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1.
Public Health Nutr ; 18(3): 474-81, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24780506

RESUMEN

OBJECTIVE: The relationship of meal and snacking patterns with overall dietary intake and relative weight in children is unclear. The current study was done to examine how eating, snack and meal frequencies relate to total energy intake and diet quality. DESIGN: The cross-sectional associations of eating, meal and snack frequencies with total energy intake and diet quality, measured by the Healthy Eating Index 2005 (HEI-2005), were examined in separate multivariable mixed models. Differences were examined between elementary school-age participants (9-11 years) and adolescents (12-15 years). SETTING: Two non-consecutive 24 h diet recalls were collected from children attending four schools in the greater Boston area, MA, USA. SUBJECTS: One hundred and seventy-six schoolchildren, aged 9-15 years. RESULTS: Overall, 82% of participants consumed three daily meals. Eating, meal and snack frequencies were statistically significantly and positively associated with total energy intake. Each additional reported meal and snack was associated with an 18·5% and a 9·4% increase in total energy intake, respectively (P<0·001). The relationships of eating, meal and snack frequencies with diet quality differed by age category. In elementary school-age participants, total eating occasions and snacks increased HEI-2005 score. In adolescents, each additional meal increased HEI-2005 score by 5·40 points (P=0·01), whereas each additional snack decreased HEI-2005 score by 2·73 points (P=0·006). CONCLUSIONS: Findings suggest that snacking increases energy intake in schoolchildren. Snacking is associated with better diet quality in elementary school-age children and lower diet quality in adolescents. Further research is needed to elucidate the role of snacking in excess weight gain in children and adolescents.


Asunto(s)
Envejecimiento , Fenómenos Fisiológicos Nutricionales Infantiles , Dieta/efectos adversos , Ingestión de Energía , Conducta Alimentaria , Política Nutricional , Cooperación del Paciente , Adolescente , Conducta del Adolescente , Fenómenos Fisiológicos Nutricionales de los Adolescentes , Boston , Niño , Conducta Infantil , Estudios de Cohortes , Estudios Transversales , Dieta/economía , Femenino , Humanos , Masculino , Comidas , Pobreza , Instituciones Académicas , Bocadillos
2.
J Nutr ; 142(5): 936-41, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22437558

RESUMEN

Inadequate vitamin K intake has been associated with abnormal soft tissue calcification. Older adults may have insufficient intakes of vitamin K and respond less to vitamin K supplementation compared with younger adults. However, little is known about the determinants that influence the response to vitamin K supplementation. Our primary objective was to assess dietary and nondietary determinants of vitamin K status in healthy younger and older adults. In a nonrandomized, nonmasked study, 21 younger (18-40 y) and 21 older (55-80 y) men and women consumed a baseline diet (200 µg phylloquinone/d) for 5 d, a phylloquinone-restricted diet (10 µg phylloquinone/d) for 28 d, and a phylloquinone-supplemented diet (500 µg phylloquinone/d) for 28 d. Changes in vitamin K status markers in response to vitamin K depletion and repletion were studied and the influences of BMI, body fat, and circulating TG were assessed by including them as covariates in the model. Despite baseline differences in measures of vitamin K status, plasma phylloquinone tended to increase (P = 0.07) and the percentage of uncarboxylated osteocalcin and uncarboxylated prothrombin both improved with phylloquinone supplementation (P < 0.007), regardless of age group or sex. Only the excretion of urinary menadione, a vitamin K metabolite, was greater among younger adults in response to depletion than in older adults (P = 0.012), regardless of sex. Adiposity measures and circulating TG did not predict response of any measures. In conclusion, poor vitamin K status can be similarly improved with vitamin K supplementation, regardless of age group or sex.


Asunto(s)
Deficiencia de Vitamina D/sangre , Deficiencia de Vitamina D/tratamiento farmacológico , Vitamina K 1/administración & dosificación , Vitamina K 1/sangre , Vitaminas/administración & dosificación , Vitaminas/sangre , Adiposidad , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Biomarcadores/sangre , Suplementos Dietéticos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Osteocalcina/sangre , Factores Sexuales , Triglicéridos/sangre , Vitamina K 3/orina , Adulto Joven
3.
J Clin Periodontol ; 39(1): 62-72, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22093005

RESUMEN

AIM: A double-blind randomized controlled trial to determine whether dietary supplementation with fruit/vegetable/berry juice powder concentrates, simultaneously with non-surgical periodontal therapy, improved 2-month treatment outcomes. METHODS: Volunteers with chronic periodontitis were randomly assigned to one of three groups: fruit/vegetable (FV), fruit/vegetable/berry (FVB) or placebo. Supplements were taken daily during non-surgical debridement and maintenance and outcomes assessed at 2, 5 and 8 months after completion. Primary outcomes were mean probing pocket depth (PPD), clinical attachment gain, % sites bleeding on probing (% BOP) at 2 months. Adherence and plasma ß-carotene were determined. RESULTS: Sixty-one nutritionally replete (by serum biochemistry) volunteers enrolled and 60 (n = 20 per arm) completed the 2-month review. Clinical outcomes improved in all groups at 2 months, with additional improvement in PPD versus placebo for FV (p < 0.03). Gingival crevicular fluid volumes diminished more in supplement groups than placebo (FVB; p < 0.05) at 2 months, but not at later times. The % BOP (5 months) and cumulative plaque scores (8 months) were lowered more in the FV group (p < 0.05). CONCLUSIONS: Adjunctive juice powder concentrates appear to improve initial pocket depth reductions in nutritionally replete patients, where plasma micronutrient bioavailability is attainable. Definitive multicentre studies in untreated and treated patients are required to ascertain the clinical significance of such changes.


