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Biomedical subjects

K G Dewey

Publications and source records attributed to K G Dewey.

At least 19 recordsLinked to original sources
PubMed2004

Effect of iron supplementation on cognition in Greek preschoolers.

OBJECTIVE: To examine effects of iron supplementation on vigilance, attention and conceptual learning in preschool children in Greece. DESIGN: Randomized Double-Blind Placebo Controlled trial of iron. Randomization stratified by iron status and day care center (DCC). SETTING: Nine public DCCs in Athens, Greece. SUBJECTS: In all, 49 3-4-y olds (21 anemic, 28 good iron status) with birth weight not less than 2500 g, currently healthy; benign past medical history, IQ > or =1 s.d. below the age-adjusted mean, serum Pb < or =200 ppb (none exceeded 50 ppb), and height, weight and head circumference for age > or =10th percentile. Anemia defined as: (1) pretreatment Hgb <112 g/l and TS <16% and ferritin <12 microg/L OR (2) Hgb rise of >10 g/l (T2-T0) with iron supplementation. Good iron status was defined as baseline levels of Hgb >120 g/l and either TS >20% or serum ferritin >12 microg/l. INTERVENTION: The intervention consisted of a 2-month supplementation of 15 mg iron (and MV) vs placebo (MV alone). RESULTS: After iron treatment, the anemic subjects made significantly fewer errors of commission (14% higher specificity, P<0.05), exhibited 8% higher accuracy (P<0.05) and were significantly more efficient (mean difference=1.09, P<0.05) than those given placebo. These effects of iron were not found among preschoolers with good iron status. No effects of iron treatment were found on the Oddity Learning task. CONCLUSIONS: This study demonstrated that iron supplementation of iron-deficient anemic preschoolers results in an improvement in discrimination, specifically selective attention.

Anemia, Iron-Deficiency↗
PubMed2001

Nutrition, growth, and complementary feeding of the breastfed infant.

Although additional research is needed on many of the issues discussed herein, the following conclusions are well substantiated by the evidence available to date: Breast milk alone can meet nutrient needs during the first 6 months, with the possible exception of vitamin D in certain populations and iron in infants of relatively low birth weight. Complementary foods offered before 6 months of age tend to displace breast milk and do not confer any growth advantage over exclusive breastfeeding. Breast milk continues to provide substantial amounts of key nutrients well beyond the first year of life, especially protein, fat, and most vitamins. Breastfed infants tend to gain less weight and usually are leaner than are formula-fed infants in the second half of infancy. This difference does not seem to be the result of nutritional deficits but rather infant self-regulation of energy intake. New growth charts based on infants breastfed throughout the first year of life are being developed by WHO. The nutrients most likely to be limiting in the diets of breastfed infants are minerals, such as iron, zinc, and calcium. Using the following guidelines can help to ensure that the nutrient needs of the breastfed child are met: Continue to breastfeed as often as the infant desires. Aim for a variety of complementary foods, with fruits, vegetables, and animal products (e.g., meat, fish, poultry, or egg) offered daily. Iron-fortified cereals and meats can provide adequate iron. Calcium can be obtained from cheese, yogurt, and other dairy products (although fresh cow's milk is not recommended before 12 mo). Avoid giving too much juice. Be alert to any signs that the child's appetite, growth, or development is impaired. When in doubt, a balanced vitamin-mineral supplement is advisable. Make mealtimes enjoyable.

Biological Availability↗
PubMed2001

Iron supplementation of breast-fed Honduran and Swedish infants from 4 to 9 months of age.

OBJECTIVE: The objective was to study the effects of iron supplementation on hemoglobin and iron status in 2 different populations. STUDY DESIGN: In a randomized, placebo-controlled, masked clinical trial, we assigned term Swedish (n = 101) and Honduran (n = 131) infants to 3 groups at 4 months of age: (1) iron supplements, 1 mg/kg/d, from 4 to 9 months, (2) placebo, 4 to 6 months and iron, 6 to 9 months, and (3) placebo, 4 to 9 months. All infants were breast-fed exclusively to 6 months and partially to 9 months. RESULTS: From 4 to 6 months, the effect of iron (group 1 vs 2 + 3) was significant and similar in both populations for hemoglobin, ferritin, and zinc protoporphyrin. From 6 to 9 months, the effect (group 2 vs group 3) was significant and similar at both sites for all iron status variables except hemoglobin, for which there was a significant effect only in Honduras. In Honduras, the prevalence of iron deficiency anemia at 9 months was 29% in the placebo group and 9% in the supplemented groups. In Sweden, iron supplements caused no reduction in the already low prevalence of iron deficiency anemia at 9 months (<3%). CONCLUSION: Iron supplementation from 4 to 9 months or 6 to 9 months significantly reduced iron deficiency anemia in Honduran breast-fed infants. The unexpected hemoglobin response at 4 to 6 months in both populations suggests that regulation of hemoglobin synthesis is immature at this age.

