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Biomedical subjects

Kathryn G Dewey

Publications and source records attributed to Kathryn G Dewey.

At least 19 recordsLinked to original sources
PubMed2006

Effect of timing of umbilical cord clamping on iron status in Mexican infants: a randomised controlled trial.

BACKGROUND: Delayed clamping of the umbilical cord increases the infant's iron endowment at birth and haemoglobin concentration at 2 months of age. We aimed to assess whether a 2-minute delay in the clamping of the umbilical cord of normal-weight, full-term infants improved iron and haematological status up to 6 months of age. METHODS: 476 mother-infant pairs were recruited at a large obstetrics hospital in Mexico City, Mexico, randomly assigned to delayed clamping (2 min after delivery of the infant's shoulders) or early clamping (around 10 s after delivery), and followed up until 6 months postpartum. Primary outcomes were infant haematological status and iron status at 6 months of age, and analysis was by intention-to-treat. This study is registered with ClinicalTrials.gov, number NCT00298051. FINDINGS: 358 (75%) mother-infant pairs completed the trial. At 6 months of age, infants who had delayed clamping had significantly higher mean corpuscular volume (81.0 fL vs 79.5 fL 95% CI -2.5 to -0.6, p=0.001), ferritin (50.7 mug/L vs 34.4 mug/L 95% CI -30.7 to -1.9, p=0.0002), and total body iron. The effect of delayed clamping was significantly greater for infants born to mothers with low ferritin at delivery, breastfed infants not receiving iron-fortified milk or formula, and infants born with birthweight between 2500 g and 3000 g. A cord clamping delay of 2 minutes increased 6-month iron stores by about 27-47 mg. INTERPRETATION: Delay in cord clamping of 2 minutes could help prevent iron deficiency from developing before 6 months of age, when iron-fortified complementary foods could be introduced.

Adult↗
PubMed2006

Effects of varied energy density of complementary foods on breast-milk intakes and total energy consumption by healthy, breastfed Bangladeshi children.

BACKGROUND: Information is needed to design studies of the effects of complementary feeding regimens on children's intakes of complementary foods (CFs) and breast milk. OBJECTIVE: We evaluated the effects of varied energy density of CFs on the time until stabilization of dietary intakes and on total daily energy intakes (EIs) and breast-milk intakes. DESIGN: CFs with low [0.4 kcal/g (LD)] and high [1.5 kcal/g (HD)] energy density were fed 3 times/d to 10 children (aged 9-18 mo) during 2 randomly assigned sequences of three 8-d diet periods (HD-LD-HD or LD-HD-LD) along with ad libitum breastfeeding. CF and breast-milk intakes were measured. RESULTS: Intakes of the HD diet and breast milk did not vary by day of period, but intake of the LD diet increased progressively. During days 5-7 of the last 2 diet periods in each sequence, more of the LD than of the HD diet was consumed (752 +/- 252 and 439 +/- 111 g/d, respectively; P < 0.001), but EIs from CFs were greater with the HD diet. Breast-milk consumption was slightly less (192 +/- 115 and 234 +/- 121 g/d, respectively; P = 0.03) but total daily EI was greater (774 +/- 175 and 441 +/- 85 kcal/d, respectively; P < 0.001) during the HD than during the LD diet period. CONCLUSIONS: New information on the effects of newly introduced diets on daily intakes of these diets and of breast milk can be used to design future studies. Total daily EIs were greater with the HD diet despite its negative effects on breast-milk intakes.

Adaptation, Physiological↗
PubMed2006

Zinc supplementation does not affect growth, morbidity, or motor development of US term breastfed infants at 4-10 mo of age.

BACKGROUND: It has been documented that growth patterns differ between breastfed and formula-fed infants. Some investigators have suggested that these differences may be related to differences in zinc nutriture. OBJECTIVE: The objective of this study was to examine the effect of zinc supplementation on growth, morbidity, and motor development in healthy, term, breastfed infants. DESIGN: We conducted a randomized double-blind intervention comparing zinc supplementation (5 mg/d as zinc sulfate) with placebo in breastfed infants aged 4-10 mo. Growth and indexes of body composition and gross motor development were measured monthly from 3 to 10 mo. Morbidity data were collected weekly. RESULTS: Eighty-five infants were enrolled, and 70 completed the study. The baseline characteristics, attained weight or length at 10 mo, growth velocity, gross motor development, and morbidity did not differ significantly between groups, even after control for potentially confounding variables. CONCLUSIONS: The dietary zinc intake of these breastfed infants appeared to be adequate, given that zinc supplementation did not affect growth, development, or risk of infection (although sample size for detection of differences in development or infection was limited). Previously described differences in growth between breastfed and formula-fed infants in such populations do not appear to be due to differences in zinc nutriture.

