Robert S. Byrd

The effects of tobacco exposure on children's behavioral and cognitive functioning: - Implications for clinical and public health policy and future research

A growing body of literature indicates that maternal smoking during pregnancy is associated with neurotoxic effects on children. Both animal model studies and human epidemiologic studies demonstrate similar effects in terms of increased activity, decreased attention, and diminished intellectual abilities. Epidemiologic studies also suggest that prenatal tobacco exposure is associated with higher rates of behavior problems and school failure. These findings are explored and their implications for child health policy and practice, and for research, are discussed.

The onset of autism: patterns of symptom emergence in the first years of life

Previous conceptualizations of autism have suggested that symptoms are evident either early in the first year of life or later in the second year, after a loss of previously acquired skills. New research suggests, however, that these two patterns do not capture all the different ways autism can emerge. For example, some children show a developmental plateau marked by failure to progress, while other children display mixed features, with both early delays and later losses evident. This article reviews the literature on autism onset, discusses problems with the traditional ways in which onset has been conceptualized, and provides recommendations for future research. We suggest that onset is better thought of as a dimensional process rather than dichotomous categories.

Development and Validation of the Rapid Estimate of Adolescent Literacy in Medicine (REALM-Teen): A Tool to Screen Adolescents for Below-Grade Reading in Health Care Settings

OBJECTIVE. The magnitude and consequences of low literacy in adolescent health and health care are unknown. The purpose of this study was to validate the Rapid Estimate of Adolescent Literacy in Medicine (REALM-Teen), a word-recognition test in English that can be used as a brief literacy-screening tool in health care settings. PATIENTS AND METHODS. A total of 1533 adolescents aged 10 to 19 years attending 1 of 5 middle schools, 3 high schools, 1 pediatric clinic, or 2 summer programs in Louisiana and North Carolina participated in face-to-face interviews. Demographic information was solicited, and participants were administered a battery of reading tests, including the REALM-Teen, Wide Range Achievement Test–Revised (WRAT-3), and Slosson Oral Reading Test–Revised (SORT-R). Internal consistency for the REALM-Teen was determined using Cronbach’s α, and criterion validity was established through correlations with both the WRAT-R and SORT-R. Using reading below grade level (according to SORT-R scores) as an outcome, instrument accuracy and corresponding cutoff scores were calculated by plotting receiver operating characteristic curves and stratum-specific likelihood ratios. RESULTS. Participants were 50% black and 53% female; 34% were enrolled in middle school and 66% in high school. The average time required to administer the REALM-Teen was 3 minutes. Internal consistency was excellent, as was test-retest reliability. The REALM-Teen is strongly correlated with both the WRAT-R and SORT-R. Five reading level categories were identified: 3rd grade and below, 4th to 5th grade, 6th to 7th grade, 8th to 9th grade, and 10th grade and above. Forty-six percent of participants were reading below grade level according to the SORT-R and 28% had repeated at least 1 grade. CONCLUSION. The REALM-Teen is a brief, reliable instrument for assessing adolescent literacy skills and reading below grade level.

Vitamin and Mineral Supplement Use by Children and Adolescents in the 1999-2004 National Health and Nutrition Examination Survey Relationship With Nutrition, Food Security, Physical Activity, and Health Care Access

OBJECTIVE To determine if vitamin and mineral supplement use among children and adolescents in the United States is associated with nutrition, food security, physical activity, and health care access. DESIGN Secondary analysis of nationally representative data from the 1999-2004 National Health and Nutrition Examination Survey. SETTING Questionnaires, household interviews, and medical examinations. PARTICIPANTS Children and adolescents 2 to 17 years of age (N = 10 828). MAIN EXPOSURE Vitamin and mineral supplement use in the past month. MAIN OUTCOME MEASURES Demographics, nutrition, food security, physical activity, and health care access. RESULTS Approximately 34% (SE 1.2) used vitamin and mineral supplements in the past month, with underweight subjects reporting greater intake. Younger age, non-Hispanic white race/ethnicity, being born in the United States, higher milk intake, lower total fat and cholesterol intake, higher dietary fiber intake, higher income, greater food security, lower media/computer use, greater physical activity, lower body mass index, health insurance coverage, better health care access, and better self-reported health were associated with greater use of vitamin and mineral supplements. Such supplements contributed significantly to total daily dietary intakes of vitamins and minerals. CONCLUSIONS A large number of US children and adolescents use vitamin and mineral supplements, which for most may not be medically indicated. Such supplements contribute significantly to total dietary intakes of vitamins and minerals, and studies of nutrition should include their assessment. Since vitamin and mineral supplement users report greater health care access, health care providers may be in a position to provide screening and counseling regarding dietary adequacy and indications for supplement use.

