RESUMEN
BACKGROUND AND PURPOSE: Early diagnosis of behavioral variant frontotemporal dementia (bvFTD) is challenging due to symptomatic overlap with primary psychiatric disorders (PPD). As emotion recognition deficits are early and key features of bvFTD, the aim was to explore processes driving social cognition deficits that may aid in the differentiation between bvFTD and PPD. METHODS: The total sample (N = 51) included 18 patients with bvFTD, 11 patients with PPD (mood, autism spectrum and psychotic disorders) and 22 controls from the Alzheimer Center Amsterdam of the Amsterdam UMC. Emotion recognition was assessed with the Ekman 60 Faces test, during which eye tracking metrics were collected in the first 5 s a face was presented. Group differences in dwell time on the total image as well as the circumscribed eyes area and mouth area were analysed using ANOVA, with post hoc comparisons. RESULTS: Patients with bvFTD scored lowest, patients with PPD scored intermediate and controls scored highest on emotion recognition. During facial processing, patients with bvFTD spent less dwell time on the total image than controls (mean difference 11.3%, F(2, 48) = 6.095, p = 0.004; bvFTD-controls p = 0.001, 95% confidence interval [CI] -892.64, -239.70). Dwell time on the eyes area did not differ between diagnostic groups, whilst patients with bvFTD spent less dwell time on the mouth area than PPD patients (mean difference 10.7%; F(2, 48) = 3.423, p = 0.041; bvFTD-PPD p = 0.022, 95% CI -986.38, -79.47) and controls (mean difference 7.8%; bvFTD-controls p = 0.043, 95% CI -765.91, -12.76). CONCLUSIONS: In bvFTD, decreased emotion recognition may be related to reduced focus on facial hallmarks. These findings suggest a valuable role for biometrics in social cognition assessment and the differentiation between bvFTD and PPD.
Asunto(s)
Enfermedad de Alzheimer , Demencia Frontotemporal , Humanos , Demencia Frontotemporal/psicología , Pruebas Neuropsicológicas , Reconocimiento en Psicología , Emociones , Cognición , Enfermedad de Alzheimer/diagnósticoRESUMEN
BACKGROUND: Data concerning the effects of afternoon snacking on ingestive behavior, mood, and cognition are limited. OBJECTIVE: The purpose of this study was to compare 1088 kJ of high-protein (HP) or high-fat (HF) afternoon snacks vs. no snacking on appetite, food intake, mood, and cognition in adolescents. METHODS: Thirty-one healthy adolescents (age: 17 ± 1 y) consumed the following afternoon snacks (in randomized order) for 3 d: HP snack (26 g of protein/6 g of fat per 27 g of carbohydrates), HF snack (4 g of protein/12 g of fat per 32 g of carbohydrates), and no snack (NoS). On day 4 of each treatment, the participants completed an 8-h testing day containing pre- and postsnack appetite questionnaires, food cue-stimulated functional MRI brain scans, mood, cognitive function, and eating initiation. Ad libitum dinner and evening snacks were provided and assessed. RESULTS: HP, but not HF, delayed eating initiation vs. NoS (P < 0.05). Both snacks reduced appetite vs. NoS (P < 0.001) with HP eliciting greater reductions than HF (P < 0.05). Only HF led to reductions in corticolimbic activation in brain regions controlling food motivation/reward vs. NoS (P < 0.01). Although no treatment differences in daily energy intake were detected, HP led to greater protein consumption than NoS (P < 0.05) and greater protein and lower fat consumption than HF (both, P < 0.05). HP led to fewer HF/high-sugar evening snacks than NoS (P < 0.01) and HF (P = 0.09). Although no treatment effects were detected for mood and cognition, HP tended to reduce confusion-bewilderment (P = 0.07) and increase cognitive flexibility (P = 0.09), whereas NoS reduced tension-anxiety (P < 0.05) and vigor-activity (P < 0.05). CONCLUSION: Afternoon snacking, particularly on HP soy foods, improves appetite, satiety, and diet quality in adolescents, while beneficially influencing aspects of mood and cognition. This trial was registered at clinicaltrials.gov as NCT01781286.
