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Biomedical subjects

Larry S Webber

Publications and source records attributed to Larry S Webber.

12 recordsLinked to original sources
PubMed2006

Objectively measured physical activity in sixth-grade girls.

OBJECTIVES: To describe the objectively measured physical activity characteristics of a diverse sample of sixth-grade girls, to examine influences on physical activity, and to report compliance with physical activity guidelines. DESIGN: Cross-sectional study. SETTING: Six locations across the United States. PARTICIPANTS: A total of 1578 sixth-grade girls. Accelerometers were worn for 7 days, and data for 6 days were included in the analyses. Main Exposures Race/ethnicity, free or reduced-price lunch, and geographic region. MAIN OUTCOME MEASURES: Six operational definitions of adequate activity (60 or 30 minutes of daily moderate to vigorous physical activity at or above 4.6, 3.8, or 3.0 metabolic equivalents) were used to examine whether girls met physical activity guidelines. RESULTS: Average times spent in sedentary, light, moderate, and vigorous activities were 460, 342, 18, and 6 min/d, respectively. White girls were more active than girls in other race/ethnic groups, and girls who did not receive free or reduced-price lunch were more active than girls who did. Girls in western states were most active. Percentages of girls in compliance with the 6 thresholds for adequate activity varied widely and ranged from 0.6% to 100.0%. CONCLUSIONS: When physical activity is measured objectively and a 4.6-metabolic equivalents cut point for moderate to vigorous physical activity is used, most sixth-grade girls do not meet guidelines for adequate physical activity. One notable finding was the effect of different accelerometer scoring protocols on estimates of compliance. Conceptual and empirical work is needed to define appropriate physical activity for youth using objective physical activity measures.

Child↗
PubMed2006

Vitamin supplement intake is related to dietary intake and physical activity: The Child and Adolescent Trial for Cardiovascular Health (CATCH).

OBJECTIVE: To explore the relationship of multiple-vitamin supplement use with selected food groups, physical activity, lifestyle behaviors, and weight status. SUBJECTS AND METHODS: Two thousand seven hundred sixty-one adolescents in the 12th grade who participated in the fourth Child and Adolescent Trial for Cardiovascular Health study had height and weight measured and completed health behavior survey and food frequency questionnaires. Logistic regression models were used to determine the likelihood of supplement use with health and activity behaviors and dietary intake. RESULTS: Prevalence of multiple-vitamin supplement use among adolescents was 25% and varied by sex and race/ethnicity. Supplement users had higher mean daily intakes of most food groups, but lower intakes of total fat and saturated fat than nonusers. Higher food index scores were positively associated with the likelihood of using multiple-vitamin supplements. Supplement users were more likely to be physically active, participate in team and organized sports, and less likely to be overweight and to watch more than an hour of television per day. CONCLUSIONS: Adolescents who use multiple vitamin supplements have more healthful dietary and lifestyle behaviors than nonusers. Further study on supplement use by adolescents, including other types of supplements used and reasons for use, is warranted.

Adolescent↗
PubMed2006

Serum homocysteine is related to food intake in adolescents: the Child and Adolescent Trial for Cardiovascular Health.

BACKGROUND: An understanding of the relation in adolescents between serum homocysteine and foods rich in vitamin B-6, vitamin B-12, and folate is important because high homocysteine concentrations in childhood and adolescence may be a risk factor for later cardiovascular disease. However, little is known about the relation between food intake and homocysteine in adolescents. OBJECTIVE: Five years after national folic acid fortification of enriched grain products, cross-sectional relations between food intake and serum homocysteine concentrations were examined in 2695 adolescents [x age: 18.3 (range: 15-20) y] enrolled in the Child and Adolescent Trial for Cardiovascular Health. DESIGN: A nonfasting blood specimen was analyzed for serum homocysteine, folate, and vitamins B-6 and B-12. Dietary intake was assessed by using a food-frequency questionnaire. Multiple regression analyses were used to evaluate the relation of intakes of whole grains, refined grains, fruit, vegetables, dairy products, red and processed meats, and poultry with serum homocysteine concentrations after adjustment for demographic characteristics, lifestyle factors, and food intake. RESULTS: Serum homocysteine concentrations were lower with greater intakes of whole grains (P for trend = 0.002), refined grains (P for trend = 0.02), and dairy foods (P for trend <0.001); were higher with greater intake of poultry (P for trend = 0.004); and were not related to intakes of fruit, vegetables, or red or processed meat. After additional adjustment for serum B vitamins, the relations of serum homocysteine with most food groups were attenuated. CONCLUSION: These observational findings suggest a beneficial effect of whole-grain, refined-grain, and dairy products on serum homocysteine concentrations in an adolescent population.