Age Factors↗
PubMed2001

Maternal and fetal stress are associated with impaired lactogenesis in humans.

Studies in animals indicate that various types of stressful stimuli can depress lactation, but there is much less information in humans. Experimental studies in breastfeeding women have shown that acute physical and mental stress can impair the milk ejection reflex by reducing the release of oxytocin during a feed. If this occurs repeatedly, it could reduce milk production by preventing full emptying of the breast at each feed. Prospective observational studies indicate that both maternal and fetal stress during labor and delivery (e.g., urgent Cesarean sections or long duration of labor in vaginal deliveries) are associated with delayed onset of lactation. The effects of chronic emotional stress on lactation are not known. Mothers who experience high levels of stress during and after childbirth should receive additional lactation guidance during the first week or two postpartum.

Animals↗
PubMed2001

Effects of exclusive breastfeeding for four versus six months on maternal nutritional status and infant motor development: results of two randomized trials in Honduras.

To examine whether the duration of exclusive breastfeeding affects maternal nutrition or infant motor development, we examined data from two studies in Honduras: the first with 141 infants of low-income primiparous women and the second with 119 term, low birth weight infants. In both studies, infants were exclusively breastfed for 4 mo and then randomly assigned to continue exclusive breastfeeding (EBF) until 6 mo or to receive high-quality, hygienic solid foods (SF) in addition to breast milk between 4 and 6 mo. Maternal weight loss between 4 and 6 mo was significantly greater in the exclusive breastfeeding group (EBF) group than in the group(s) given solid foods (SF) in study 1 (-0.7 +/- 1.5 versus -0.1 +/- 1.7 kg, P < 0.05) but not in study 2. The estimated average additional nutritional burden of continuing to exclusively breastfeed until 6 mo was small, representing only 0.1-6.0% of the recommended dietary allowance for energy, vitamin A, calcium and iron. Women in the EBF group were more likely to be amenorrheic at 6 mo than women in the SF group, which conserves nutrients such as iron. In both studies, few women (10-11%) were thin (body mass index <19 kg/m(2)), so the additional weight loss in the EBF group in study 1 was unlikely to have been detrimental. Infants in the EBF group crawled sooner (both studies) and were more likely to be walking by 12 mo (study 1) than infants in the SF group. Taken together with our previous findings, these results indicate that the advantages of exclusive breastfeeding during this interval appear to outweigh any potential disadvantages in this setting.

Amenorrhea↗
PubMed2000

Predictors of growth from 1 to 18 months among breast-fed Ghanaian infants.

OBJECTIVE: To examine factors associated with the physical growth of breast-fed Ghanaian infants during the first 18 months of life. DESIGN: A community-based longitudinal study. SETTING: The study was carried out in Techiman, a district capital and major food trading center in the Brong Ahafo region of Ghana. SUBJECTS: One-month old infants (n=216) with birth weight >/= 2.5 kg were recruited from Maternal and Child Health Centers. METHOD: From 6 to 12 months, infants were provided with one of four types of nutritionally enhanced complementary foods. Anthropometric assessments were completed monthly from 1 to 12 months and every other month from 12 to 18 months. Information was collected on household characteristics, morbidity from common infections and dietary intakes. Blood samples were collected at 6 and 12 months to assess iron, zinc, riboflavin and vitamin A status. Multiple regression analysis was used to examine factors associated with growth during the age intervals of 1-6, 4-6, 6-12 and 12-18 months as well as size attained at 12 and 18 months. RESULTS: Prevalence of diarrhea and fever were negatively associated with growth during the first year of life. No significant relationship was found between respiratory illness (defined as cough or purulent nasal discharge) and growth. With the exception of dietary zinc intake, dietary variables were generally not significantly associated with growth. Maternal education was positively associated with growth during most of the age intervals. CONCLUSION: These findings suggest that interventions to reduce morbidity and improve the education of girls may benefit children's growth in this population. SPONSORSHIP: Nestle Foundation; Rockefeller Foundation African Dissertation Internship Award; Fulbright Scholarship. European Journal of Clinical Nutrition (2000) 54, 41-49

Anthropometry↗
PubMed2000

Exclusively breastfed, low birthweight term infants do not need supplemental water.