Analysis of Variance↗
PubMed2006

What is the optimal age for introduction of complementary foods?

In 2001, a WHO Expert Consultation concluded that waiting until 6 months to introduce complementary foods to breastfed infants confers several benefits for both infants and mothers. Nonetheless, there is still controversy about this issue. In developing countries, the reduced risk of infant gastrointestinal illness and increased duration of maternal lactational amenorrhea associated with exclusive breastfeeding for 6 months make the benefit-risk ratio of this recommendation highly favorable. In industrialized countries, the case is less clear-cut, but the benefit-risk ratio is also likely to be favorable with regard to infant infectious morbidity, motor development and maternal weight loss postpartum. For outcomes such as infant growth, food acceptance and iron or zinc status, the evidence for industrialized countries suggests no particular benefit but also very little risk of following this recommendation. Some exclusively breastfed infants may become iron- or zinc-deficient before 6 months, but this can be prevented more effectively by targeted iron and zinc supplementation to high-risk infants than by introducing complementary foods. On the whole, the evidence to date supports the WHO recommendation to introduce complementary foods at 6 months, but further research in industrialized countries would be useful.

Age Factors↗
PubMed2005

Iron supplements reduce erythrocyte copper-zinc superoxide dismutase activity in term, breastfed infants.

AIM: To investigate whether iron supplements compromise copper status in infants. METHODS: 214 healthy, term, breastfed Swedish and Honduran infants were randomized to (1) iron supplements (1 mg/kg/d) from 4-9 mo of age, (2) iron supplements from 6-9 mo, or (3) placebo. Blood samples were obtained at 4, 6, and 9 mo and analyzed for plasma copper (p-Cu) and, at 9 mo, for copper/zinc-dependent superoxide dismutase (CuZn-SOD) activity. RESULTS: P-Cu increased with infant age. At 9 mo, Honduran infants had significantly higher p-Cu (1.40+/-0.29 vs 1.09+/-0.22 mg/l, p<0.001) and CuZn-SOD activity (1.09+/-0.29 vs 0.93+/-0.21 U/mg Hb, p<0.001) than Swedish infants. Infants receiving iron supplements from 4-9 mo had significantly lower CuZn-SOD at 9 mo of age (0.95+/-0.27 vs 1.08+/-0.24 U/mg Hb, p=0.023) than those receiving placebo. CONCLUSION: There is a physiologic increase in p-Cu during the first 9 mo of life. Differences in copper status between Swedish and Honduran infants may be due to genetic or nutritional differences. Iron supplementation decreases CuZn-SOD activity, probably due to a negative effect on copper status. Possible clinical implications remain to be elucidated.

Adult↗
PubMed2005

Anemia, iron deficiency, and iron deficiency anemia in 12-36-mo-old children from low-income families.

BACKGROUND: Iron deficiency (ID) is the most common nutritional deficiency in the world and remains relatively common in at-risk groups in the United States. The actual prevalence of anemia, ID, and iron deficiency anemia (IDA) in California remains unclear. OBJECTIVE: The objective was to determine the prevalence of anemia, low iron stores, ID, and IDA in children participating in the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) population, and to assess the value of using hemoglobin to predict ID. DESIGN: This was a cross-sectional study of a convenience sample of 12-36-mo-old children from WIC clinics in 2 California counties. RESULTS: The prevalence of anemia was 11.1% (hemoglobin <110 g/L at 12-24 mo or <111 g/L at 24-36 mo). Study- and literature-determined abnormal values for iron measures were as follows: serum ferritin or=8.4 or >10.0 microg/mL, and transferrin saturation or=2 abnormal iron measures) were 16.2% and 8.8%, and of IDA (ID with low hemoglobin) were 3.4% and 3.2% on the basis of study- and literature-determined cutoffs, respectively. Hemoglobin concentration was used to predict study- and literature-determined ID on the basis of receiver operating characteristic curves. The sensitivity of low hemoglobin in predicting study- and literature-determined ID was low (23.2% and 40.0%, respectively). CONCLUSIONS: Anemia and ID were prevalent in this WIC sample, but IDA was uncommon. Low hemoglobin is a poor predictor of ID.