Asunto(s)
Antioxidantes/administración & dosificación , Profilaxis Dental , Suplementos Dietéticos , Micronutrientes/administración & dosificación , Periodontitis/terapia , Preparaciones de Plantas/administración & dosificación , Adulto , Anciano , Método Doble Ciego , Femenino , Frutas , Humanos , Masculino , Persona de Mediana Edad , Fitoterapia/métodos , Plantas Comestibles , Resultado del Tratamiento , Verduras
4.
J Ren Nutr ; 22(2): 268-276.e3, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22153382

RESUMEN

OBJECTIVE: Hyperhomocysteinemia and B-vitamin deficiency may be treatable risk factors for cognitive impairment and decline. Hyperhomocysteinemia, cognitive impairment, and depression are all common in individuals with kidney disease, including kidney transplant recipients. Accordingly, we assessed the prevalence of cognitive impairment and depressive symptoms in transplant recipients and their association with kidney function, plasma total homocysteine, and B-vitamin concentrations. SETTING: Cross-sectional analysis of baseline data from the Folic Acid for Vascular Outcome Reduction In Transplantation (FAVORIT) Ancillary Cognitive Trial (FACT), which included 183 participants in FAVORIT who underwent detailed neuropsychological assessment before the study intervention. RESULTS: The mean age was 54.0 ± 9.5 years (range: 7 to 386 months). Men comprised 55.2% of the cohort, and the mean time between the current transplant and cognitive testing was 7.0 ± 5.8 years. Twenty-four percent of participants reported neurological or psychiatric complaints, and 30% exhibited symptoms of mild to severe depression. Testing revealed evidence of significant and selective deficits in this population: 33% performed more than 1 standard deviation (SD) below normed means on a memory test, 58% fell lower than 1 SD below the norms on a test of attention and mental processing speed, and 33% to 42% fell lower than 1 SD below the norms on several tests of executive function. Lower estimated glomerular filtration rate and lower folate were associated with poorer performance on tests of memory and executive function. CONCLUSIONS: These observations confirm previous reports of mood and cognitive impairments in adult kidney transplant recipients. Further research is needed to determine the benefit of B-vitamin supplementation and other interventions in this patient population.


Asunto(s)
Trastornos del Conocimiento/fisiopatología , Depresión/fisiopatología , Suplementos Dietéticos , Trasplante de Riñón , Trastornos del Conocimiento/etiología , Estudios Transversales , Depresión/etiología , Femenino , Tasa de Filtración Glomerular , Homocisteína/sangre , Humanos , Hiperhomocisteinemia/fisiopatología , Riñón/fisiopatología , Enfermedades Renales/complicaciones , Enfermedades Renales/fisiopatología , Modelos Logísticos , Masculino , Persona de Mediana Edad , Estudios Multicéntricos como Asunto , Ensayos Clínicos Controlados Aleatorios como Asunto , Deficiencia de Vitamina B/fisiopatología , Vitaminas/administración & dosificación , Vitaminas/sangre
5.
J Am Acad Dermatol ; 64(1): 107-12, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21167405

RESUMEN

BACKGROUND: Immunohistochemistry (IHC) applied to Mohs micrographic surgery (MMS) is time consuming and labor intensive, and the variability of staining quality has prevented its widespread use in clinical practice. OBJECTIVE: To investigate the readability of immunostains processed by a novel automated 16-minute technique used for evaluation of frozen sections prepared during MMS for melanoma. METHODS: A rapid automated instrument that performs MART-1 (melanoma antigen recognized by T cells) immunostains in 16 minutes was used to stain frozen sections and was compared with MART-1 stains of paraffin (permanent) sections, hematoxylin-eosin (H&E) stains of frozen and permanent sections from the positive or negative control specimens of the Mohs layers for melanoma. A total of 480 interpretations from 48 sections (4 types of stains for each specimen, 12 specimens read by 10 interpreters) were analyzed via blinded examination by 5 dermatopathologists and 5 Mohs surgeons at two institutions. A scoring system was used to assess the readability of each slide. Analysis of variance was used for statistical analysis. RESULTS: In terms of clarity of interpreting melanoma sections, the 16-minute MART-1 IHC of frozen sections is equivalent to the standard MART-1 of permanent sections. The 16-minute MART-1 sections are also significantly easier to interpret than permanent sections stained with H&E for both the dermatopathologists and Mohs surgeons (P < .05). LIMITATIONS: The study represents data collected from only two institutions in the United States. CONCLUSION: The rapid-stained frozen IHC sections are significantly easier to interpret than the "gold standard" permanent sections stained with H&E. This technology facilitates the rapid interpretation of melanoma in frozen sections.


