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Biomedical subjects

E Pollitt

Publications and source records attributed to E Pollitt.

At least 55 records · Page 3Linked to original sources

Outcome of maternal nutritional supplementation: a comprehensive review of the Bacon Chow study.

In a double blind controlled intervention, two groups of nutritionally at-risk rural Taiwanese women were given a nutrient-rich dietary supplement (group A, n = 114) or a placebo (group B, n = 111) beginning after the birth of one child and continuing through the lactation period for a subsequent child. Outcome variables assessed include infant birth measurements postnatal physical growth, motor, mental, and dental development, morbidity, and maternal weight and skinfold changes during pregnancy and lactation. While few A-B differences in mean values of outcome variables were found, there were significant responses in subgroups of the sample. Comparisons of infants born after a nutrient-supplemented pregnancy (A2) versus an unsupplemented pregnancy (A1) showed that A2 male infants weighed more than A1 males at birth, and A1-A2 sibling correlations in birth measurements, especially Rohrer's index (wt/l3) were significantly reduced. Important mediators of supplement effects included sex of the offspring, season of birth, maternal body size, and birth of a previous infant characterized by dysmorphic prenatal growth. The limited effects of supplementation on the population as a whole may reflect the operation of long term adaptations which allow women to maintain reproductive success despite their apparent marginal nutritional status.

Adult

Iron deficiency anemia and educational achievement.

The present study investigates the effect of iron supplementation on measures of school performance among 78 iron-deficient anemic and 41 nonanemic children in an economically deprived rural area in Central Java, Indonesia. All the subjects were treated for ancylostomiasis before iron supplementation. They were randomly assigned to either an iron or placebo group. Hematological and behavioral measurements were obtained immediately before (T1) and after (T2) the iron and placebo treatments. Iron treatment for a 3-mo period resulted in substantive increases in mean Hgb, Hct, and transferrin saturation among the iron-deficient anemic children. Furthermore, changes in the iron status of iron-deficient anemic children were associated with significant changes in the school achievement test scores of iron-deficient anemic children. T2 evaluation of achievement test scores indicated that the difference between iron-treated anemic and nonanemic children was still statistically significant. However, when T1 scores were entered as a covariate, iron-deficient anemic subjects treated with iron obtained significantly higher delta achievement scores. Findings from the present study indicate that iron supplementation among iron-deficient anemic children benefits learning processes as measured by the school achievement test scores.

Ancylostomiasis

The bacon Chow study: effects of maternal nutritional supplementation on birth measurements of children, accounting for the size of a previous (unsupplemented) child.

Studies on nutritional supplementation of pregnant mothers have observed small but sometimes significant effects on fetal growth. Previously we also reported significant changes in physical resemblance of siblings at birth due to this kind of supplementation, using data collected by the late Dr. Bacon Chow and associates. This suggested that components of variation in physical growth may change as a result of supplementation. To explore this further, we sought the effects of nutritional supplementation on somatic growth, holding constant the birth measurements of a previous (unsupplemented) sibling. Only head circumference at birth came close to showing a statistically significant (P less than 0.06) supplement effect on its mean (+ 0.36 cm) when the measurement of the first infant was held constant. Both increases and decreases in weight for length as assessed by Rohrer's Index (wt/l3) occurred with supplementation. Increases in the index occurred by a significant (P less than 0.01) gain in birth weight (238 g) between 1st and 2nd siblings in the supplement group but not in the placebo group. Decreases in this index resulted from a significant gain in birth length (1.3 cm) in supplemented families with a previous (untreated) sibling having a below average length for average weight. These non-linear effects on somatic growth suggest that responses to maternal nutritional supplementation may be more effective in a subgroup of the population where the normal adaptive responses to low energy protein intakes may have failed or where nutritional conditions over pregnancy may have varied considerably.

Biometry

The Bacon Chow study: effect of nutritional supplementation on maternal weight and skinfold thicknesses during pregnancy and lactation.

Effects of a feeding programme on maternal weight, triceps and subscapular skinfolds during pregnancy and lactation were assessed in a marginally undernourished population of rural Taiwan. Mothers participated during two pregnancy and lactation periods. At 3 weeks after the delivery of the first infant, one group of 114 mothers began consuming a nutrient-dense supplement (A), while another group of 111 received a placebo (B). There was no significant A-B difference in pregnancy weight gain (A 7.52 kg, B 7.75 kg) or in mean maternal weight, triceps or subscapular skinfolds at any time during pregnancy or lactation. Despite a general trend toward moderate weight loss during lactation, one-third of mothers in both groups gained weight. Highly significant increases in weight and skinfold thicknesses from one lactation period to the next characterized both groups. The absence of demonstrable supplement-effects on maternal anthropometry concomitant with increments in infant birth weight supports the notion that infants can benefit from maternal supplementation without changes in maternal nutritional status.