Anemia↗
PubMed2005

Low nutrient intakes among infants in rural Bangladesh are attributable to low intake and micronutrient density of complementary foods.

We assessed the adequacy of nutrient intakes of 135 rural Bangladeshi breast-fed infants 6-12 mo of age and examined nutritional trade-offs due to possible displacement of breast milk by complementary foods. Observers completed 12-h daytime measurements of breast milk and complementary food intakes; data for the previous 12 h were obtained from maternal recall, yielding estimates of total 24-h intakes. On average, infants were mildly wasted (mean +/- SD weight-for-length Z-score = -0.92 +/- 0.88) and moderately stunted (length-for-age Z-score = -1.49 +/- 0.96). Total energy intakes at 6-8 and 9-12 mo were 88 and 86% of absolute energy requirements (kJ/d), 106 and 105% of requirements per kg body weight, and 97 and 94% of requirements per kg median weight-for-length, respectively. Breast milk contributed 78% of energy intake at 6-8 mo and 75% at 9-12 mo. Mean meal frequency and energy density of complementary foods were generally consistent with recommendations, but only small amounts of food were offered. Nevertheless, only 72% of the food energy offered was consumed. Total energy intake was positively correlated with meal frequency, quantity consumed per meal, and energy intake from breast milk, but not with energy density of complementary foods. Energy intake from complementary foods was inversely related to energy intake from breast milk. The diets fell short of recommended intakes for numerous vitamins and minerals. We conclude that although greater intakes of complementary foods were associated with higher total energy intake, micronutrient intake remained low due to the low micronutrient density of the complementary foods consumed and the partial displacement of breast milk.

Bangladesh↗
PubMed2005

Infant weight-for-length is positively associated with subsequent linear growth across four different populations.

Several studies have documented that length gain often lags behind weight gain during infancy and early childhood, suggesting that linear growth is partly regulated by initial body mass or fatness. To investigate this hypothesis, we analysed data from four longitudinal studies on growth of infants in the first 12 months: (1) U.S. breast-fed and formula-fed infants (n = 89); (2) breast-fed infants in Ghana (n = 190); (3) normal birthweight, breast-fed infants in Honduras (n = 108); and (4) term, low-birthweight breast-fed infants in Honduras (n = 119). The dependent variable was length gain during each 3-month interval (1- 4, 2-5, 3-6, 4-7, 5-8, 6-9, 7-10, 8-11 and 9-12 months). Three main independent variables were examined: initial weight-for-length z-score (W/L), weight change during the prior 3 months, and initial skinfold thickness. Controlling for maternal height, infant sex, and initial length-for-age z-score, length gain was positively correlated with initial W/L and prior weight change during all age intervals and with initial skinfold thickness at 3 and 4 months (r = 0.15-0.36; P < 0.01). There was no evidence of a threshold effect. These associations were evident in all four populations, in both boys and girls, and in breast-fed and formula-fed infants. The consistency of this relationship across studies supports the hypothesis that linear growth is partly regulated by initial body mass or fatness in infants.

Adipose Tissue↗
PubMed2004

Impact of breastfeeding on maternal nutritional status.

This review covers the impact of breastfeeding on maternal postpartum weight loss and micronutrient status. Results regarding the impact on weight loss have been conflicting. This may be due to differences in study quality. Of six observational studies in which postpartum weight change was estimated (rather than measured directly), only one showed an association with breastfeeding. By contrast, six of the seven studies in which postpartum weight change was measured showed greater weight or fat loss in women who breastfed longer, particularly at 3 to 6 months postpartum. The results of the higher quality studies are consistent with two experimental studies conducted in Honduras, which demonstrated that the degree of breastfeeding affects the rate of weight loss. Thus, it appears that breastfeeding does enhance the rate of weight loss postpartum, but the effect is relatively small and may not be detectable in studies that lack adequate statistical power, have imprecise data on postpartum weight change, or do not account for the exclusivity and/or duration of breastfeeding. There is very little information with regard to micronutrient status during lactation. Nutrient requirements for vitamins A, B6, and C, and for iodine and zinc are increased by more than 50%, but lactation may actually be protective against maternal iron deficiency. More research is needed on the effects of lactation on maternal nutritional status and on strategies for optimizing nutrient intake to meet the needs of both the mother and her infant.

