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Biomedical subjects

B Lozoff

Publications and source records attributed to B Lozoff.

At least 19 recordsLinked to original sources
PubMed2002

Spontaneous motor activity in human infants with iron-deficiency anemia.

This study compared spontaneous motor activity in 6-month-old Chilean infants with or without iron-deficiency anemia (IDA) who were otherwise healthy. Activity was assessed in conjunction with polysomnographic recording during an afternoon nap in 11 infants with IDA and 15 with normal hemoglobin levels. All infants were given oral iron, and activity was reassessed at 12 and 18 months. Using actigraphs placed on the ankle, the frequency of movement units per minute was determined for each waking/sleep state. The total amount of time infants were in an alert-active state before and after the nap was used to calculate the proportion of movements/minute of waking. There were no differences between anemic and nonanemic infants in total recording time, duration of sleep, or motor activity during sleep. However, infants with IDA showed reduced motor activity during waking at all ages. The magnitude of the differences increased at 12 and 18 months. Thus, IDA was associated with reduced motor activity in infants even after iron treatment. It will be important to confirm these results in a larger sample and to determine the 24-h pattern of motor activity, since reduced motor activity may limit infants' opportunities to explore and learn from the social and physical environment.

Anemia, Iron-Deficiency↗
PubMed2002

Twenty-four-hour motor activity in human infants with and without iron deficiency anemia.

Iron deficiency anemia (IDA) is a very common nutritional problem that alters motor activity. The aim of this study was to compare 24-h motor activity in the home in healthy 6-month-old infants with and without IDA. Activity was assessed via actigraphs on the leg during 24 continuous hours in 17 Chilean infants with IDA and 18 with normal hemoglobin levels. All infants were given oral iron, and activity was reassessed at 12 and 18 months. The frequency of movement units per minute was determined for each waking/sleep state during the day and night, and the duration of each state was computed. At 6 months of age, there were no differences between anemic and nonanemic infants in time per state. However, infants with IDA showed an overall increase in motor activity compared to controls. These differences were no longer observed at 12 and 18 months of age. Increased activity during the period of IDA raises the issue of a shared underlying mechanism with restless legs syndrome, a sensorimotor dysfunction where iron deficiency increases the severity of the symptoms and iron supplementation ameliorates them. Due to previous findings of decreased motor activity in the laboratory at 12 months during the waking time surrounding an afternoon nap, we also compared those data to a nap in the home. Infants with IDA were less active in the laboratory than in the home. The home versus laboratory results suggest that contextual factors affect the motor activity of IDA infants to a larger extent than controls.

Anemia, Iron-Deficiency↗
PubMed2000

Poorer behavioral and developmental outcome more than 10 years after treatment for iron deficiency in infancy.

OBJECTIVE: To determine the long-term effects of iron deficiency in infancy. DESIGN: Longitudinal follow-up study of children who had been tested and treated for iron deficiency as infants. SETTING: Periurban community near San Jose, Costa Rica. PARTICIPANTS: Of the original 191 participants, 87% were reevaluated at 11 to 14 years old (average age: 12.3 years). The children were free of iron deficiency and growing normally by US standards. Those who had chronic, severe iron deficiency in infancy (n = 48) were compared with those who had good iron status before and/or after iron therapy in infancy (n = 114). OUTCOME MEASURES: Comprehensive set of cognitive, socioemotional, and motor tests and measures of school functioning. RESULTS: Children who had severe, chronic iron deficiency in infancy scored lower on measures of mental and motor functioning. After control for background factors, differences remained statistically significant in arithmetic achievement and written expression, motor functioning, and some specific cognitive processes (spatial memory, selective recall, and tachistoscopic threshold). More of the formerly iron-deficient children had repeated a grade and/or been referred for special services or tutoring. Their parents and teachers rated their behavior as more problematic in several areas, agreeing in increased concerns about anxiety/depression, social problems, and attention problems. CONCLUSIONS: Severe, chronic iron deficiency in infancy identifies children who continue at developmental and behavioral risk >10 years after iron treatment.

Adolescent↗
PubMed1999

Cosleeping in context: sleep practices and problems in young children in Japan and the United States.