Asunto(s)
Antígenos Específicos del Melanoma/análisis , Melanoma/cirugía , Cirugía de Mohs/métodos , Neoplasias Cutáneas/cirugía , Coloración y Etiquetado/métodos , Automatización , Biopsia con Aguja , Eosina Amarillenta-(YS) , Estudios de Evaluación como Asunto , Femenino , Secciones por Congelación/métodos , Hematoxilina , Humanos , Inmunohistoquímica , Cuidados Intraoperatorios/métodos , Masculino , Melanoma/patología , Muestreo , Sensibilidad y Especificidad , Neoplasias Cutáneas/patología , Factores de Tiempo , Estados Unidos
6.
Public Health Nutr ; 14(5): 758-67, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-20955641

RESUMEN

OBJECTIVE: The proportion of the Latin American population aged >60 years is expected to double during the next few decades. Metabolic syndrome (MetS) is associated with high morbidity and mortality worldwide. However, little is known about MetS in Latin America in general, and in Ecuador in particular. The present study aimed to examine the prevalence of MetS and its association with blood micronutrient, homocysteine (Hcy) and C-reactive protein (CRP) concentrations in the elderly living in a low-income urban area. DESIGN: We performed a cross-sectional study. MetS, using the International Diabetes Federation definition, dietary intake and plasma micronutrient, CRP and Hcy concentrations were assessed. SUBJECTS: A total of 352 elderly (≥65 years) Ecuadorians. SETTING: Quito, Ecuador. RESULTS: MetS was prevalent (40%)--considerably more so among women (81%) than men (19%; χ² = 32·6, P < 0·0001). Further, 53 % of those without MetS exhibited two or more of its components. Micronutrient deficiencies were prevalent, including those of vitamin C, zinc, vitamin B12 and folate. Vitamin C and E concentrations were inversely (OR = 0·78, 95% CI 0·71, 0·86; OR = 0·16, 95% CI 0·03, 0·81, respectively) and CRP (OR = 1·79, 95 % CI 1·04, 3·06) was positively associated with MetS. CONCLUSIONS: The coexistence of MetS with micronutrient deficiencies suggests that elderly Ecuadorians suffer from the double burden of diseases that are increasingly being observed in less developed countries. More research is needed to determine the causal factors, but results presented suggest that these older adults would benefit from interventions to reduce the risk factors for MetS, in particular higher consumption of micronutrient-rich foods.


Asunto(s)
Proteína C-Reactiva/metabolismo , Homocisteína/sangre , Síndrome Metabólico/sangre , Síndrome Metabólico/epidemiología , Micronutrientes/sangre , Anciano , Estudios Transversales , Ecuador/epidemiología , Femenino , Humanos , Masculino , Micronutrientes/deficiencia , Factores Sexuales
7.
JAMA ; 306(3): 287-93, 2011 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-21771989

RESUMEN

CONTEXT: National recommendations for the prevention and treatment of obesity emphasize reducing energy intake. Foods purchased in restaurants provide approximately 35% of the daily energy intake in US individuals but the accuracy of the energy contents listed for these foods is unknown. OBJECTIVE: To examine the accuracy of stated energy contents of foods purchased in restaurants. DESIGN AND SETTING: A validated bomb calorimetry technique was used to measure dietary energy in food from 42 restaurants, comprising 269 total food items and 242 unique foods. The restaurants and foods were randomly selected from quick-serve and sit-down restaurants in Massachusetts, Arkansas, and Indiana between January and June 2010. MAIN OUTCOME MEASURE: The difference between restaurant-stated and laboratory-measured energy contents, which were corrected for standard metabolizable energy conversion factors. RESULTS: The absolute stated energy contents were not significantly different from the absolute measured energy contents overall (difference of 10 kcal/portion; 95% confidence interval [CI], -15 to 34 kcal/portion; P = .52); however, the stated energy contents of individual foods were variable relative to the measured energy contents. Of the 269 food items, 50 (19%) contained measured energy contents of at least 100 kcal/portion more than the stated energy contents. Of the 10% of foods with the highest excess energy in the initial sampling, 13 of 17 were available for a second sampling. In the first analysis, these foods contained average measured energy contents of 289 kcal/portion (95% CI, 186 to 392 kcal/portion) more than the stated energy contents; in the second analysis, these foods contained average measured energy contents of 258 kcal/portion (95% CI, 154 to 361 kcal/portion) more than the stated energy contents (P <.001 for each vs 0 kcal/portion difference). In addition, foods with lower stated energy contents contained higher measured energy contents than stated, while foods with higher stated energy contents contained lower measured energy contents (P <.001). CONCLUSIONS: Stated energy contents of restaurant foods were accurate overall. However, there was substantial inaccuracy for some individual foods, with understated energy contents for those with lower energy contents.