Adult↗
PubMed2004

Iron, zinc, and copper concentrations in breast milk are independent of maternal mineral status.

BACKGROUND: Little is known about the regulation of iron, zinc, and copper in breast milk and the transport of these minerals across the mammary gland epithelium. OBJECTIVE: The objective was to study associations between breast-milk concentrations of iron, zinc, and copper and maternal mineral status. DESIGN: Milk samples from 191 Swedish and Honduran mothers were collected at 9 mo postpartum. Iron, zinc, and copper concentrations were measured by atomic absorption spectrometry. Blood samples from mothers were analyzed for plasma zinc and copper and 4 indexes of iron status: hemoglobin, plasma ferritin, soluble transferrin receptors, and zinc protoporphyrin. Complementary food energy (CFE) intake was used as an inverse proxy for breast-milk intake. RESULTS: Mean (+/-SD) breast-milk concentrations of iron were lower in the Honduran than in the Swedish mothers (0.21 +/- 0.25 compared with 0.29 +/- 0.21 mg/L; P < 0.001), and mean breast-milk concentrations of zinc and copper were higher in the Honduran than in the Swedish mothers [0.70 +/- 0.18 compared with 0.46 +/- 0.26 mg/L (P < 0.001) and 0.16 +/- 0.21 compared with 0.12 +/- 0.22 mg/L (P = 0.001), respectively]. Milk iron was positively correlated with CFE intake (r = 0.24, P = 0.001) but was not significantly correlated with any iron-status variable. Milk zinc was negatively correlated with CFE intake (r = -0.24, P = 0.001) but was not significantly correlated with maternal plasma zinc. Milk copper was not significantly correlated with CFE intake or maternal plasma copper. CONCLUSIONS: Milk iron, zinc, and copper concentrations at 9 mo postpartum are not associated with maternal mineral status, which suggests active transport mechanisms in the mammary gland for all 3 minerals. Milk iron concentrations increase and milk zinc concentrations decrease during weaning [corrected]

Adult↗
PubMed2004

Validation of a new pediatric air-displacement plethysmograph for assessing body composition in infants.

BACKGROUND: The accurate measurement of body composition is useful in assessments of infant growth and nutritional status. OBJECTIVE: This study evaluated the reliability and accuracy of a new air-displacement plethysmography (ADP) system for body-composition assessment in infants. DESIGN: Between- and within-day reliability was assessed by comparing the percentage body fat (%BF) obtained on consecutive days and on the same day, respectively, in 36 full-term infants. Accuracy was assessed by comparing %BF measured with the use of ADP and %BF measured with the use of deuterium (2H2O) dilution in 53 infants. RESULTS: There were no significant differences in %BF between days (-0.50 +/- 1.21%BF) or within days (0.16 +/- 1.44%BF). Mean between- and within-day test-retest SDs of 0.69 and 0.72%BF, respectively, indicated excellent reliability. The %BF measurements obtained by using ADP were not significantly influenced by infant behavioral state. Mean %BF obtained by using ADP (20.32%BF) did not differ significantly from that obtained by using 2H2O dilution (20.39%BF), and the regression line [%BF(2H2O) = 0.851%BF (ADP) + 3.094] gave a high R2 (0.76) and a low SEE (3.26). The 95% limits of agreement between ADP and 2H2O (-6.84%BF, 6.71%BF) were narrower than those reported for other body-composition techniques used in infants. Individual differences between the 2 methods were not a function of body mass or fatness. CONCLUSION: ADP is a reliable and accurate instrument for determining %BF in infants, and it has the potential for use in both research and clinical settings.

Body Composition↗
PubMed2004

Exclusive breast-feeding for 6 months, with iron supplementation, maintains adequate micronutrient status among term, low-birthweight, breast-fed infants in Honduras.