OBJECTIVE: To determine the relationship between cosleeping and sleep problems in cultures with very different sleep practices. DESIGN: Interview study. SETTING: Families in urban Japan and the United States identified through pediatric and other professional contacts. PARTICIPANTS: Parents of healthy 6- to 48-month-old children (56 Japanese parents and 61 white US parents). All children had been breast-fed and lived in 2-parent, middleclass households. INTERVENTION: None. MAIN OUTCOME MEASURE: Sleep practices and sleep problems. RESULTS: More Japanese than US children coslept 3 or more times per week (59% vs. 15%, P<.001). All cosleeping Japanese children regularly slept all night with their parents (vs. 11% of US cosleepers, P<.001). Japanese and US children did not differ in part-night cosleeping (7% vs. 13%, P = .37). Most Japanese children had adult company and body contact as they fell asleep, and fathers slept separately in 23% of families. A greater proportion of US children had regular bedtime struggles and night waking. Within the US sample, cosleeping was associated with more bedtime struggles (P<.001), night waking (P<.01), and overall stressful sleep problems (P<.01). In the Japanese sample, cosleeping was associated only with night waking (P<.05); however, the proportion of cosleeping Japanese children with frequent night waking was at the level reported for US children who slept alone (30% vs 23%, P = .47). CONCLUSIONS: Cultural differences seem to influence the relationship between sleep practices and sleep problems. The experience of the Japanese families indicates that cosleeping per se is not associated with increased sleep problems in early childhood.

Adult↗
PubMed1998

Prevention of iron-deficiency anemia: comparison of high- and low-iron formulas in term healthy infants after six months of life.

OBJECTIVES: For bottle-fed babies or nursing infants who receive milk supplements, the American Academy of Pediatrics recommends the use of iron-fortified infant formula. Because these recommendations have not been universally adopted, the hematologic effects of currently available low-iron formulas need to be determined. STUDY DESIGN: Healthy Chilean 6-month-old infants (without iron-deficiency anemia, born at term weighing > or 3.0 kg) who were totally or partially weaned from the breast were randomly allocated in a double-blind fashion to receive high-iron (n = 430) or low-iron formula (n = 405), containing an average of 12.7 mg/L or 2.3 mg/L, respectively, of elemental iron as ferrous sulfate. Iron status was determined at 12 months. RESULTS: The prevalence of iron-deficiency anemia was not different in the high- and low-iron groups (2.8% versus 3.8%, p = 0.35). Nevertheless, infants receiving high-iron formula had somewhat higher levels of hemoglobin and serum ferritin, greater mean cell volumes, and lower erythrocyte protoporphyrin levels (p < 0.005). CONCLUSIONS: Although high-iron formulas are more efficacious in improving iron status, currently available low-iron formulas may prevent iron-deficiency anemia in selected healthy, term infant populations with otherwise poor sources of dietary iron after 6 months of life. Formulas with relatively small amounts of iron appear to prevent iron-deficiency anemia. We speculate that the optimal level of iron fortification likely lies somewhere between the current levels in high- and low-iron formulas.

Anemia, Iron-Deficiency↗
PubMed1998

Evidence of altered central nervous system development in infants with iron deficiency anemia at 6 mo: delayed maturation of auditory brainstem responses.

Iron deficiency anemia has long been thought to have effects on the central nervous system (CNS). Finding direct evidence of this in human infants, however, has been challenging. Auditory brainstem responses (ABRs) provide a noninvasive means of examining an aspect of the CNS that is rapidly maturing during the age period when iron deficiency is most common. ABRs represent the progressive activation of the auditory pathway from the acoustic nerve (wave I) to the lateral lemniscus (wave V). The central conduction time (CCT, or wave I-V interpeak latency) is considered an index of CNS development because myelination of nerve fibers and maturation of synaptic relays lead to an exponential reduction in the CCT from birth to 24 mo. In 55 otherwise healthy, 6-mo-old Chilean infants (29 with iron deficiency anemia and 26 nonanemic control infants), the CCT was longer in those who had been anemic at 6 mo, with differences becoming more pronounced at 12- and 18-mo follow-ups despite effective iron therapy. The pattern of results--differences in latencies but not amplitudes, more effects on the late ABR components (waves III and V), and longer CCTs (as an overall measure of nerve conduction velocity)--suggested altered myelination as a promising explanation, consistent with recent laboratory work documenting iron's essential role in myelin formation and maintenance. This study shows that iron deficiency anemia in 6-mo-old infants is associated with adverse effects on at least one aspect of CNS development and suggests the fruitfulness of studying other processes that are rapidly myelinating during the first 2 y of life.

Anemia, Iron-Deficiency↗
PubMed1998

Behavior of infants with iron-deficiency anemia.