Asunto(s)
Afecto , Apetito , Cognición , Proteínas en la Dieta/administración & dosificación , Saciedad , Proteínas de Soja/administración & dosificación , Adolescente , Regulación del Apetito , Índice de Masa Corporal , Estudios Cruzados , Grasas de la Dieta/administración & dosificación , Sacarosa en la Dieta/administración & dosificación , Ingestión de Energía , Femenino , Voluntarios Sanos , Humanos , Imagen por Resonancia Magnética , Masculino , BocadillosRESUMEN
The 2014-2015 Ebola epidemic in West Africa has been the deadliest Ebola epidemic to date. In response to this deadly epidemic, the U.S. government declared this a top national security priority and members of the Commissioned Corps of the United States Public Health Service were tasked to provide direct patient care to Ebola virus disease patients. Commissioned Corps nurses provided the highest level of care under the most austere conditions. This article discusses the training, ethical dilemmas, and constant risk for potential exposure while working in an Ebola Treatment Unit.
Asunto(s)
Epidemias/prevención & control , Fiebre Hemorrágica Ebola/enfermería , United States Public Health Service/organización & administración , África Occidental/epidemiología , Fiebre Hemorrágica Ebola/epidemiología , Humanos , Capacitación en Servicio , Enfermería en Salud Pública/educación , Enfermería en Salud Pública/ética , Riesgo , Estados UnidosRESUMEN
In Canada and the United States, front-of-package protein content claims require data to support the quality of the protein. In general, protein quality reflects the product of the amino acid composition of the food protein relative to human amino acid requirements and a measure of digestibility. The currently accepted method in both jurisdictions is the protein digestibility-corrected amino acid score (PDCAAS) that requires the measurement of true fecal protein (nitrogen) digestibility. The latter must be measured in vivo using a rat model. This requirement for animal testing is inconsistent with international efforts to reduce the usage of animals in testing for regulatory purposes. The current commentary positions four options to remove the need to use animal testing for determining protein quality, when considering protein content claim substantiation. These options include (i) a focus on protein quantity alone; (ii) the use of the amino acid score alone, with no correction for digestibility; (iii) the use of a fixed digestibility coefficient to estimate protein quality; and (iv) the use of in vitro methods to measure protein and/or amino acid digestibility. The relative merits and deficiencies of the options are positioned with the goal of encouraging dialogue within the regulatory agencies to move towards alternative approaches for substantiating protein content claims on foods, including those derived from plant-based sources.
Asunto(s)
Proteínas en la Dieta , Digestión , Humanos , Ratas , Animales , Estados Unidos , Proteínas en la Dieta/análisis , Aminoácidos/análisis , Heces/química , CanadáRESUMEN
We performed a systematic review, meta-analysis, and meta-regression to determine if increasing daily protein ingestion contributes to gaining lean body mass (LBM), muscle strength, and physical/functional test performance in healthy subjects. A protocol for the present study was registered (PROSPERO, CRD42020159001), and a systematic search of Medline, Embase, CINAHL, and Web of Sciences databases was undertaken. Only randomized controlled trials (RCT) where participants increased their daily protein intake and were healthy and non-obese adults were included. Research questions focused on the main effects on the outcomes of interest and subgroup analysis, splitting the studies by participation in a resistance exercise (RE), age (<65 or ≥65 years old), and levels of daily protein ingestion. Three-level random-effects meta-analyses and meta-regressions were conducted on data from 74 RCT. Most of the selected studies tested the effects of additional protein ingestion during RE training. The evidence suggests that increasing daily protein ingestion may enhance gains in LBM in studies enrolling subjects in RE (SMD [standardized mean difference] = 0.22, 95% CI [95% confidence interval] 0.14:0.30, P < 0.01, 62 studies, moderate level of evidence). The effect on LBM was significant in subjects ≥65 years old ingesting 1.2-1.59 g of protein/kg/day and for younger subjects (<65 years old) ingesting ≥1.6 g of protein/kg/day submitted to RE. Lower-body strength gain was slightly higher by additional protein ingestion at ≥1.6 g of protein/kg/day during RE training (SMD = 0.40, 95% CI 0.09:0.35, P < 0.01, 19 studies, low level of evidence). Bench press strength is slightly increased by ingesting more protein in <65 years old subjects during RE training (SMD = 0.18, 95% CI 0.03:0.33, P = 0.01, 32 studies, low level of evidence). The effects of ingesting more protein are unclear when assessing handgrip strength and only marginal for performance in physical function tests. In conclusion, increasing daily protein ingestion results in small additional gains in LBM and lower body muscle strength gains in healthy adults enrolled in resistance exercise training. There is a slight effect on bench press strength and minimal effect performance in physical function tests. The effect on handgrip strength is unclear.
