Browsing by Author "Reyes, Maria Loreto"

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    Osteoporosis in children with severe congenital neutropenia: Bone mineral density and treatment with bisphosphonates
    (LIPPINCOTT WILLIAMS & WILKINS, 2006) Borzutzky, Arturo; Reyes, Maria Loreto; Figueroa, Valeria; Garcia, Cristian; Cavieres, Mirta
    A high incidence of decreased bone mineral density (BMD) has been described in patients with severe congenital neutropenia (SCN). The objectives of the study are to describe changes in BMD in children with SCN treated with granulocyte colony-stimulating factor and evaluate the response to treatment with bisphosphonates in those two had osteoporosis. A prospective open-label study was performed evaluating BMD and metabolism in 9 Chilean patients with SCN, administrating bisphosphonates in those with osteoporosis. Follow-up ranged between 7 months and 3.5 years. Six out of 9 patients had reduced BMD on initial assessment: 3 had osteoporosis (z score < - 2) and 3, had osteopenia (z score < - 1). Four children presented vertebral fractures. Two presented osteopenia on follow-up without Clinical Symptoms. Five patients were treated with biphosphonates, increasing their BMD z Score (mean increase 1.2. range 0.27 to 2.62). z Score of hydroxyproline/ creatinine ratios, which was elevated in 4 patients with osteoperosis, decreases during treatment (mean decrease 2.18, range 1.56 to 2.53). Four patients remodeled and reexpanded fractured vertebrae during treatment. No side effects of bisphosphonate were seen on follow-up. Osteoporosis is an important comorbidity in SCN patients probably due to an increased bone resorption. Bisphosphonates seem to be an effective treatment for osteoporosis in these patients.
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    Weekly Vitamin D Supplementation to Prevent Acute Respiratory Infections in Young Children at Different Latitudes: A Randomized Controlled Trial
    (2024) Reyes, Maria Loreto; Vizcaya, Cecilia; Le Roy, Catalina; Loureiro, Carolina; Brinkmann, Karin; Campos, Laura; Arancibia, Monica; Iturriaga, Carolina; Perez-Mateluna, Guillermo; Rojas-McKenzie, Maite; Dominguez, Gonzalo; Camargo Jr, Carlos A.; Borzutzky, Arturo
    Objective: To evaluate the effectiveness of weekly vitamin D supplementation in reducing the number of acute respiratory infections (ARI) in preschool children. Study design: Randomized, double-blind, placebo-controlled trial in 303 children aged 1.5-3.5 years from 2014 to 2105 in 3 Chilean cities at different latitudes: Santiago (33 degrees S, n = 101), Talcahuano (37 degrees S, n = 103), and Punta Arenas (53 degrees S, n = 99). Participants were allocated (1:1:1) to receive placebo, cholecalciferol (vitamin D3 (VD3)) 5600 IU/week (low-dose), or 11 200 IU/week (high-dose) for 6 months. Primary outcome was parent-reported number of ARI; secondary outcomes included number of ARI hospitalizations, change of serum 25-hydroxyvitamin D (25(OH)D) and LL-37/cathelicidin levels, and adverse events. Results: The mean age of participants was 26 +/- 6 months; 45% were female. Baseline 25(OH)D was 24.9 +/- 6.1 ng/ml, with 23% having 25(OH)D <20 ng/ml. No significant baseline clinical or laboratory differences were observed among groups. Overall, 64% (n = 194) completed study participation, without baseline differences between subjects lost to follow-up vs those completing participation or differences in completion rates across groups. After 6 months, a dose-dependent increase in serum 25(OH)D was observed from the VD3 intervention (P < .001), with a higher proportion of subjects ending the trial with 25(OH)D <20 ng/ml in the placebo group (30.8%) vs the low-dose (7.4%) and high-dose groups (5.1%). However, no group differences were observed in number of ARI (P = .85), ARI hospitalizations (P = .20), LL-37/cathelicidin change (P = .30), or adverse events (P = .41). Conclusions: While weekly VD3 supplementation, in doses equivalent to 800 IU and 1600 IU daily, was associated with improved 25(OH)D levels in preschoolers, we did not find a reduced number of ARI in this sample.