This study tested the hypothesis that infants with iron-deficiency anemia show behaviors, such as increased proximity to caregivers, increased wariness or hesitance, and decreased activity, that could contribute to "functional isolation." The behavior of 52 Costa Rican 12- to 23-month-old infants with iron-deficiency anemia was contrasted with that of 139 comparison group infants with better iron status during free play and mental and motor testing and in the home. Infants with iron-deficiency anemia maintained closer contact with caregivers; showed less pleasure and delight; were more wary, hesitant, and easily tired; made fewer attempts at test items; were less attentive to instructions and demonstrations; and were less playful. Adult behavior also differed. The results indicate that iron-deficiency anemia in infancy is associated with alterations in affect and activity, suggesting that functional isolation is a useful framework for understanding poorer developmental outcome in iron-deficiency anemia, the world's most common single nutrient deficiency.

Affect↗
PubMed1996

Iron-deficiency anemia and infant development: effects of extended oral iron therapy.

OBJECTIVE: To determine whether extended oral iron therapy corrects lower developmental test scores in infants with iron-deficiency anemia. STUDY DESIGN: Double-blind, controlled trial in Costa Rica involving 32 12- to 23-month-old infants with iron-deficiency anemia and 54 nonanemic control subjects. Anemic infants were treated with orally administered iron for 6 months; half the nonanemic children were treated with iron and half with placebo. Developmental test scores and hematologic status were evaluated before treatment, after 3 months, and after 6 months. RESULTS: Iron-deficient anemic infants received lower mental test scores than nonanemic infants at all three time points (p < 0.05 pretreatment and at 3 months, p = 0.07 at 6 months). There were no significant differences in motor test scores. More of the anemic infants were rated as unusually tearful and unhappy. Anemic infants came from families with lower maternal education and less support for child development and were less likely to be breast fed, were weaned earlier, and consumed more cow milk. CONCLUSIONS: Lower mental test scores persisted in infants with iron-deficiency anemia despite extended oral iron therapy and an excellent hematologic response. Iron-deficiency anemia may serve as a marker for a variety of nutritional and family disadvantages that may adversely affect infant development.

Administration, Oral↗
PubMed1996

Brain iron and behavior of rats are not normalized by treatment of iron deficiency anemia during early development.

Previous studies in rats have shown that iron deficiency anemia (IDA) during brain development results in lower brain iron concentration and behavioral deficits that persist despite iron treatment after weaning. The present study used a developmental IDA model to determine whether earlier iron treatment might normalize brain iron concentration and behavior. One and one-half week periods of IDA were instituted during early or late gestation or lactation by providing low iron diet to adolescent rat dams and oral iron treatment at the end of the anemia period. The iron deficiency anemia of dams during gestation and lactation resulted in significantly lower pup brain iron concentration at 3 mo of age (15-33% lower than control), despite iron treatment of dams as early as mid-gestation. Dam IDA during lactation lowered pup brain iron concentration significantly more than IDA during gestation (21% lower). All IDA groups had significantly poorer performance and lower activity compared with controls on a screen of home orientation at 8 d of age. Activity on this test was significantly less than controls at 12 d of age. Homing ability on d 12 and 16 and activity on d 16 did not differ from controls. Groups that were anemic around delivery had significant behavioral differences at 3 mo which included less defecation in the open field and greater swim distance in the Morris maze. These results raise the concern that iron sufficiency throughout the course of rain development is crucial to the achievement of normal brain iron concentration and behavior in rats.

Administration, Oral↗
PubMed1996

Cosleeping and early childhood sleep problems: effects of ethnicity and socioeconomic status.

This study examined ethnic differences in the relationship between cosleeping and sleep problems in the United States, taking socioeconomic status (SES) into consideration. The sample consisted of 186 urban families with a healthy 6- to- 48-month-old child and was grouped as follows: white lower SES (n = 40), white higher SES (n = 54), black lower SES (n = 43), and black higher SES (n = 47). Regular cosleeping was associated with increased night waking and/or bedtime protests among lower SES white children and higher SES black children. Among families who coslept, white parents were more likely than black parents to consider their child's sleep behavior to be a problem, i.e., stressful, conflictual, or upsetting as well as regularly occurring. One explanation is that differing childrearing attitudes and expectations influenced how parents interpreted their children's sleep behavior.

Black or African American↗
PubMed1995

Serum prolactin levels and behavior in infants.