There is little information on the risk of micronutrient deficiencies during the period of exclusive breast-feeding. We evaluated this among term, low-birthweight (LBW; 1500-2500 g) infants in Honduras. Mother-infant pairs were recruited in the hospital and assisted with exclusive breast-feeding during the first 4 mo. At 4 mo, infants were randomly assigned to either continue exclusive breast-feeding to 6 mo (EBF; n = 59) or be given iron-fortified complementary foods (rice, chicken, fruits, and vegetables) from 4 to 6 mo while continuing to breast-feed (SF, n = 60). Blood samples were collected at 2, 4, and 6 mo and analyzed for hemoglobin (Hb), hematocrit, plasma ferritin, % transferrin saturation, vitamin A, vitamin B-12, folate, zinc, and erythrocyte folate. Infants with Hb < 100 g/L at 2 or 4 mo were given medicinal iron supplements for 2 mo; the proportion administered iron drops did not differ significantly between groups. There was no significant effect of complementary foods on indices of vitamin A, B-12, folate, or zinc status. Among infants not given medicinal iron at 4-6 mo, iron status was higher in the SF group than the EBF group. In those given medicinal iron at 4-6 mo, iron status was higher in the EBF group, suggesting that complementary foods interfered with iron utilization. About half of the infants were anemic by 2 mo, before the age when complementary foods would be recommended. This supports the recommendation that LBW infants should receive iron supplementation in early infancy. Given that infants given iron supplements did not benefit from complementary foods at 4-6 mo, we conclude that exclusive breast-feeding for 6 mo (with iron supplementation) can be recommended for term, LBW infants.

Anemia↗
PubMed2004

Diagnostic value of signs and symptoms of mammary candidosis among lactating women.

Mammary candidosis in lactating women is not well defined and is most often presumptively diagnosed by signs and symptoms. This study evaluates the sensitivity, specificity, positive predictive value, and likelihood ratios of signs and symptoms of mammary candidosis based on the presence of Candida species on the nipple/areola or in the milk. In this prospective cohort study, the nipple/areola skin and milk of 100 healthy breastfeeding mothers were cultured from each breast at 2 weeks postpartum, and mothers were interviewed regarding signs and symptoms associated with mammary candidosis between 2 and 9 weeks postpartum. Positive predictive value for Candida colonization was highest when there were 3 or more signs or symptoms simultaneously or when flaky or shiny skin of the nipple/areola was reported together or in combination with breast pain.

Adult↗
PubMed2004

Behavior-change trials to assess the feasibility of improving complementary feeding practices and micronutrient intake of infants in rural Bangladesh.

This study used simple rapid-assessment techniques to test the feasibility of increasing the consumption of complementary foods by infants by asking mothers to increase meal quantity or frequency or by altering the viscosity/energy density of the food. The feasibility of using micronutrient supplements either added directly to food or administered as liquid drops was also examined. The study was conducted in rural Bangladesh and involved four separate short-term behavioral change trials. Depending on the trial, fieldworkers recruited 30 to 45 infants 6 to 12 months of age. Following recommendations to increase the amount of food provided to infants, the mean intakes from single meals increased from 40 +/- 23 g on day 1 to 64 +/- 30 g on day 7 (p < 0.05). In a second trial, the mean meal frequency increased from 2.2 +/- 1.3 on day 1 to 4.1 +/- 1.3 on day 7 (p < 0.05). Provision of high-energy-density diets, prepared by decreasing viscosity with alpha-amylase or by hand-mashing rice and dhal into a paste before feeding, increased single-meal energy consumption from 54 +/- 35 kcal to 79 +/- 52 kcal or 75 +/- 37 kcal (p < 0.05), respectively. Both types of micronutrient supplements were well accepted and used according to recommendations. In conclusion, it was possible to change short-term child-feeding behaviors to promote increased food intake, mealfrequency, energy density, and micronutrient consumption. Because each of these interventions lasted for only about 1 week, however, the long-term sustainability of these changes is not known. Moreover, the effect of increased feeding of complementary foods on intakes of breastmilk and total daily consumption of energy and nutrients requires further study.

Bangladesh↗
PubMed2004

Implementation of the WHO Multicentre Growth Reference Study in the United States.

The World Health Organization (WHO) Multicentre Growth Reference Study (MRGS) North American site was Davis, California. For the longitudinal cohort (0-24 months), 208 infants were enrolled between January and December 1999 from five area hospitals at which nearly all Davis women give birth. The target sample size was lower in the United States than in the other sites, because recruitment in the United States was restricted to mothers who were willing to exclusively breastfeed for at least 4 months and continue breastfeeding for at least 12 months. For the cross-sectional component, a mixed-longitudinal design was used, which required approximately 500 subjects. The subjects were recruited by going door-to-door, with the sampling scheme based on the distribution of the subjects of the longitudinal study within the city. The cross-sectional sample was recruited between January and July 2001. Major challenges during implementation were maintaining daily communication with hospital personnel and scheduling home visits.

Child Development↗