Asunto(s)
Entrenamiento de Fuerza , Adulto , Anciano , Ejercicio Físico , Terapia por Ejercicio , Humanos , Fuerza Muscular/fisiología , Músculos , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
For both children and adults with neurological, neurodevelopmental, medical, or psychiatric disorders, neuropsychological assessment can be a valuable tool in determining diagnosis, prognosis, and functional abilities as well as informing clinical management. This review summarizes the contributions of neuropsychological assessment to clinical care across diagnostic categories, with the goal of helping clinicians determine its utility for individual patients.
Asunto(s)
Discapacidades del Desarrollo/diagnóstico , Trastornos Mentales/diagnóstico , Enfermedades del Sistema Nervioso/diagnóstico , Pruebas Neuropsicológicas , HumanosRESUMEN
BACKGROUND: Several studies have shown a positive effect of fructo-oligosaccharides on calcium absorption and retention in animals and humans. Effects of levels of these pre-biotics that can be functionally incorporated into manufactured foods, have not been studied in controlled feeding studies. OBJECTIVES: This study was designed to evaluate the effect of 9 g/d of fructo-oligosaccharides as part of a controlled diet on calcium absorption and retention in adolescent girls. DESIGN: Fourteen healthy adolescent girls aged 11-13 y were studied in a metabolic setting for two 3-week periods separated by a 2-week washout period. In a randomized, double-blinded, crossover design, the teens received a diet containing either 9 g/d oligofructose-enriched inulin in a calcium-fortified cereal or the control cereal with no inulin. Both diets contained ~1500 mg calcium daily. Calcium retention was determined on the third week of each period. On day 14 of the diet period, fractional calcium absorption was determined from the enrichment of (44)Ca in 4-day urine collections. RESULTS: Calcium absorption (67 ± 3 vs. 66 ± 3%) and retention (409 ± 394 vs. 464 ± 241 mg/d) were not significantly different when diets contained 9 g/d oligofructose-enriched inulin or not in a calcium-fortified cereal. CONCLUSIONS: Daily consumption of cereal containing a combination of short- and long-chain fructo-oligosaccharides as part of a controlled diet did not benefit calcium absorption or retention in adolescent girls. Lack of response to the prebiotic in this cohort may relate to their already high calcium absorption efficiency.
Asunto(s)
Calcio de la Dieta/farmacocinética , Inulina/farmacología , Oligosacáridos/farmacología , Prebióticos , Adolescente , Isótopos de Calcio/farmacocinética , Calcio de la Dieta/metabolismo , Calcio de la Dieta/orina , Niño , Estudios Cruzados , Método Doble Ciego , Grano Comestible , Femenino , Alimentos Fortificados , Humanos , Absorción IntestinalRESUMEN
Patients with lupus membranous nephropathy (LMN) are at substantial long-term risk for morbidity and mortality associated with protracted nephrotic syndrome, including ESRD. The optimal treatment for this condition is controversial. Forty-two patients with LMN participated in a randomized, controlled trial to compare adjunctive immunosuppressive drugs with prednisone alone. Adjunctive regimens included either cyclosporine (CsA) for 11 mo or alternate-month intravenous pulse cyclophosphamide (IVCY) for six doses; the control group received alternate-day prednisone alone. Median proteinuria was 5.4 g/d (range 2.7 to 15.4 g/d). We assessed the primary outcome, time to remission of proteinuria during the 12-mo protocol, by univariate survival analysis. At 1 yr, the cumulative probability of remission was 27% with prednisone, 60% with IVCY, and 83% with CsA. Although both IVCY and CsA were more effective than prednisone in inducing remissions of proteinuria, relapse of nephrotic syndrome occurred significantly more often after completion of CsA than after IVCY. By multivariate survival analysis, treatment with prednisone and high-grade proteinuria (>5 g/d) but not race or ethnicity were independently associated with a decreased probability of remission. Adverse effects during the 12-mo protocol included insulin-requiring diabetes (one with prednisone and two with CsA), pneumonia (one with prednisone and two with CsA), and localized herpes zoster (two with IVCY). In conclusion, regimens containing CsA or IVCY are each more effective than prednisone alone in inducing remission of proteinuria among patients with LMN.