Asunto(s)
Ingestión de Energía , Análisis de los Alimentos , Etiquetado de Alimentos , Alimentos/estadística & datos numéricos , Legislación Alimentaria , Restaurantes/estadística & datos numéricos , Arkansas , Calorimetría , Dieta , Revelación , Humanos , Indiana , Massachusetts , Obesidad/prevención & control , Control de Calidad , Reproducibilidad de los Resultados
8.
J Lipid Res ; 51(8): 2405-12, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20631298

RESUMEN

Plasma lipoproteins and glucose homeostasis were evaluated after marked weight loss before and over 12 months following Roux-en-Y gastric-bypass (RYGBP) surgery in 19 morbidly obese women. Standard lipids, remnant-lipoprotein cholesterol (RLP-C); HDL-triglyceride (TG); apolipoproteins (apo) A-I, A-II, E, and A-I-containing HDL subpopulations; lecithin-cholesterol acyltransferase (LCAT) and cholesteryl ester transfer protein (CETP) mass and activity; plasma glucose and insulin levels were measured before and at 1, 3, 6, and 12 months after GBP surgery. Baseline concentrations of TG, RLP-C, glucose, and insulin were significantly higher in obese than in normal-weight, age-matched women, whereas HDL cholesterol (HDL-C), apoA-I, apoA-II, alpha-1 and alpha-2 levels were significantly lower. Over 1 year, significant decreases of body mass index, glucose, insulin, TG, RLP-C, HDL-TG, and prebeta-1 levels were observed with significant increases of HDL-C and alpha-1 levels (all P < 0.05). Changes of fat mass were correlated with those of LDL cholesterol (P = 0.018) and LCAT mass (P = 0.011), but not with CETP mass (P = 0.265). Changes of fasting plasma glucose concentrations were inversely correlated with those of CETP mass (P = 0.005) and alpha-1 level (P = 0.004). Changes of fasting plasma insulin concentrations were positively correlated with those of LCAT mass (P = 0.043) and inversely with changes of alpha-1 (P = 0.03) and alpha-2 (P = 0.05) concentrations. These results demonstrate beneficial changes in HDL remodeling following substantial weight loss induced by RYGBP surgery and that these changes are associated with improvement of glucose homeostasis in these patients.


Asunto(s)
Derivación Gástrica , Lipoproteínas HDL/metabolismo , Obesidad Mórbida/metabolismo , Obesidad Mórbida/cirugía , Pérdida de Peso , Tejido Adiposo/metabolismo , Adulto , Biomarcadores/metabolismo , Enfermedades Cardiovasculares/metabolismo , Estudios de Casos y Controles , Proteínas de Transferencia de Ésteres de Colesterol/metabolismo , Femenino , Humanos , Obesidad Mórbida/patología , Obesidad Mórbida/fisiopatología , Fosfatidilcolina-Esterol O-Aciltransferasa/metabolismo , Riesgo
9.
Clin Endocrinol (Oxf) ; 72(1): 22-5, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19320650

RESUMEN

OBJECTIVE: Calcium absorption is an important determinant of calcium retention and bone metabolism. However, most methods of measuring calcium absorption, including the well-established dual stable isotope method, are costly and cumbersome to implement. We evaluated whether an oral calcium tolerance test (OCTT), which involves measuring calcium excretion in a fasting 2-h urine collection and two 2-h collections following an oral calcium dose, may be a useful index of calcium absorption in older adults consuming a fixed calcium intake of 30 mmol/day. DESIGN: After a 10-day metabolic diet containing 30 mmol/day of calcium, subjects had calcium absorption measured using the dual stable isotope method and the OCTT. PARTICIPANTS: Eleven healthy subjects aged 54-74 years. MEASUREMENTS: Fractional calcium absorption (FCA), calcium excretion in a fasting 2-h urine collection and two 2-h collections in response to a 10-mmol calcium dose (total intake 30 mmol/day). RESULTS: Calcium excretion from several combinations of the urine collections was examined in relation to FCA. The most predictive of FCA was calcium excretion 4 h following the calcium dose. This measure was significantly correlated with FCA (r = 0.735, P = 0.010), fitting 54% of the variability in FCA. CONCLUSION: Urinary calcium excretion during the 4 h after a 10-mmol calcium dose is a useful index of calcium absorption among older adults consuming recommended calcium intakes. This test is inexpensive, easy to implement and potentially useful in large clinical studies.


Asunto(s)
Calcio de la Dieta/farmacocinética , Técnicas de Diagnóstico Endocrino , Indicadores de Salud , Salud , Absorción , Anciano , Algoritmos , Isótopos de Calcio/análisis , Isótopos de Calcio/sangre , Isótopos de Calcio/farmacocinética , Isótopos de Calcio/orina , Calcio de la Dieta/análisis , Calcio de la Dieta/sangre , Calcio de la Dieta/orina , Análisis Costo-Beneficio , Técnicas de Diagnóstico Endocrino/economía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Osteoporosis/diagnóstico , Osteoporosis/metabolismo , Hormona Paratiroidea/sangre , Placebos
10.
BMC Pediatr ; 10: 2, 2010 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-20092618

RESUMEN

BACKGROUND: Central adiposity is related to chronic disease risk in adolescents. Racial differences in waist circumference have been identified using cross-sectional data from this age group. We tested for racial differences in age-related growth in waist circumference in a longitudinal cohort of black and white adolescent girls. METHODS: We analyzed 9 years of publicly available data from the National Heart, Lung, and Blood Institute Growth and Health Study, for 2379 girls (1213 black and 1166 white) enrolled at age 9-10 years in 1987-1988 and followed annually. Individual growth trajectories of waist circumference were constructed for girls with >3 annual measures. Mixed models were used to compare changes in waist circumference during adolescence between black and white females. BMI and age at menarche were included in the models. RESULTS: At each age, black females had significantly higher waist circumference. Mean annual increase in waist circumference was significantly higher for black females compared to white females (1.46 cm/yr vs. 1.36 cm/yr, respectively). After adjusting for BMI, the mean annual increase in waist circumference for white females was significantly higher than for black females (0.08 cm/yr vs. -0.07 cm/yr, respectively). These relationships remained significant after adjusting for age at menarche. CONCLUSIONS: Black females had significantly steeper increases in waist circumference over adolescence than white females. After adjusting for BMI and age at menarche, however, the annual increase in waist circumference for black females was significantly shallower than for their white peers. These data suggest racial differences in the deposition of fat over the adolescent period.