UNLABELLED: Breast milk intake, urine volume and urine-specific gravity (USG) of exclusively breastfed, low birthweight (LBW) term male infants in Honduras were measured during 8-h periods at 2 (n = 59) and 8 (n = 68) wk of age. Ambient temperature was 22-36 degrees C and relative humidity was 37-86%. Maximum USG ranged from 1.001 to 1.012, all within normal limits. CONCLUSIONS: We conclude that supplemental water is not required for exclusively breastfed, LBW term infants, even in hot conditions.

Breast Feeding↗
PubMed2000

Predictors of micronutrient status among six- to twelve-month-old breast-fed Ghanaian infants.

This study describes the factors associated with hemoglobin and plasma ferritin, zinc and retinol concentrations and erythrocyte riboflavin status among 208 Ghanaian infants who participated in a complementary feeding intervention trial from 6 to 12 mo of age. Anthropometric, morbidity and dietary data were collected regularly from 1 to 12 mo; blood samples were collected at 6 and 12 mo. The prevalence of low micronutrient status at 6 and 12 mo, respectively, was as follows: hemoglobin <100 g/L, 30 and 34%; plasma ferritin <12 microg/L, 17 and 43%; plasma zinc <10.7 micromol/L, 4 and 6%; plasma retinol <0.7 micromol/L, 26 and 26%; erythrocyte riboflavin <200 umol/L of packed red cells, 14 and 10%. Multiple regression was used to identify factors significantly associated with micronutrient status. From 6 to 12 mo, fever prevalence was associated with a decrease in hemoglobin, but an increase in erythrocyte riboflavin concentrations, and diarrhea prevalence was related to a decrease in plasma retinol. Seasonal differences were evident for most of the indicators of micronutrient status, and elevated C-reactive protein levels (indicative of recent infection) were related to lower hemoglobin, retinol and zinc concentrations but higher ferritin and erythrocyte riboflavin concentrations. Weight at birth or at 1 mo of age was positively related to iron, zinc and vitamin A status, but a more rapid weight gain was associated with depletion of iron stores. Socioeconomic status was related to higher hemoglobin, riboflavin and zinc concentrations. The feeding of a micronutrient-fortified food was positively associated with plasma ferritin and retinol concentrations at 12 mo. These results suggest that prenatal factors, socioeconomic status, dietary intake and morbidity all influence infant micronutrient status, and that fortification of complementary foods is one potential avenue for preventing deficiencies.

Anthropometry↗
PubMed1999

Effects of discontinuing coffee intake on iron deficient Guatemalan toddlers' cognitive development and sleep.

Coffee is commonly given daily to toddlers in Guatemala. Possible negative effects of coffee ingestion on cognitive development and sleep patterns were assessed in 132 children 12-24 months of age who had received coffee for > 2 months and were iron deficient on at least one indicator. Children were stratified by initial hemoglobin (A= anemic, Hgb < 10.5 g/dl; NA = 'non-anemic', Hgb > or = 10.5 g/dl) and were randomly assigned to an experimental group (S = substitute consisting of sugar and coloring), and a control group (C = continuation of coffee) (42 C-NA; 53 S-NA; 18 C-A; and 19 S-A). Anemic children were provided Fe supplements for 2-3 months. Compliance was assessed every 2 weeks. After 5 months, testers masked to treatment group and anemia evaluated children with the Bayley Scales of Infant Development II in a central location. Scores were the Mental Development Index (MDI), the Psychomotor Development Index (PDI), and scales from the Behavior Rating Scale (BRS). The child's sleep in the previous 24 h was assessed with a set of standardized sleep questions to the care giver on the first visit and every 2 weeks thereafter. No significant effects of treatment on test scores or BRS ratings were found. In the 24 h period reported on at the final visit, children in the Substitute group slept more during the night and overall (night plus naps) than children in the Coffee group, a difference not found at the first visit. No differences were found in sleep difficulty or number of times waking at night. Women's reported coffee intake per day during pregnancy was associated with lower BRS ratings, even after controlling for SES and child age. The effects of postnatal coffee ingestion in Guatemala were seen for sleep duration, but not for cognitive development. Prenatal coffee ingestion was negatively associated with Behavior Rating Scales and should be investigated further.