Asunto(s)
Ciclofosfamida/uso terapéutico , Ciclosporina/uso terapéutico , Inmunosupresores/uso terapéutico , Nefritis Lúpica/tratamiento farmacológico , Prednisona/uso terapéutico , Adolescente , Adulto , Edad de Inicio , Femenino , Hematócrito , Humanos , Nefritis Lúpica/inmunología , Masculino , Persona de Mediana Edad , Pronóstico , Proteinuria/tratamiento farmacológico , Albúmina Sérica/efectos de los fármacos , Albúmina Sérica/metabolismo , Adulto JovenRESUMEN
Capacity assessment is a growing area of practice in geriatrics. In this pilot study we illustrate the potential relationship between clinician variables and capacity ratings. Twelve older adults with mild dementia or schizophrenia were rated by six clinicians from diverse disciplinary backgrounds. Capacity ratings were associated with clinician values regarding patient involvement in medical decisions, clinician-patient mismatches on such values, and emotional reactions to patients. Expanding our understanding of the impact of clinician variables on capacity ratings may enhance the reliability and validity of capacity assessments and help to promote autonomy when appropriate.
RESUMEN
BACKGROUND: There are limited data in adolescents on racial differences in relationships between dietary calcium intake, absorption, and retention and serum levels of calcium-regulating hormones. OBJECTIVES: The aim of this study was to investigate these relationships cross-sectionally in American White and Black adolescent girls. METHODS: Calcium balance studies were conducted in 105 girls, aged 11-15 yr, on daily calcium intakes ranging from 760-2195 mg for 3-wk controlled feeding periods; 158 observations from 52 Black and 53 White girls were analyzed. RESULTS: Black girls had lower serum 25-hydroxyvitamin D [25(OH)D], higher serum 1,25-dihydroxyvitamin D, and higher calcium absorption and retention than White girls. Calcium intake and race, but not serum 25(OH)D, predicted net calcium absorption and retention with Black girls absorbing calcium more efficiently at low calcium intakes than White girls. The relationship between serum 25(OH)D and serum PTH was negative only in White girls. Calcium intake, race, and postmenarcheal age explained 21% of the variation in calcium retention, and serum 25(OH)D did not contribute further to the variance. CONCLUSIONS: These results suggest that serum 25(OH)D does not contribute to the racial differences in calcium absorption and retention during puberty.
Asunto(s)
Población Negra , Calcio de la Dieta/administración & dosificación , Calcio de la Dieta/metabolismo , Suplementos Dietéticos , Vitamina D/sangre , Población Blanca , Adolescente , Fenómenos Fisiológicos Nutricionales de los Adolescentes/etnología , Población Negra/estadística & datos numéricos , Niño , Estudios Transversales , Relación Dosis-Respuesta a Droga , Ingestión de Alimentos/fisiología , Femenino , Estudios de Seguimiento , Humanos , Estado Nutricional/fisiología , Pubertad/metabolismo , Pubertad/fisiología , Vitamina D/metabolismo , Población Blanca/estadística & datos numéricosRESUMEN
CONTEXT: The relationship between calcium (Ca) intake and Ca retention in adolescent boys was recently reported. OBJECTIVE: This study evaluated the influence of Ca intake, serum hormone levels, biomarkers of bone metabolism, habitual physical activity, habitual Ca intake, and physical fitness on Ca retention in the same sample. DESIGN: This study was a randomized, cross-over design that consisted of two 3-wk metabolic balance periods. SETTING: The study took place on a university campus as a summer camp. PATIENTS OR OTHER PARTICIPANTS: A total of 31 American white boys (13-15 yr) participated in the study. INTERVENTIONS: Each subject consumed a controlled diet with one of five high-low Ca intake pairs that ranged from 670-2003 mg/d, which was manipulated utilizing a fortified beverage. MAIN OUTCOME MEASURES: Ca retention was determined by Ca intake minus urinary and fecal Ca excretion during each balance period. RESULTS: Ca intake explained 21.7% of the variability in Ca retention, and serum IGF-I concentration explained an additional 11.5%. Other serum hormone levels did not significantly add to the model. Biomarkers of bone metabolism, habitual physical activity, habitual Ca intake, and physical fitness were not significant predictors of Ca retention in adolescent boys. CONCLUSIONS: IGF-I, a regulator of growth during puberty, is an important predictor of Ca retention in adolescent boys. However, dietary Ca intake is an even greater predictor of Ca retention during this period of growth.