Asunto(s)
Tejido Adiposo/anatomía & histología , Desarrollo del Adolescente , Negro o Afroamericano/estadística & datos numéricos , Circunferencia de la Cintura , Población Blanca/estadística & datos numéricos , Adolescente , Índice de Masa Corporal , Niño , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Humanos , Menarquia , Estados Unidos
11.
J Clin Endocrinol Metab ; 94(1): 96-102, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18940881

RESUMEN

CONTEXT: Bicarbonate has been implicated in bone health in older subjects on acid-producing diets in short-term studies. OBJECTIVE: The objective of this study was to determine the effects of potassium bicarbonate and its components on changes in bone resorption and calcium excretion over 3 months in older men and women. DESIGN, PARTICIPANTS, AND INTERVENTION: In this double-blind, controlled trial, 171 men and women age 50 and older were randomized to receive placebo or 67.5 mmol/d of potassium bicarbonate, sodium bicarbonate, or potassium chloride for 3 months. All subjects received calcium (600 mg of calcium as triphosphate) and 525 IU of vitamin D(3) daily. MAIN OUTCOME MEASURES: Twenty-four-hour urinary N-telopeptide and calcium were measured at entry and after 3 months. Changes in these measures were compared across treatment groups in the 162 participants included in the analyses. RESULTS: Bicarbonate affected the study outcomes, whereas potassium did not; the two bicarbonate groups and the two no bicarbonate groups were therefore combined. Subjects taking bicarbonate had significant reductions in urinary N-telopeptide and calcium excretion, when compared with subjects taking no bicarbonate (both before and after adjustment for baseline laboratory value, sex, and changes in urinary sodium and potassium; P = 0.001 for both, adjusted). Potassium supplementation did not significantly affect N-telopeptide or calcium excretion. CONCLUSIONS: Bicarbonate, but not potassium, had a favorable effect on bone resorption and calcium excretion. This suggests that increasing the alkali content of the diet may attenuate bone loss in healthy older adults.


Asunto(s)
Bicarbonatos/administración & dosificación , Resorción Ósea/prevención & control , Calcio/orina , Compuestos de Potasio/administración & dosificación , Anciano , Colágeno Tipo I/orina , Creatinina/orina , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Péptidos/orina , Potasio/sangre
12.
J Clin Endocrinol Metab ; 94(2): 645-53, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19050051

RESUMEN

CONTEXT: Protein is an essential component of muscle and bone. However, the acidic byproducts of protein metabolism may have a negative impact on the musculoskeletal system, particularly in older individuals with declining renal function. OBJECTIVE: We sought to determine whether adding an alkaline salt, potassium bicarbonate (KHCO3), allows protein to have a more favorable net impact on intermediary indices of muscle and bone conservation than it does in the usual acidic environment. DESIGN: We conducted a 41-d randomized, placebo-controlled, double-blind study of KHCO3 or placebo with a 16-d phase-in and two successive 10-d metabolic diets containing low (0.5 g/kg) or high (1.5 g/kg) protein in random order with a 5-d washout between diets. SETTING: The study was conducted in a metabolic research unit. PARTICIPANTS: Nineteen healthy subjects ages 54-82 yr participated. INTERVENTION: KHCO3 (up to 90 mmol/d) or placebo was administered for 41 d. MAIN OUTCOME MEASURES: We measured 24-h urinary nitrogen excretion, IGF-I, 24-h urinary calcium excretion, and fractional calcium absorption. RESULTS: KHCO3 reduced the rise in urinary nitrogen excretion that accompanied an increase in protein intake (P = 0.015) and was associated with higher IGF-I levels on the low-protein diet (P = 0.027) with a similar trend on the high-protein diet (P = 0.050). KHCO3 was also associated with higher fractional calcium absorption on the low-protein diet (P = 0.041) with a similar trend on the high-protein diet (P = 0.064). CONCLUSIONS: In older adults, KHCO3 attenuates the protein-induced rise in urinary nitrogen excretion, and this may be mediated by IGF-I. KHCO3 may also promote calcium absorption independent of the dietary protein content.


Asunto(s)
Bicarbonatos/farmacología , Calcio/metabolismo , Dieta , Absorción Intestinal/efectos de los fármacos , Nitrógeno/orina , Compuestos de Potasio/farmacología , Proteínas/farmacología , Anciano , Anciano de 80 o más Años , Algoritmos , Bicarbonatos/administración & dosificación , Bicarbonatos/efectos adversos , Suplementos Dietéticos/efectos adversos , Método Doble Ciego , Regulación hacia Abajo/efectos de los fármacos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Nitrógeno/metabolismo , Placebos , Compuestos de Potasio/administración & dosificación , Compuestos de Potasio/efectos adversos
13.
Am J Epidemiol ; 170(1): 37-45, 2009 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-19429876

