigate the prevalence of familial hyperaldosteronism type 1 in Chilean hypertensive children and to describe their clinical and biochemical characteristics. We studied 130 untreated hypertensive children (4 to 16 years old). Blood samples for measuring plasma potassium, serum aldosterone, plasma renin activity, aldosterone/renin ratio, and DNA were collected. The detection of CG was performed using long-extension PCR. We found 4 (3.08%) of 130 children with CG who belonged to 4 unrelated families. The 4 patients with CG had very high aldosterone/renin ratio (49 to 242). In addition, we found 4 children and 5 adults who were affected among 21 first-degree relatives. Of the 8 affected children, 6 presented severe hypertension, 1 presented prehypertension, and 1 presented normotension. High serum aldosterone levels (>17.7 ng/dL) were detected in 6 of 8 subjects (range: 18.6 to 48.4 ng/dL) and suppressed plasma renin activity (≤0.5 ng/mL per hour) and high aldosterone/renin ratio (>10) in 8 of 8 children (range: 49 to 242). Hypokalemia was observed in only 1 of 8 children. We demonstrated that the prevalence of familial hyperaldosteronism type 1 in a pediatric hypertensive pediatric population was surprisingly high. We found a high variability in the clinical and biochemical characteristics of the affected patients, which suggests that familial hyperaldosteronism type 1 is a heterogeneous disease with a wide spectrum of presentations even within the same family group.

Effect of 1,25(OH)2-vitamin D on bone mass in children with acute lymphoblastic leukemia.

BACKGROUND: Calcitriol deficit has been described in patients with acute lymphoblast leukemia (ALL). The aim of this randomized case-control trial is to investigate the effectiveness of calcitriol administration during the first year of treatment to protect bone mass. Sixteen children recently diagnosed with ALL, aged 1.7 to 11.5 years, average 5.5, completed the study. Anthropometrical measurements, food intake record, physical activity, and bone pain were registered. Dual energy x-ray absorptiometry was performed at the completion of remission induction chemotherapy (after 1 mo) to measure bone mineral density (BMD) at hip, lumbar spine and whole body, and total bone mineral content and 1 year after. Half of them were randomly assigned to receive calcitriol during 1 year. STATISTICAL: Kruskal-Wallis, Wilcoxon, Mann-Whitney, and Spearman. RESULTS: Both groups had similar anthropometric measurements and bone densitometric variables increments. Spine BMD significantly increased in calcitriol supplemented children with lower baseline BMD (r=-0.78 and P<0.05). CONCLUSIONS: One-year calcitriol administered to recently diagnosed ALL children did not show impact on bone mass. Greater increment in lumbar spine bone mass was observed in patients who received calcitriol and had lower baseline BMD.

Normalización de la densidad mineral ósea en niños nacidos prematuros en Viña del Mar, Chile / Normalization of bone mineral density in premature-born children from Viña del Mar, Chile

Background: In a previous study we reported that healthy children born at 34 or fewer gestational weeks, with adequate weight for gestational age, had not completed their bone catch-up at mean age of 6.3 years. Aim: This is a follow up report, performed on the same population one year later to determine at which age premature - born children achieve their bone mineral density (BMD) catch-up, compared to term-born controls. Material and methods: Fifteen children mean age 7years 3 months, born at 25 to 34 weeks of gestation, with a birth weight of 740 to 2.200 g were studied Radius, lumbar spine and femoral neck bone mineral density, whole body bone mineral content and body composition were assessed by DEXA. Results: Height, body mass index, peripheral BMD, axial BMD, fat and lean body mass in these children were not different from term born controls. Conclusions: Premature born children with adequate weight for gestational age, achieved peripheral and axial bone mineral density catch-up at the age of 7 to 8 years.

[Normalization of bone mineral density in premature-born children from Viña del Mar, Chile]. / Normalización de la densidad mineral ósea en niños nacidos prematuros en Viña del Mar, Chile.

BACKGROUND: In a previous study we reported that healthy children born at 34 or fewer gestational weeks, with adequate weight for gestational age, had not completed their bone catch-up at mean age of 6.3 years. AIM: This is a follow up report, performed on the same population one year later to determine at which age premature - born children achieve their bone mineral density (BMD) catch-up, compared to term-born controls. MATERIAL AND METHODS: Fifteen children mean age 7 years 3 months, born at 25 to 34 weeks of gestation, with a birth weight of 740 to 2.200 g were studied Radius, lumbar spine and femoral neck bone mineral density, whole body bone mineral content and body composition were assessed by DEXA. RESULTS: Height, body mass index, peripheral BMD, axial BMD, fat and lean body mass in these children were not different from term born controls. CONCLUSIONS: Premature born children with adequate weight for gestational age, achieved peripheral and axial bone mineral density catch-up at the age of 7 to 8 years.

[Acute suppurative thyroiditis. Report of a pediatric case]. / Tiroiditis aguda supurada en un paciente pediátrico.

Acute suppurative thyroiditis (AST) is an uncommon condition because thyroid gland is remarkably resistant to infections. In children, anatomic defects such as a left pyriform sinus fistula or a thyroglossal duct remnant predispose to this infection. Once the diagnosis is confirmed by ultrasound or computed tomography, antimicrobial therapy based on the culture and Gram staining must be started. After two or three weeks of treatment, predisposing anatomic defects must be sought cautiously. We report a 13 year old girl presenting with cervical pain and fever. A cervical ultrasound showed an enlarged thyroid lobule with hypoecogenic zones that suggested a supurative collection. Cefotaxime and cloxacillin were started. A needle aspiration of the collection obtained a purulent material. The culture of this material yielded a Streptococcus Pneumoniae. The clinical condition of the patient improved and she was discharged in good conditions. Two months later a contrast esophagus X ray did not show predisposing anatomic defects.

[Bone mineral density in school age children born preterm ]. / Densidad mineral ósea en escolares nacidos prematuros.

BACKGROUND: The age at which children born preterm normalize their bone mineral density, is not well known. AIM: To study if children born preterm have normalized their bone mineral density at age 5 to 7 years. PATIENTS AND METHODS: Twenty six infants born preterm (14 male), were studied at age 5 to 7 years. Birth weight, present weight and height, bone age, calcium and phosphate intake at the first year of life and at the current age were assessed. Bone mineral density was measured by single photon X ray absorptiometry in the dominant forearm. A blood sample was obtained to measure insulin growth factor 1 (IGF-1). As a control group, 105 healthy age-paired infants born at term, were studied. RESULTS: Bone mineral density was significantly lower in infants born preterm than in their term counterparts (0.273 +/- 0.01 g/cm2 and 0.302 +/- 0.01 g/cm2 respectively, p < 0.001). There was a positive correlation between bone mineral density and IGF-1 (r = 0.49, p = 0.01). No correlation with the other measured parameters was observed. CONCLUSIONS: Infants that were born preterm have a lower bone mineral density at 5 to 7 years of age than their term controls. Bone mineral density correlates with IGF-1.