Adolescent↗
PubMed2005

Use of the SF-8 to assess health-related quality of life for a chronically ill, low-income population participating in the Central Louisiana Medication Access Program (CMAP).

OBJECTIVES: The utility of the SF-8 for assessing health-related quality of life (HRQL) is demonstrated. Race and gender differences in physical component (PCS) and mental component (MCS) summary scores among participants in the CENLA Medication Access Program (CMAP), along with comparisons to the United States population are made. METHODS: Age-adjusted multiple linear regression analyses were used to compare 1687 CMAP participants to the US population. Internal race and gender comparisons, adjusting for age and the number of self reported diagnoses, were also obtained. The paired t-test was used to assess 6-month change in PCS and MCS scores for a subset of 342 participants. RESULTS: CMAP participants have PCS and MCS scores that are significantly 10-12 points lower than the US population, indicating lower self-reported HRQL. Females have significantly higher PCS and significantly lower MCS than males. African-Americans have significantly higher MCS than Caucasians. Significant increases in both PCS and MCS were observed for the subset of participants after 6 months of intervention. CONCLUSIONS: The expected lower baseline PCS and MCS measures and the expected associations with age and number of diagnoses indicate that the SF-8 survey is an effective tool for measuring the HRQL of participants in this program. Preliminary results indicate significant increases in both PCS and MCS 6 months after intervention.

Adult↗
PubMed2005

Design of the Trial of Activity in Adolescent Girls (TAAG).

The primary aim of the Trial of Activity in Adolescent Girls (TAAG) is to test an intervention to reduce by half the age-related decline in moderate to vigorous physical activity (MVPA) in middle school girls. The intervention will be evaluated using a group-randomized trial involving 36 middle schools. The primary endpoint is the mean difference in intensity-weighted minutes (i.e., MET-minutes) of MVPA between intervention and comparison schools assessed using accelerometry. The TAAG study design calls for two cross-sectional samples, one drawn from 6th graders at the beginning of the study and the second drawn from 8th graders at the end of the study following the 2-year implementation of the intervention. An important strength of this design over a cohort design is the consistency with the goals of TAAG, which focus on environmental-level rather than individual-level interventions to produce change. The study design specifies a recruitment rate of 80% and a smaller sample of girls at baseline (n=48 per school) than at follow-up (n=96 per school). A two-stage model will be used to test the primary hypothesis. In the first stage, MET-weighted minutes of MVPA will be regressed on school, time (baseline or follow-up), their interaction, ethnicity and week of data collection. The second stage analysis will be conducted on the 72 adjusted means from the first stage. In the main-effects model, we will regress the follow-up school mean MET-weighted minutes of MVPA on study condition, adjusting for the baseline school mean. The TAAG study addresses an important health behavior, and also advances the field of group-randomized trials through the use of a study design and analysis plan tailored to serve the main study hypothesis.

Adolescent↗
PubMed2005

The obesity epidemic: incidence and prevalence.

Obesity is a major public health problem in the United States and in Louisiana in particular. The prevalence of both overweight and obesity has increased in the past two decades. National studies and studies conducted in Louisiana in adults and children have shown that overweight and obesity are related to conditions such as hypertension, diabetes, stroke, and insulin resistance syndrome. Obesity tracks over time, with obese children and adolescents being more likely to become obese adults. Numerous intervention models to modify eating and exercise behaviors have been conducted with children in Louisiana and have shown that it is possible to reduce fat and saturated fat intakes and increase the amount of moderate to vigorous daily physical activity. More research is needed, however, in both health education programs and environmental influences if we are to be effective in making the necessary changes in eating and physical activity habits of children, adolescents, and adults to reduce the prevalence of obesity.

Adult↗
PubMed2004

Profiles of the adolescent smoker: models of tobacco use among 9th grade high school students: Acadiana Coalition of Teens against Tobacco (ACTT).