This study examined the relationship between serum prolactin levels and behavior in infants and toddlers who experienced two potentially stressful experiences (developmental testing and venipuncture). Serum prolactin levels showed considerable consistency over a 3-month period (r = 0.64 between study entry and three months, p < 0.001, n = 50). There was also stability in having either a normal or a high value (> or = 25 ng/ml). Among children who had a normal value on initial testing, 97% also has a normal value after 3 months; 55% of those with initial high values continued to have high values (chi 2 = 19.26, p < 0.001). Children with high serum prolactin levels were more likely to be rated as unusually hesitant and unhappy during developmental testing. Overall, 53% of the children with serum prolactin levels > or = 25 ng/ml were considered abnormal in affect, compared to 20% of those with lower serum prolactin values (total n = 138, chi 2 = 13.56, p < 0.001). These results suggest that, even in early life, serum prolactin levels may reflect characteristic individual behavioral and neuroendocrine responses to stress.

Female↗
PubMed1994

No evidence of developmental III effects of low-level lead exposure in a developing country.

Despite substantial controversy regarding the blood levels at which lead adversely affects neurobehavioral development, public health policy in some industrialized countries is prescribing ever more stringent screening criteria for all ages. This study addressed the question of ill effects of lead exposure at the new lower levels, specifically during the late infancy period, which has been targeted for maximum surveillance in pediatric practice. The sample of 184 participants consisted of 12- to 23-month-old healthy infants and toddlers who participated in a community-based study in a developing Central American country (Costa Rica) where extensive family and developmental information was collected. The mean infant blood lead level was 11.0 micrograms/dL, ranging from 5.4 to 37.0 micrograms/dL. Lead levels were not related to the Mental or Psychomotor Developmental Index of the Bayley Scales of Infant Development. When the children were 5 years old, they were reevaluated with complete physical and psychological testing. Blood lead levels in infancy did not predict any of the developmental outcome measures. Thus, among a group of healthy toddlers in a developing country, no ill effects on development of low blood lead levels were observed.

Anemia, Iron-Deficiency↗
PubMed1991

Long-term developmental outcome of infants with iron deficiency.

BACKGROUND: Iron-deficiency anemia has been associated with lowered scores on tests of mental and motor development in infancy. However, the long-term developmental outcome of infants with iron deficiency is unknown, because developmental tests in infancy do not predict later intellectual functioning. METHODS: This study is a follow-up evaluation of a group of Costa Rican children whose iron status and treatment were documented in infancy. Eighty-five percent (163) of the 191 children in the original group underwent comprehensive clinical, nutritional, and psychoeducational assessments at five years of age. The developmental test battery consisted of the Wechsler Preschool and Primary Scale of Intelligence, the Spanish version of the Woodcock-Johnson Psycho-Educational Battery, the Beery Developmental Test of Visual-Motor Integration, the Goodenough-Harris Draw-a-Man Test, and the Bruininks-Oseretsky Test of Motor Proficiency. RESULTS: All the children had excellent hematologic status and growth at five years of age. However, children who had moderately severe iron-deficiency anemia as infants, with hemoglobin levels less than or equal to 100 g per liter, had lower scores on tests of mental and motor functioning at school entry than the rest of the children. Although these children also came from less socioeconomically advantaged homes, their test scores remained significantly lower than those of the other children after we controlled for a comprehensive set of background factors. For example, the mean (+/- SD) adjusted Woodcock-Johnson preschool cluster score for the children who had moderate anemia in infancy (n = 30) was 448.6 +/- 9.7, as compared with 452.9 +/- 9.2 for the rest of the children (n = 133) (P less than 0.01); the adjusted visual-motor integration score was 5.9 +/- 2.1, as compared with 6.7 +/- 2.3 (P less than 0.05). CONCLUSIONS: Children who have iron-deficiency anemia in infancy are at risk for long-lasting developmental disadvantage as compared with their peers with better iron status.

Anemia, Hypochromic↗
PubMed1991

Early genital naming.

To evaluate the clinical impression that young girls are given little or confusing information about their genitals, a sample of 117 mothers with 1- to 4-year-old children were asked which words for genitals, if any, they used with their children. The ethnically and socioeconomically heterogeneous sample was composed of 63 girls and 54 boys, with the average ages of 26 and 29 months, respectively. Neither boys nor girls were likely to be given a standard anatomical genital term, although many children received colorful colloquial expressions. However, girls were less likely than boys to receive a term for their genitals. Receiving names for genitals was related to certain family circumstances, such as higher parental education, exposure to adult male nudity, having a sibling of the opposite sex, and cosleeping. Pediatric health professionals have the opportunity to contribute to early sex education by conveying accurate information regarding genital terms in the course of routine physical examinations.

Child Language↗