Adult

Application of receiver-operator analysis to diagnostic tests of iron deficiency in man.

The objective of the present report is to demonstrate the use of receiver-operator characteristics (ROC) analysis in the selection of diagnostic tests for iron deficiency in a specific population. Conventional ROC curves were prepared with true positive fraction (TPF) and false positive fraction (FPF) determined by the application of different cut-off points for four indicators of iron status. ROC plots were then transformed into normal deviate scales. The advantages of Gaussian transformation of TPF and FPF when underlying decision functions are normally distributed are: the ROC curve is a straight line; and the separation between the two distributions and shape of these distributions can be simply quantitated as intercepts and slopes. In the present study, pretreatment hemoglobin concentration was the most robust diagnostic indicator of iron deficiency as operationally defined by a response of hemoglobin to iron treatment. Free erythrocyte protoporphyrin was a more sensitive and specific predictor than either serum ferritin or transferin saturation when a stringent operational definition of iron deficiency was used. These findings illustrate the utility of ROC analysis in discriminating between diagnostic indicators having different degrees of accuracy.

Anemia, Hypochromic

Seasonal variation in pre- and postpartum maternal body measurements and infant birth weights.

A sample of 225 rural Taiwanese women were followed longitudinally through two successive pregnancy and lactation periods. Maternal pre- and postpartum weight and skinfold thicknesses and infant birth weights showed considerable seasonal variation. The lowest mean maternal weights, irrespective of pregnancy or lactation status, occurred in the summer months of June, July, and August, when temperatures and rainfall reach their yearly maxima. The lowest mean birth weights were also recorded for the warm, rainy summer months. Furthermore, a disproportionate number of infants weighing less than one standard deviation below the mean birth weight were born between May and October. The observed seasonal variations most probably reflect annual cycles of agricultural activities and food availability.

Adult

The Bacon Chow study: maternal supplementation and infant growth.

The effect of maternal supplementation during both gestation and lactation on infant growth from birth to 12 mth was investigated in the double-blind, randomly allocated control trial conducted in Taiwan by the late Bacon F. Chow. The supplement was a milk-based formula providing 800 kcal and 40 g protein daily. The placebo provided less than 40 kcal per diem but resembled the supplement in appearance. Supplementation was limited to mothers and began after birth of one infant and continued without interruption until weaning of a second infant. Supplement effects were tested by comparing both supplement and placebo groups and first- and second-infant groups with respect to weight, length and head circumference. Both comparisons of growth curves and analyses of variance were carried out. Both strategies agreed in failing to detect differences in growth between supplement and placebo groups. However, differences were found between first and second infants in the supplement group.

Adult

The Bacon Chow study: maternal nutritional supplementation and infant behavioral development.

The effect of maternal nutritional supplementation during pregnancy and lactation on the mental and motor development of infants was studied in a rural population in Taiwan. Women were randomly assigned to 2 treatment groups: 1 received a high-calorie and protein supplement ("supplement" group); the other received a placebo ("control" group). Infants received no direct supplementation. At approximately 8 months of age, the mental and motor development of the infants was assessed using a research to maternal supplementation in either scale, nor were the mental scale scores of infants of supplement mothers significantly higher than infants of control mothers. However, the motor scores of supplement infants were higher than those of control infants, which is consistent with the findings of 2 other large-scale nutritional supplementation studies.

Adult

Maternal nutrition supplementation during pregnancy interferes with physical resemblance of siblings at birth according to infant sex.

A randomized controlled double-blind study of nutrition supplementation of pregnant and lactating women was conducted in Suilin township, Taiwan. Pregnant mothers were randomly assigned to one of two treatment groups consisting of either a high (800 kcal and 40 g protein) calorie daily supplement or a placebo. For each mother treatment began following the delivery of her first study infant, continued throughout the lactation period; and through the pregnancy and lactation of her second study infant. Comparisons of sibling-sibling anthropometric correlations at birth between groups show that among the placebo group the sibling correlations are statistically significant and of the same magnitude seen in previous studies (approximately 0.5), while among high calorie siblings correlations are unusually low and often not significant. This is particularly true for male fetuses, suggesting that the latter are more sensitive to nutritional environmental variations in utero, than are female fetuses. Reduction in familial correlations, presumed measures of genetic influence, in nutritionally stressed populations, will occur when the environment of relatives differ, but are not due to malnutrition per se.

Adult