Anemia, Iron-Deficiency↗
PubMed1999

The effects of fermentation and/or vacuum flask storage on the presence of coliforms in complementary foods prepared for Ghanaian children.

Microbial contamination of complementary foods is a major cause of childhood diarrhoea. In a community-based study in Ghana, we evaluated whether fermentation of maize porridge or storage of porridge in vacuum flasks reduces coliform contamination. The complementary food examined, Weanimix, consisted of, on a dry weight basis, toasted maize (75%), peanuts (10%), and soybeans (15%) milled into flour. The fermented food was Weanimix made with drum-dried, previously fermented maize. Fifty women with infants 6-18 months of age participated. A repeated measures cross-over design was used. Each mother participated in all four treatments (1 week per treatment, in random order): (a) non-fermented Weanimix (W), (b) fermented Weanimix (F), (c) non-fermented Weanimix stored in a vacuum flask (WV), and (d) fermented Weanimix stored in a vacuum flask (FV). Each week, mothers were supplied with the appropriate food, and asked to prepare a porridge each morning by boiling the dry mix in water. Samples were collected in the evenings and immediately plated onto 3 M Petrifilm. Contamination was defined as > or = 100 colony-forming units of coliforms per ml. Contamination rates (95% confidence intervals) were W = 48% (38-58%), F = 25% (17-34%), WV = 42% (32-52%), and FV = 13% (6-20%). All pairwise comparisons were significant (P < 0.05) except for W vs WV. Within the WV treatment, contamination rates were 85% when the sample temperature fell below 50 degrees C (N = 41) vs 12% when it remained > 50 degrees C (N = 59) (P < 0.001). These results indicate that contamination is reduced by fermentation, and further reduced by vacuum flask storage of fermented foods. For non-fermented foods, vacuum flask-storage was protective only when the temperature was maintained at > 50 degrees C; at < or = 50 degrees C vacuum flask storage increased the risk of contamination.

Cross-Over Studies↗
PubMed1999

Age of introduction of complementary foods and growth of term, low-birth-weight, breast-fed infants: a randomized intervention study in Honduras.

BACKGROUND: The optimal age at which to introduce complementary foods is a topic of considerable debate. OBJECTIVE: This study was designed to evaluate this issue in a nutritionally vulnerable population in Honduras. DESIGN: Mothers of low-birth-weight (1500-2500 g) term (ie, small-for-gestational-age) infants were recruited in the hospital and assisted with exclusive breast-feeding during the first 4 mo. At 4 mo, mothers were randomly assigned to either continue exclusive breast-feeding to 6 mo (EBF; n = 59) or to feed complementary solid foods (jarred rice cereal, chicken, and fruit and vegetables) twice daily from 4 to 6 mo while continuing to breast-feed at their initial frequency (SF; n = 60). At 4 and 6 mo, breast milk and total energy intake were measured for a nonrandom subsample (those who could stay overnight in a central unit: 32 EBF and 31 SF). RESULTS: At 4 mo, breast milk intake in the subsample was not significantly different between groups (EBF: 729 +/- 135 g/d; SF: 683 +/- 151 g/d: P >0.2); from 4 to 6 mo it increased (by 28 g/d) in the EBF group but decreased (by 39 g/d) in the SF group (P < 0.005). Nonetheless, total energy intake (including solid foods) increased more from 4 to 6 mo in the SF than in the EBF group. However, there were no significant differences between groups in weight or length gain during the intervention or subsequently (6-12 mo). CONCLUSION: There was no growth advantage of complementary feeding of small-for-gestational-age, breast-fed infants between 4 and 6 mo of age.

Adult↗
PubMed1999

Randomized trial of the short-term effects of dieting compared with dieting plus aerobic exercise on lactation performance.