RESUMEN

The ability to interpret epidemiologic observations is limited because of potential residual confounding by correlated dietary components. Dietary pattern analyses by factor analysis or partial least squares may overcome the limitation. To examine confounding by dietary pattern as well as standard risk factors and selected nutrients, the authors modeled the longitudinal association between alcohol consumption and 7-year risk of type 2 diabetes mellitus in 2,879 healthy adults enrolled in the Framingham Offspring Study (1991-2001) by Cox proportional hazard models. After adjustment for standard risk factors, consumers of > or =9.0 drinks/week had a significantly lower risk of type 2 diabetes mellitus compared with abstainers (hazard ratio = 0.47, 95% confidence interval (CI): 0.27, 0.81). Adjustment for selected nutrients had little effect on the hazard ratio, whereas adjustment for dietary pattern variables by factor analysis significantly shifted the hazard ratio away from null (hazard ratio = 0.33, 95% CI: 0.17, 0.64) by 40.0% (95% CI: 16.8, 57.0; P = 0.002). Dietary pattern variables by partial least squares showed similar results. Therefore, the observed inverse association, consistent with past studies, was confounded by dietary patterns, and this confounding was not captured by individual nutrient adjustment. The data suggest that alcohol intake, not dietary patterns associated with alcohol intake, is responsible for the observed inverse association with type 2 diabetes mellitus risk.


Asunto(s)
Consumo de Bebidas Alcohólicas/efectos adversos , Glucemia/metabolismo , Diabetes Mellitus Tipo 2/epidemiología , Dieta/normas , Conducta Alimentaria , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/prevención & control , Femenino , Estudios de Seguimiento , Humanos , Masculino , Massachusetts/epidemiología , Persona de Mediana Edad , Morbilidad/tendencias , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Factores de Riesgo , Encuestas y Cuestionarios , Factores de Tiempo
14.
J Nutr ; 139(1): 113-9, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19056665

RESUMEN

The proportion of the Latin American population above age 65 y is expected to rise substantially. To better define the prevalence of infectious diseases and micronutrient deficiencies, assess immunological status, and evaluate associations between nutritional status and infection, we performed a cross-sectional study of elderly Ecuadorians in a low-income peri-urban community in Quito, Ecuador. Culturally adapted questionnaires, delayed type hypersensitivity (DTH) skin response, micronutrient, and immunological assays were performed in randomly selected Ecuadorians aged > or = 65 y. Multiple linear and logistic regression models were developed to assess relationships between micronutrient concentrations and history of infection, DTH, and immune function. Participants (n = 352; mean age +/- SD, 74.4 +/- 6.4 y) recalled recent episodes of colds/influenza-like syndromes (62.8%), cough (61.0%), urinary tract infection (37.9%), diarrhea (32.2%), fever (24.1%), and pneumonia (3.5%). A prospective substudy of respiratory infections (RI) in 203 elderly revealed similar findings. Colds and pneumonia occurred in 42.8 and 7.9% of participants, respectively, during 737 person-weeks of observation (3.6 +/- 1.1 wk per person). Anemia and micronutrient deficiencies, especially for vitamins C, D, B-6, and B-12 and folic acid and zinc, were common. Plasma vitamin C was associated with interferon-gamma (IFNgamma) (P < 0.01) and zinc with IFNgamma and interleukin-2 (each P < 0.0001). RI history was associated with any micronutrient deficiency (P < 0.001). The burden of infectious diseases, micronutrient deficiencies, and anemia was substantial in this elderly Ecuadorian population. Deficiencies of essential vitamins and minerals place these elderly adults at risk for infections through their negative impact on immune function.


Asunto(s)
Micronutrientes/deficiencia , Infecciones del Sistema Respiratorio/epidemiología , Infecciones del Sistema Respiratorio/inmunología , Anciano , Anciano de 80 o más Años , Estudios Transversales , Recolección de Datos , Diarrea/complicaciones , Ecuador , Femenino , Humanos , Hipersensibilidad Tardía/epidemiología , Hipersensibilidad Tardía/inmunología , Inmunidad Innata , Modelos Logísticos , Masculino , Desnutrición , Micronutrientes/sangre , Oportunidad Relativa , Infecciones del Sistema Respiratorio/complicaciones , Pruebas Cutáneas , Encuestas y Cuestionarios
15.
Neuron ; 42(5): 717-30, 2004 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-15182713

RESUMEN

Ephrin-As act as retinal topographic mapping labels, but the molecular basis for two key aspects of mapping remains unclear. First, although mapping is believed to require balanced opposing forces, ephrin-As have been reported to be retinal axon repellents, and the counterbalanced force has not been molecularly identified. Second, although graded responsiveness across the retina is required for smooth mapping, a sharp discontinuity has instead been reported. Here, an axon growth assay was developed to systematically vary both retinal position and ephrin concentration and test responses quantitatively. Responses varied continuously with retinal position, fulfilling the requirement for smooth mapping. Ephrin-A2 inhibited growth at high concentrations but promoted growth at lower concentrations. Moreover, the concentration producing a transition from promotion to inhibition varied topographically with retinal position. These results lead directly to a mapping model where position within a concentration gradient may be specified at the neutral point between growth promotion and inhibition.