Adherence to AAP Guidelines for Well-Child Care Under Managed Care

Objectives. To determine adherence to American Academy of Pediatrics (AAP) Recommendations for Preventive Pediatric Health Care in Monroe County, New York by individual patients and individual pediatricians under managed care practice and to compare adherence-to-recommendations rates for privately insured and publicly funded managed care patients. Study Designs and Methods. Using claims data for children 0 through 18 years of age cared for by pediatricians, we compared adherence to well-child care (WCC) visit recommendations for 130 572 children enrolled in a privately insured managed care system during 1992, 1993, and 1994 to 17 586 children insured by a publicly funded, Medicaid-managed care system during 1994 and 1995. Criteria for WCC visit adherence were based on 1991 AAP guidelines of 19 office visits from birth through 18 years of age. Adherence-to-recommendations rates by individual pediatricians also were determined. Results. Despite complete financial coverage of WCC visits (with no co-payment or deductible charges) by both insurance systems, strict adherence to AAP guidelines for WCC visits was low. Only 46% of privately insured and 35% of publicly funded children received all the recommended visits during the study period. During the same period, 17% of privately insured and 35% of publicly funded managed care patients received no WCC. There was little difference in the rate of full WCC visit adherence by age in either system with the rates ranging in privately insured patients from 49% in infants (<2 years of age) to 47% in adolescents (12 through 18 years of age) and ranging in publicly funded patients from 36% to 34% in these two age groups, respectively. Only 2% of privately insured infants had no record of WCC compared with 29% of adolescents. This contrasted with 12% of infants and 54% of adolescents who were publicly funded. Of pediatricians, <5% achieved 100% adherence to AAP guidelines for their patients (privately insured or publicly funded). Pediatricians completed an average of 52% of the recommended visits with their publicly funded patients and 68% of the recommended visits with their privately insured patients. Conclusions. WCC visits were underutilized for children in both managed care systems. Children of parents who have low incomes presumably could benefit greatest by preventive visits, but these children were less likely to receive the recommended number of WCC visits. Finding ways to increase the number of WCC visits that all children make is a major challenge, as is conducting studies that prove their worth.

Low literacy and violence among adolescents in a summer sports program

PURPOSE To investigate the relationship between inadequate literacy and violent behavior among adolescents. METHODS This descriptive study involved a convenience sample of 386 adolescents who participated in a summer track and field and literacy program serving youths in low-income neighborhoods in Shreveport, Louisiana, during 1994-1996. Self-reported violence was measured using the Youth Risk Behavior Survey (YRBS) and reading grade levels were measured by the Slosson Oral Reading Test-Revised (SORT-R). RESULTS Youths ranged in age from 11 to 18 years; 66% were male, and 86% were African-American. Forty-three percent of adolescents tested had below-grade reading levels (> or = 2 grades). Participants with below-grade reading skills had higher rates of self-reported violent behaviors compared with those reading at grade level. When gender, race, and age were controlled for, adolescents reading below grade level were significantly more likely to report carrying weapons [odds ratio (OR) = 1.9; 95% confidence interval (CI) 1.1-3.5], carrying guns (OR = 2.6; CI 1.1- 6.2), to have been in a physical fight at school (OR = 1.7; CI 1.1-2.6), and to have been in a physical fight resulting in injuries requiring treatment (OR = 3.1; CI 1.6-6.1). In addition, youths reading below grade level were significantly more likely to be threatened at school with a weapon (OR = 2.1; CI 1.2-3.7) and to report missing days of school in the previous 30 days because they felt unsafe at school (OR = 2.3; CI 1.3-4.3). In characterizing the violence related behaviors, we found that low reading-level adolescents were more likely to be both aggressor/perpetrator and victim (44% vs. 32%; p = .02) and less likely to be only a victim (6% vs. 12%; p = .04) compared to adolescents with grade-appropriate reading skills. CONCLUSIONS Below-grade-level reading was significantly related to violence behaviors among adolescents who volunteered for a summer track and field program. Longitudinal studies are needed to further investigate the relationship of below-grade-level reading and aggressive/perpetrator and victim behaviors.

Growth, survival and viral load in symptomatic childhood human immunodeficiency virus infection.

