RESUMO
CONTEXT: The role of magnesium (Mg) as a determinant of bone mass has not been extensively explored. Limited studies suggest that dietary Mg intake and bone mineral density are correlated in adults, but no data from interventional studies in children and adolescents are available. OBJECTIVE: We sought to determine whether Mg supplementation in periadolescent girls enhances accrual of bone mass. DESIGN: We carried out a prospective, placebo-controlled, randomized, one-year double-blind trial of Mg supplementation. SETTING: The study was conducted in the Clinical Research Centers at Yale University School of Medicine. PATIENTS OR OTHER PARTICIPANTS: Healthy 8- to 14-yr-old Caucasian girls were recruited from community pediatricians' offices. Dietary diaries from over 120 volunteers were analyzed, and those with dietary Mg intake of less than 220 mg/d were invited to participate in the intervention. INTERVENTION: Magnesium (300 mg elemental Mg per day in two divided doses) or placebo was given orally for 12 months. MAIN OUTCOME MEASURE: The primary outcome measure was interval change in bone mineral content (BMC) of the total hip, femoral neck, Ward's area, and lumbar spine (L1-L4) after 12 months of Mg supplementation. RESULTS: Significantly increased accrual (P = 0.05) in integrated hip BMC occurred in the Mg-supplemented vs. placebo group. Trends for a positive Mg effect were evident in the pre- and early puberty and in mid-late puberty. Lumbar spinal BMC accrual was slightly (but not significantly) greater in the Mg-treated group. Compliance was excellent; 73% of capsules were ingested as inferred by pill counts. Serum mineral levels, calciotropic hormones, and bone markers were similar between groups. CONCLUSIONS: Oral Mg oxide capsules are safe and well tolerated. A positive effect of Mg supplementation on integrated hip BMC was evident in this small cohort.
Assuntos
Densidade Óssea/efeitos dos fármacos , Suplementos Nutricionais , Óxido de Magnésio/farmacologia , Administração Oral , Adolescente , Osso e Ossos/efeitos dos fármacos , Criança , Suplementos Nutricionais/efeitos adversos , Método Duplo-Cego , Feminino , Humanos , Óxido de Magnésio/administração & dosagem , Óxido de Magnésio/efeitos adversos , Cooperação do Paciente , PlacebosRESUMO
The incidence of nutritional rickets appears to be increasing in North American infants and toddlers; it is widely assumed that this is due to vitamin D deficiency. Thus, records of 43 children with nutritional rickets from greater New Haven, Connecticut, from 1986-2002 were identified. The mean age of presentation was 20 months; 86% were of African-American, Hispanic, or Middle Eastern descent. More than 93% of children had been breastfed; however, 15% had received vitamin D supplementation. Eighty-six percent of those with food histories available were weaned to diets with minimal dairy content after nursing. Serum 25-hydroxyvitamin D was 20.9 +/- 11.5 ng/ml and was less than 15 ng/ml in only 22% of patients. Three representative case histories suggest that dietary calcium intake may play a contributory role in the development of disease; 1 case documents radiographic and biochemical resolution of rachitic abnormalities after calcium treatment, but no vitamin D therapy. Clinicians should be aware that low dietary calcium intake after weaning may result in the development of nutritional rickets, and that attention to calcium intake as well as that of vitamin D is important in the establishment of optimal dietary practices for North American infants and children.
Assuntos
Cálcio da Dieta/uso terapêutico , Hidroxicolecalciferóis/sangue , Raquitismo/dietoterapia , Negro ou Afro-Americano , Cálcio/sangue , Cálcio/deficiência , Pré-Escolar , Connecticut/epidemiologia , Etnicidade , Feminino , Humanos , Lactente , Masculino , América do Norte/epidemiologia , Estudos Retrospectivos , Raquitismo/sangue , Raquitismo/epidemiologia , Deficiência de Vitamina D/complicaçõesRESUMO
Use of the Medtronic MiniMed Continuous Glucose Monitoring System (CGMS) in non-diabetic children has revealed many low and high sensor glucose (SG) values, suggesting that the original analytical algorithm (Solutions 2.0) might be overreading glycemic excursions. A revised algorithm (Solutions 3.0) was introduced in 2001. Our aim was to compare analyses of the same sensor profiles using both programs. Twenty-five lean, non-diabetic subjects (mean age 14 +/- 4 years) underwent continuous glucose monitoring with CGMS for up to 72 h. Sensor tracings were analyzed with both algorithms and compared. Separate analyses were performed for nocturnal readings (12-6 a.m.). Mean SG values were similar (103 +/- 24 mg/dL for version 2.0 vs. 100 +/- 14 for version 3.0), but the distribution was significantly different: 13.8% of total SG were <70 mg/dL by version 2.0 versus 8.2% by version 3.0 (p < 0.001), and 7.7% of total SG were >150 mg/dL by version 2.0 versus 4.7% by version 3.0 (p = 0.02). Of nocturnal SG values, 25.8% were <70 mg/dL by version 2.0 compared with 17.9% by version 3.0, and 9.4% were >150 mg/dL by version 2.0 compared with 4.0% by version 3.0. In lean non-diabetic children, Solutions 2.0 identified significantly more hypoglycemia and hyperglycemia than Solutions 3.0. Similar analyses in 40 children with type 1 diabetes revealed no significant differences. Solutions 3.0 may be a more useful algorithm for preventing over-reading of low and high SG readings in non-diabetic children, whereas both algorithms give similar results in children with diabetes.