Asunto(s)
Calcio de la Dieta/metabolismo , Calcio/metabolismo , Adolescente , Antropometría , Bebidas , Biomarcadores , Huesos/metabolismo , Calcio/orina , Dieta , Método Doble Ciego , Heces/química , Conducta Alimentaria , Hábitos , Hormonas/sangre , Humanos , Factor I del Crecimiento Similar a la Insulina/metabolismo , Estilo de Vida , Masculino , Actividad Motora/fisiología , Aptitud Física , Valor Predictivo de las PruebasRESUMEN
In December 2017, the National Academy of Neuropsychology convened an interorganizational Summit on Population Health Solutions for Assessing Cognitive Impairment in Geriatric Patients in Denver, Colorado. The Summit brought together representatives of a broad range of stakeholders invested in the care of older adults to focus on the topic of cognitive health and aging. Summit participants speciï¬cally examined questions of who should be screened for cognitive impairment and how they should be screened in medical settings. This is important in the context of an acute illness given that the presence of cognitive impairment can have signiï¬cant implications for care and for the management of concomitant diseases as well as pose a major risk factor for dementia. Participants arrived at general principles to guide future screening approaches in medical populations and identiï¬ed knowledge gaps to direct future research. Key learning points of the summit included: recognizing the importance of educating patients and healthcare providers about the value of assessing current and baseline cognition;emphasizing that any screening tool must be appropriately normalized and validated in the population in which it is used to obtain accurate information, including considerations of language, cultural factors, and education; andrecognizing the great potential, with appropriate caveats, of electronic health records to augment cognitive screening and tracking of changes in cognitive health over time.
RESUMEN
In December 2017, the National Academy of Neuropsychology convened an interorganizational Summit on Population Health Solutions for Assessing Cognitive Impairment in Geriatric Patients in Denver, Colorado. The Summit brought together representatives of a broad range of stakeholders invested in the care of older adults to focus on the topic of cognitive health and aging. Summit participants specifically examined questions of who should be screened for cognitive impairment and how they should be screened in medical settings. This is important in the context of an acute illness given that the presence of cognitive impairment can have significant implications for care and for the management of concomitant diseases as well as pose a major risk factor for dementia. Participants arrived at general principles to guide future screening approaches in medical populations and identified knowledge gaps to direct future research. Key learning points of the summit included: recognizing the importance of educating patients and healthcare providers about the value of assessing current and baseline cognition; emphasizing that any screening tool must be appropriately normalized and validated in the population in which it is used to obtain accurate information, including considerations of language, cultural factors, and education; and recognizing the great potential, with appropriate caveats, of electronic health records to augment cognitive screening and tracking of changes in cognitive health over time.
Asunto(s)
Disfunción Cognitiva/diagnóstico , Disfunción Cognitiva/psicología , Pruebas Neuropsicológicas , Salud Poblacional , Anciano , Anciano de 80 o más Años , Disfunción Cognitiva/epidemiología , Colorado , Congresos como Asunto/tendencias , Atención a la Salud/métodos , Demencia/diagnóstico , Demencia/epidemiología , Demencia/psicología , Femenino , Humanos , MasculinoRESUMEN
BACKGROUND: Higher bone mass in blacks than in whites has been related to greater calcium utilization efficiency. Dietary calcium requirements for maximal skeletal calcium accretion during puberty may differ between the races. OBJECTIVE: This study compared the relation between calcium intake and calcium retention in black and white adolescent girls. DESIGN: A range of controlled calcium intakes (760-1981 mg Ca/d) were used in 3-wk controlled balance studies. Some subjects were studied more than once; a total of 182 observations from 55 black girls and 66 white girls were analyzed. RESULTS: Blacks had 185 +/- 32 mg/d greater mean skeletal calcium retention than did whites (P < 0.0001) at all calcium intakes as a result of significantly greater net calcium absorption (P < 0.001) and lower calcium excretion (P < 0.0001). CONCLUSIONS: Dietary calcium requirements did not differ with race. Higher calcium retention at all calcium intakes during adolescence may underlie the higher bone mineral content of adult blacks than of adult whites.