Background. The relationships among weight and height growth, viral load and survival in HIV-infected children remain unclear. Objectives. To determine whether weight or height growth velocity independently predicts survival and to investigate associations of weight, height and head circumference growth velocities with viral loads in symptomatic HIV-infected children. Methods. We analyzed data from a prospective antiretroviral study utilizing clinical endpoints (PACTG 152). Viral load [log(RNA PCR)] and anthropometric measures 12 weeks before and after viral load measures were available in 494 of 831 children. Interval changes during 24 weeks in z-scores for weight-for-age (&Dgr;WAZ), height-for-age (&Dgr;HAZ) and head circumference-for-age (&Dgr;HCZ) were used as growth velocity surrogates. Logistic regression determined whether &Dgr;WAZ and/or &Dgr;HAZ correlated with survival when age, viral load and CD4+ cell count were controlled. Bivariate analysis assessed correlation among viral load and &Dgr;WAZ, &Dgr;HAZ and/or &Dgr;HCZ. Results. Survival related significantly to height growth velocity (P = 0.03, n = 434) but not to weight growth velocity (P = 0.84, n = 446) or head circumference growth velocity (P = 0.67, n = 148). Viral load was not significantly associated with changes in weight-, height-, or head circumference-for-age z scores (P = 0.86, n = 235; P = 0.07, n = 226; and P = 0.09, n = 165, respectively) in children <30 months of age or with changes in weight- or height-for-age z scores (P = 0.27, n = 259; P = 0.11, n = 251) in older children. Conclusions. Height growth velocity predicted survival independently of age, viral load and CD4+ cell count. Weight, height and head circumference growth velocities were not significantly associated with viral load in symptomatic HIV-infected children in this large prospective trial of nucleoside reverse transcriptase therapy.

Sugar-Sweetened Beverage Intake Trends in US Adolescents and Their Association with Insulin Resistance-Related Parameters

The purpose of this study was to evaluate current sugar-sweetened beverage (SSB) consumption trends and their association with insulin resistance-related metabolic parameters and anthropometric measurements by performing a cross-sectional analysis of the NHANES data during the years 1988–1994 and 1999–2004. Main outcome measures included SSB consumption trends, a homeostasis model assessment of insulin resistance, blood pressure, waist circumference, body mass index, and fasting concentrations of total cholesterol, HDL-cholesterol, LDL-cholesterol, and triglycerides. Although overall SSB consumption has increased, our data suggest that this increase was primarily due to an increase in the amount of SSBs consumed by males in the high-SSB intake group alone. Multivariate linear regression analyses also showed that increased SSB consumption was independently associated with many adverse health parameters. Factors other than SSB consumption must therefore be contributing to the increasing prevalence of obesity and metabolic syndrome in the majority of US children.

Differences in Male and Female Adolescents From Various Racial Groups in the Relationship Between Insulin Resistance-Associated Parameters With Sugar-Sweetened Beverage Intake and Physical Activity Levels

Objective: To describe racial and gender differences in insulin resistance—associated parameters due to sugar-sweetened beverage (SSB) intake and physical activity (PA) levels in the adolescent population. Methods: Data from individuals aged 12 to 19 years from the National Health and Nutrition Examination Survey during the years 1999-2004 were analyzed. SSB intake and PA levels were evaluated in Non-Hispanic whites, Non-Hispanic blacks, and Mexican Americans. Outcome measures included measurements of insulin sensitivity, lipids, blood pressure, waist circumference, and body mass index. Results: Multivariate linear regression analyses showed that anthropometric measurements, metabolic parameters, and indices of insulin resistance differed among the racial groups. Moreover, within each of these racial groups, they differed between the sexes. Conclusions: The differing relationships between insulin resistance—associated parameters and SSB intake and PA levels among racial groups and between the sexes illustrate the importance of race and gender in the investigation of diseases such as obesity and metabolic syndrome.

Monosomy 21q22.11‐q22.13 presenting as a Fanconi anemia phenotype

We report on a 5‐year‐old Caucasian female with multiple anomalies whose deletion, 46,XX,del(21)(q22.11q22.13), was determined by a 105K oligonucleotide‐based microarray. This case is a unique deletion that mimicked Fanconi anemia (combination of thrombocytopenia, thumb anomalies, congenital heart defects, borderline small head circumference, strabismus, hydronephrosis, and significant developmental delay) but testing for Fanconi anemia was negative, as was testing for a wide array of genetic/metabolic conditions. Microarray testing done at 5 months failed to demonstrate the interstitial deletion that was found on a newer generation microarray test performed after 3 years of age. When compared to other reported cases of partial monosomy 21q, the unique features of this case include: (1) cleft palate, although high palate is reported in other cases; (2) neonatal thrombocytopenia requiring platelet transfusion; (3) a platelet function defect, reported previously as platelet storage pool defect as part of a familial platelet disorder; and (4) an immune function defect. Similar to other reported patients with terminal 21q deletion, this child had significant developmental delay, and feeding and growth problems. This case also highlights the ability for newer technology microarrays to identify small interstitial deletions previously missed by an earlier version microarray. The advances in the microarray technologies are allowing us to better define new phenotypes and leading to the identification of a diagnosis for many patients who have been previously undiagnosed. Review of the genes involved in these novel deletions allows the caring physician to design surveillance strategies that are custom‐designed for these unique patients.