Asunto(s)
Axones/fisiología , Efrinas/fisiología , Inhibición Neural/fisiología , Retina/fisiología , Vías Visuales/fisiología , Animales , Axones/efectos de los fármacos , Western Blotting/métodos , Tipificación del Cuerpo/fisiología , Mapeo Encefálico , Línea Celular , Embrión de Pollo , Diagnóstico por Imagen/métodos , Relación Dosis-Respuesta a Droga , Embrión de Mamíferos , Efrina-A2/química , Efrina-A2/metabolismo , Efrina-A2/farmacología , Efrina-A5/metabolismo , Efrina-A5/farmacología , Efrinas/clasificación , Fibroblastos , Regulación del Desarrollo de la Expresión Génica , Conos de Crecimiento/efectos de los fármacos , Humanos , Hibridación in Situ/métodos , Técnicas In Vitro , Riñón , Inhibición Neural/efectos de los fármacos , Redes Neurales de la Computación , Ratas , Retina/anatomía & histología , Retina/efectos de los fármacos , Retina/crecimiento & desarrollo , Colículos Superiores/citología , Colículos Superiores/embriología , Colículos Superiores/metabolismo , Factores de Tiempo , Transfección/métodos
16.
J Am Coll Nutr ; 27(2): 274-9, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18689559

RESUMEN

BACKGROUND: Vitamin D insufficiency is prevalent in the northeast United States. Since vitamin D insufficiency is readily amenable to supplementation, it is important to understand what factors are associated with serum 25 hydroxy vitamin D (25(OH)D) response to vitamin D supplementation. OBJECTIVE: In this study we examined the association of serum 25(OH)D response to vitamin D supplementation with body size in a population of elderly subjects. METHODS: 257 healthy, ambulatory men and women 65 years of age or older were randomly assigned to treatment with either 700 IU/day (17.5 microg/d) of supplemental vitamin D(3) and 500 mg/day (12.5 mmol/d) of supplemental calcium, or to placebo. RESULTS: In multivariate regression analyses, after adjusting for baseline 25(OH)D, season, and sex, we found change in 25(OH)D to be inversely associated with baseline BMI (p = 0.01) in subjects treated with supplements for one year. Change in 25(OH)D was also negatively associated with other baseline anthropometric measurements in these subjects. CONCLUSION: Our study implies that body size should be taken into account when estimating the amount of vitamin D intake needed to raise 25(OH)D to the desired level.


Asunto(s)
Índice de Masa Corporal , Colecalciferol/administración & dosificación , Vitamina D/análogos & derivados , Absorciometría de Fotón , Anciano , Anciano de 80 o más Años , Composición Corporal/efectos de los fármacos , Composición Corporal/fisiología , Suplementos Dietéticos , Femenino , Humanos , Masculino , Análisis Multivariante , Análisis de Regresión , Estaciones del Año , Vitamina D/sangre
17.
Biofactors ; 33(3): 191-200, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-19478423

RESUMEN

Vitamin E supplementation has been suggested to improve immune response in the aged in part by altering cytokine production. However, there is not a consensus regarding the effect of supplemental vitamin E on cytokine production in humans. There is evidence that baseline immune health can affect immune response to supplemental vitamin E in the elderly. Thus, the effect of vitamin E on cytokines may depend on their pre-supplementation cytokine response. Using data from a vitamin E intervention in elderly nursing home residents, we examined if the effect of vitamin E on ex vivo cytokine production of IL-1 beta, IL-6, TNF-alpha, and IFN-gamma depended on baseline cytokine production. We observed that the effect of vitamin E supplementation on cytokine production depended on pre-supplementation production of the respective cytokines. The interactions between vitamin E and baseline cytokine production were not explained by covariates known to impact cytokine production. Our results offer evidence that baseline cytokine production should be considered in studies that examine the effect of supplemental vitamin E on immune and inflammatory responses. Our results could have implications in designing clinical trials to determine the impact of vitamin E on conditions in which cytokines are implicated such as infections and atherosclerotic disease.


Asunto(s)
Citocinas/biosíntesis , Vitamina E/uso terapéutico , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Interferón gamma/biosíntesis , Interleucina-1beta/biosíntesis , Interleucina-6/biosíntesis , Masculino , Factor de Necrosis Tumoral alfa/biosíntesis
18.
Am J Clin Nutr ; 86(4): 1167-73, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17921398

RESUMEN

BACKGROUND: Zinc plays an important role in immune function. The association between serum zinc and pneumonia in the elderly has not been studied. OBJECTIVE: The objective was to determine whether serum zinc concentrations in nursing home elderly are associated with the incidence and duration of pneumonia, total and duration of antibiotic use, and pneumonia-associated and all-cause mortality. DESIGN: This observational study was conducted in residents from 33 nursing homes in Boston, MA, who participated in a 1-y randomized, double-blind, and placebo-controlled vitamin E supplementation trial; all were given daily doses of 50% of the recommended dietary allowance of essential vitamins and minerals, including zinc. Participants with baseline (n = 578) or final (n = 420) serum zinc concentrations were categorized as having low (<70 microg/dL) or normal (>or=70 microg/dL) serum zinc concentrations. Outcome measures included the incidence and number of days with pneumonia, number of new antibiotic prescriptions, days of antibiotic use, death due to pneumonia, and all-cause mortality. RESULTS: Compared with subjects with low zinc concentrations, subjects with normal final serum zinc concentrations had a lower incidence of pneumonia, fewer (by almost 50%) new antibiotic prescriptions, a shorter duration of pneumonia, and fewer days of antibiotic use (3.9 d compared with 2.6 d) (P