Asunto(s)
Población Negra , Densidad Ósea , Huesos/metabolismo , Calcio/metabolismo , Población Blanca , Absorción , Adolescente , Biomarcadores/sangre , Huesos/química , Calcio/administración & dosificación , Calcio/análisis , Calcio de la Dieta/administración & dosificación , Suplementos Dietéticos , Femenino , HumanosRESUMEN
A meta-analysis of 26 studies was conducted to assess whether more complex forms of psychotherapy would be superior to control treatments of either biofeedback, progressive muscle relaxation, or both. Consistent with hypotheses, more complex treatments provided a small, significant improvement over biofeedback and progressive muscle relaxation (r = .09). A subset of the more complex behavioral treatments accounted for most of this small incremental effectiveness of more complex treatments (r = .15). Possible sources of this incremental effectiveness are discussed.
Asunto(s)
Biorretroalimentación Psicológica , Relajación Muscular , Psicoterapia/métodos , Terapia por Relajación , HumanosRESUMEN
BACKGROUND: National calcium requirements in the United States for boys are based on data from girls. On average, boys develop larger skeletons than do girls, yet it is unknown whether the additional skeletal accretion in boys requires additional dietary calcium intake. OBJECTIVE: The objective was to determine calcium retention in adolescent boys in response to a range of controlled intakes and to compare the intake needed for maximal retention in boys with that needed in adolescent girls studied under the same conditions. DESIGN: Thirty-one boys aged 12-15 y participated in 3-wk metabolic balance studies testing a range (700-2100 mg/d) of calcium intakes in a crossover study design with a 2-wk washout period. Calcium intake was varied by using a beverage fortified with calcium citrate malate. After a 1-wk equilibration period, calcium retention was calculated as dietary calcium intake minus the calcium excreted in the feces and urine over the following 2 wk. The dietary intake at which maximal calcium retention occurred was determined by using a nonlinear regression model. The results in boys were compared with those obtained in 35 adolescent girls previously studied under the same protocol. RESULTS: Maximal calcium retention in boys was achieved at an intake of 1140 mg/d. Calcium retention was higher (by 171 +/- 38 mg/d) in boys than in girls at all calcium intakes studied. CONCLUSION: The higher calcium retention in boys than in girls was attained through higher net calcium absorption and lower urinary excretion than in girls.
Asunto(s)
Fenómenos Fisiológicos Nutricionales de los Adolescentes , Huesos/metabolismo , Calcio de la Dieta/administración & dosificación , Calcio de la Dieta/farmacocinética , Adolescente , Huesos/efectos de los fármacos , Calcio de la Dieta/metabolismo , Calcio de la Dieta/orina , Estudios Cruzados , Relación Dosis-Respuesta a Droga , Heces/química , Femenino , Alimentos Fortificados , Humanos , Absorción Intestinal , Masculino , Necesidades Nutricionales , Caracteres Sexuales , UrinálisisRESUMEN
INTRODUCTION: There is broad consensus that high grade basal proteinuria and failure to achieve remission of proteinuria are key determinants of adverse renal prognosis in patients with primary membranous nephropathy. Based on the fact that current regimens are not ideal due to short and long-term toxicity and propensity to relapse after treatment withdrawal, we developed a treatment protocol based on a novel combination of rituximab and cyclosporine which targets both the B and T cell limbs of the immune system. Herein, we report pilot study data on proteinuria, changes in autoantibody levels and renal function that offer a potentially effective new approach to treatment of severe membranous nephropathy. METHODS: Thirteen high-risk patients defined by sustained high-grade proteinuria (mean 10.8 g/d) received combination induction therapy with rituximab plus cyclosporine for 6 months, followed by a second cycle of rituximab and tapering of cyclosporine during an 18 month maintenance phase. RESULTS: Mean proteinuria decreased by 65% at 3 months and by 80% at 6 months. Combined complete or partial remission was achieved in 92% of patients by 9 months; 54% achieved complete remission at 12 months. Two patients relapsed during the trial. All patients with autoantibodies to PLA2R achieved antibody depletion. Renal function stabilized. The regimen was well tolerated. DISCUSSION: We report these encouraging preliminary results for their potential value to other investigators needing prospectively collected data to inform the design and power calculations of future randomized clinical trials. Such trials will be needed to formally compare this novel regimen to current therapies for membranous nephropathy.