BACKGROUND: Limiting postpartum weight retention is important for preventing adult obesity, but the effect of weight loss on lactation has not been studied adequately. OBJECTIVE: We evaluated whether weight loss by dieting, with or without aerobic exercise, adversely affects lactation performance. DESIGN: At 12+/-4 wk postpartum, exclusively breast-feeding women were randomly assigned for 11 d to a diet group (35% energy deficit; n = 22), a diet plus exercise group (35% net energy deficit; n = 22), or a control group (n = 23). Milk volume, composition, and energy output; maternal weight, body composition, and plasma prolactin concentration; and infant weight were measured before and after the intervention. RESULTS: Weight loss averaged 1.9, 1.6, and 0.2 kg in the diet, diet + exercise, and control groups, respectively (P < 0.0001) and was composed of 67% fat in the diet group and nearly 100% fat in the diet + exercise group. Change in milk volume, composition, and energy output and infant weight did not differ significantly among groups. However, there was a significant interaction between group and baseline percentage body fat: in the diet group only, milk energy output increased in fatter women and decreased in leaner women. The plasma prolactin concentration was higher in the diet and diet + exercise groups than in the control group. CONCLUSIONS: Short-term weight loss (approximately 1 kg/wk) through a combination of dieting and aerobic exercise appears safe for breast-feeding mothers and is preferable to weight loss achieved primarily by dieting because the latter reduces maternal lean body mass. Longer-term studies are needed to confirm these findings.

Adult↗
PubMed1999

Precision, accuracy, and reliability of hemoglobin assessment with use of capillary blood.

BACKGROUND: Previous research has suggested that there may be significant within-subject variability, both site-to-site and over time, in hemoglobin concentrations in capillary blood. OBJECTIVE: This study examined the reliability of the portable hemoglobinometer (PHM) system with use of capillary blood and the implications of errors of the magnitude found for the classification of anemia status in individuals and population groups. The precision and accuracy of the method with use of venous blood were also tested. DESIGN: Three empirical data sets were used to measure reliability, precision, and accuracy of the PHM system [2 from Honduras (n = 87 and 141); 1 from Bangladesh (n = 73)]. Simulation data were used to assess the implications of errors for screening individuals for anemia and to estimate anemia prevalence. RESULTS: High within-subject variability (unreliability) was identified when capillary blood from the left hand was compared with that from the right hand (CV: 6.3%) and when measurements were taken on 4 consecutive days (CV: 7.0%). Reliability was only 69% and 50%, respectively. Precision and accuracy, however, were very high (concordance coefficients of 0.99 and 0.98 and CV < 1%). CONCLUSIONS: The simulation data showed that errors of the magnitude found due to unreliability can lead to misclassification of anemia status in individuals and small biases in anemia prevalence estimates. We recommend replicate sampling to reduce the influence of unreliability in the use of the PHM system with capillary blood.

Adolescent↗
PubMed1999

A randomized, community-based trial of the effects of improved, centrally processed complementary foods on growth and micronutrient status of Ghanaian infants from 6 to 12 mo of age.

BACKGROUND: Koko, a fermented maize porridge used as the primary complementary food in Ghana, has been implicated in the high prevalence of child malnutrition. Weanimix, a cereal-legume blend developed by the United Nations Children's Fund and the Ghanaian government, has been promoted as an alternative. OBJECTIVE: We evaluated the effect of feeding Weanimix and 3 other locally formulated, centrally processed complementary foods on the nutritional status of 208 breast-fed infants. DESIGN: Infants were randomly assigned to receive 1 of 4 foods from 6 to 12 mo of age: Weanimix (W), Weanimix plus vitamins and minerals (WM), Weanimix plus fish powder (WF), and koko plus fish powder (KF). Dietary and anthropometric data were collected regularly. Blood was collected at 6 and 12 mo of age to assess iron, zinc, vitamin A, and riboflavin status. Before and after the intervention, cross-sectional data on the anthropometric status of infants not included in the intervention (NI; n = 464) were collected. RESULTS: There were no significant differences between intervention groups in weight or length gain or in hemoglobin, hematocrit, transferrin saturation, plasma zinc, or erythrocyte riboflavin values between 6 and 12 mo of age. From 9 to 12 mo of age, z scores were lower in NI infants than in the combined intervention groups [at 12 mo: -1.71 +/- 0.90 compared with -1.19 +/- 0.93 for weight and -1.27 +/- 1.02 compared with -0.63 +/- 0.84 for length (P < 0.001 for both), respectively]. The percentage of infants with low ferritin values increased significantly between 6 and 12 mo of age in groups W, WF, and KF but not in group WM. Change in plasma retinol between 6 and 12 mo of age was significantly greater in group WM than in the other 3 groups combined (0.14 +/- 0.3 compared with -0.04 +/- 0.3 micromol/L, P = 0. 003). CONCLUSIONS: All 4 foods improved growth relative to the NI group. Infants fed WM had better iron stores and vitamin A status than those fed nonfortified foods.

Adult↗