Asunto(s)
Hogares para Ancianos , Casas de Salud , Neumonía/sangre , Neumonía/epidemiología , Vitamina E/administración & dosificación , Zinc/sangre , Anciano , Anciano de 80 o más Años , Antibacterianos/uso terapéutico , Boston/epidemiología , Causas de Muerte , Suplementos Dietéticos , Método Doble Ciego , Femenino , Humanos , Incidencia , Masculino , Estado Nutricional , Neumonía/tratamiento farmacológico , Neumonía/mortalidad , Factores de Tiempo , Vitaminas/administración & dosificación , Zinc/inmunología
19.
Am J Clin Nutr ; 85(4): 1023-30, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17413101

RESUMEN

BACKGROUND: There remains no consensus about the optimal dietary composition for sustained weight loss. OBJECTIVE: The objective was to examine the effects of 2 dietary macronutrient patterns with different glycemic loads on adherence to a prescribed regimen of calorie restriction (CR), weight and fat loss, and related variables. DESIGN: A randomized controlled trial (RCT) of diets with a high glycemic load (HG) or a low glycemic load (LG) at 30% CR was conducted in 34 healthy overweight adults with a mean (+/-SD) age of 35 +/- 6 y and body mass index (kg/m(2)) of 27.6 +/- 1.4. All food was provided for 6 mo in diets controlled for confounding variables, and subjects self-administered the plans for 6 additional months. Primary and secondary outcomes included energy intake measured by doubly labeled water, body weight and fatness, hunger, satiety, and resting metabolic rate. RESULTS: All groups consumed significantly less energy during CR than at baseline (P < 0.01), but changes in energy intake, body weight, body fat, and resting metabolic rate did not differ significantly between groups. Both groups ate more energy than provided (eg, 21% and 28% CR at 3 mo and 16% and 17% CR at 6 mo with HG and LG, respectively). Percentage weight change at 12 mo was -8.04 +/- 4.1% in the HG group and -7.81 +/- 5.0% in the LG group. There was no effect of dietary composition on changes in hunger, satiety, or satisfaction with the amount and type of provided food during CR. CONCLUSIONS: These findings provide more detailed evidence to suggest that diets differing substantially in glycemic load induce comparable long-term weight loss.


Asunto(s)
Composición Corporal/fisiología , Dieta Reductora , Metabolismo Energético/fisiología , Índice Glucémico/fisiología , Obesidad/dietoterapia , Cooperación del Paciente , Tejido Adiposo/metabolismo , Adulto , Metabolismo Basal/fisiología , Ingestión de Energía/fisiología , Femenino , Humanos , Masculino , Saciedad/efectos de los fármacos , Saciedad/fisiología , Pérdida de Peso
20.
Pediatr Crit Care Med ; 8(3): 264-7, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-17417117

RESUMEN

OBJECTIVE: To assess the measured resting energy expenditure pattern over time in a group of critically ill children who were admitted to a pediatric intensive care unit and to determine whether a hypermetabolic response, i.e., >10% above predicted, occurred in a pattern similar to that observed in adults. A secondary aim was to compare the accuracy of a newly derived prediction equation specific to the pediatric intensive care unit and the measured resting energy expenditure. DESIGN: A prospective, clinical, observational study. SETTING: A pediatric intensive care unit of a tertiary care medical center. PATIENTS: Forty-four children (29 males, 15 females) ages 2 wks to 17 yrs. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: During the course of their stay in the pediatric intensive care unit, 44 patients' measured resting energy expenditure was assessed using indirect calorimetry 94 times at up to three time points. The first measurement was at a mean time of 25 +/- 10 (+/-sd) hrs after admission, the second at 73 +/- 16 hrs, and the third immediately before discharge, which occurred at a mean of 193 +/- 93 hrs after admission. Measured energy expenditure varied only slightly (7% to 10%) from the first to second and the second to third measurements. Evidence for hypermetabolism was not apparent. Generally, the prediction equations performed well. Mean measured resting energy expenditure for all measurements was 821 +/- 653 kcals/24 hrs. The Schofield equation estimate was 798 +/- 595 kcals/24 hrs and the White equation estimate was 815 +/- 564 kcals/24 hrs (p = not significant). Nineteen (20%) measurements were >110% above the age-appropriate Schofield-predicted equation, and 30 measurements (32%) were <90% below that predicted by Schofield. Consequently, 45% of measured resting energy expenditure measurements were within 90% to 110% of that predicted by the Schofield equation. The White equation was inaccurate (not within 10% of measured resting energy expenditure) in 66 of 94 measurements (70%). The discrepancy was greatest (100%) in children with measured resting energy expenditure <450 kcal/24 hrs. CONCLUSION: The hypermetabolic response apparent in adults was not evident in these critically ill children. Currently available prediction equations cannot substitute for indirect calorimetry measurement of energy expenditure in guiding nutritional support in pediatric intensive care units.


Asunto(s)
Enfermedad Crítica , Metabolismo Energético/fisiología , Adolescente , Metabolismo Basal/fisiología , Calorimetría Indirecta , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Unidades de Cuidado Intensivo Pediátrico , Masculino , Estudios Prospectivos
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