RESUMEN
BACKGROUND: Previously, we showed that black girls retained more calcium than white girls did and that salt loading negatively affected calcium retention. Racial differences likely exist in other bone minerals also, such as magnesium, in response to salt loading during growth. OBJECTIVE: We studied racial differences in magnesium metabolism in response to dietary sodium and calcium during rapid bone growth. DESIGN: Twenty-seven white and 40 black girls (11-15 y old) were studied for 3 wk while they consumed low-sodium (1.3 g/d) and high-sodium (3.8 g/d) diets by using a randomized-order, crossover metabolic study with 3 dietary calcium intakes; the magnesium dietary intake was fixed at 230 mg/d. Urine and feces were collected during each 3-wk period in 24-h pools and analyzed for magnesium. A mixed-model ANOVA was used to determine the effect of race and dietary sodium with calcium intake as a covariate. RESULTS: Salt loading or calcium intake had no significant effect on urinary magnesium excretion. Blacks excreted significantly less urinary magnesium (mean ± SD: 83.8 ± 25.6 mg/d) than did whites (94.9 ± 27.3 mg/d; P < 0.05). No effects were observed in fecal magnesium excretion. Magnesium retention was higher with the low-sodium diet (50.1 ± 44.0 mg/d) than with the high-sodium diet (39.3 ± 49.8 mg/d) (P < 0.05), with no effects of race or calcium intake. Salt loading had no effect on biomarkers. Whites had higher 25-hydroxyvitamin D and insulin-like growth factor binding protein 3 but lower 1,25-dihydroxyvitamin D and parathyroid hormone concentrations. CONCLUSIONS: Blacks excreted less urinary magnesium than did whites. Magnesium retention was similar between races but higher with the low-sodium diet. Kinetic studies are needed to fully explain magnesium homeostasis. This trial was registered at clinicaltrials.gov as NCT01564238.
Asunto(s)
Población Negra , Calcio de la Dieta/administración & dosificación , Magnesio/orina , Cloruro de Sodio Dietético/administración & dosificación , Población Blanca , Adolescente , Biomarcadores , Índice de Masa Corporal , Peso Corporal , Niño , Estudios Cruzados , Dieta , Heces/química , Femenino , Homeostasis/efectos de los fármacos , Humanos , Magnesio/administración & dosificación , Magnesio/sangre , Actividad Motora , Encuestas y CuestionariosRESUMEN
CONTEXT: Overweight adolescents have low bone mineral content for weight and are at increased risk for fractures. OBJECTIVE: The aim was to determine whether overweight and obesity influence the positive relationship between dietary calcium intake and skeletal calcium retention in adolescents. DESIGN: Analysis of pooled data from calcium balance studies in adolescents. SETTING: Participants each underwent a 3-wk calcium balance study in a controlled environment. PARTICIPANTS: Participants included 280 White, Black, and Asian boys (n = 73) and girls (n = 207) ages 10-16 yr. MAIN OUTCOME MEASURE: The relationship among body mass index (BMI), calcium intake, and calcium retention was modeled using linear regression. RESULTS: Calcium intake, BMI, sex, race, and age explained 27.9% of the variation in calcium retention. At low calcium intakes, there was no effect of BMI on skeletal calcium retention, but at higher calcium intakes, BMI increased skeletal calcium retention. CONCLUSIONS: Greater gains in calcium retention occur with increases in calcium intake in adolescents with higher BMI compared with those with lower BMI. Additional studies are needed to investigate whether increasing calcium intake reduces the increased risk of fracture associated with overweight and obesity in adolescents.