BACKGROUND: Tobacco use, underreported among Louisiana youth, was examined among 9th grade students in south central Louisiana; profiles of tobacco use were developed to inform adolescent tobacco control programs. METHODS: Cross-sectional Health Habits Survey was administered to 4,808 students who were about 15 years old, predominantly white, with gender almost evenly distributed. Saliva samples were collected from 1,966 students. Analysis of a subsample resulted in good concordance between self-reported daily tobacco use and cotinine. RESULTS: About 58% of students ever smoked a cigarette, 25% had a cigarette within the previous 30 days, 17% smoked within the past 7 days and almost 8% reported smokeless tobacco use. Smokeless tobacco use was greater for males than females. Caucasians, native Americans, and Latinos were more likely to smoke than African-Americans. Social relationships associated with adolescent smoking included having a friend, parent and/or sibling who smoked, having a friend who consumed alcohol, and being around people who used alcohol for "kicks." The attitudes of nonsmokers were consistently in the positive direction relative to disapproval of tobacco and alcohol use. The profiles differed demographically between black and white students. CONCLUSIONS: These data provide the needed information for guiding health promotion and tobacco control efforts, specifically regarding black/white differences.

Adolescent↗
PubMed2003

Maintenance of effects of the eat smart school food service program: results from the CATCH-ON study.

The Child and Adolescent Trial for Cardiovascular Health (CATCH) Eat Smart Program targeted the food service of the 56 CATCH intervention elementary schools to effect positive changes in the total fat and saturated fat content of school lunch. Maintenance of the food service intervention in former intervention (n = 56) and control (n = 20) schools was evaluated 5 years postintervention. After 5 years of follow-up and no further intervention, the former CATCH intervention schools not only maintained prior levels but also had further decreases in the mean percentage of calories from total and saturated fat to 31% and 10.4%, respectively. Significant decreases in these nutrients were also observed in the former CATCH control schools; however, the former intervention schools more closely approached the Eat Smart goal for total fat Overall, sodium levels rose in both school conditions and did not differ significantly at follow-up.

Adolescent↗
PubMed2003

Maintenance of effects of the CATCH physical education program: results from the CATCH-ON study.

Long-term maintenance effects of physical education (PE) curriculum and staff development programs have not been studied. The authors assessed the sustainability of the Child and Adolescent Trial for Cardiovascular Health (CATCH) PE intervention using direct observations of 1,904 PE lessons in former intervention and control schools in four U.S. states 5-years postintervention. Student physical activity levels, lesson contexts, and level of CATCH PE training of teachers were analyzed. Student energy expenditure levels and proportion of PE time in moderate-to-vigorous physical activity in intervention schools were maintained 5 years later, but vigorous activity declined sharply. Meanwhile, postintervention gains in former control schools, influenced by delayed program implementation and secular trends, resulted in a convergence of activity levels in intervention and control schools. Use of CATCH PE curricula was associated with increased levels of teacher training and school support for PE in both former intervention and control schools.

Child↗
PubMed2002

Tracking of physical and physiological risk variables among ethnic subgroups from third to eighth grade: the Child and Adolescent Trial for Cardiovascular Health cohort study.

BACKGROUND: The Child and Adolescent Trial for Cardiovascular Health (CATCH), a multisite field trial, tested the effectiveness of multiple interventions for cardiovascular disease risk behaviors in children in third through fifth grades. This paper reports the tracking of physiologic variables through eighth grade. METHODS: The cohort began with 5,106 third grade students from diverse ethnic backgrounds: 69% Caucasian, 14% Hispanic, 13% African American, and 4% other. Seventy-two percent of students were remeasured. Measures described are serum lipids, blood pressure, and body anthropometrics. Tracking was examined across three time points (third, fifth, and eighth grades) with a scaled Kendall concordance coefficient and percentage retention within quintiles across time. RESULTS: For the overall sample, tacking was strongest for body mass index (BMI) (Kendall coefficient = 0.86) and weight (0.86), followed by skinfold thicknesses (0.72-0.78), serum lipids (0.67-0.72), and blood pressure (0.45-0.51). For BMI, 96% of students stayed within +/-1 quintile from third to fifth grades; 90% stayed within this range from third to eighth grades. CONCLUSIONS: There were small but noticeable gender and ethnic differences: tracking was stronger among boys and African American students. These results demonstrate that the children's relative level of cardiovascular risk remained stable over a 6-year period.

Adolescent↗
PubMed2002

Maintenance of lightweight correlates with decreased cardiovascular risk factors in early adolescence.

PURPOSE: To describe predictors of lightweight in 11-year-olds and how weight changes between ages 9-11 years affected selected cardiovascular risk factors. METHODS: Cohort study among an ethnically and geographically diverse group of 5098 nine-year-olds who participated in the Child and Adolescent Trial for Cardiovascular Health (CATCH) and were followed from 1991 to 1994 until age 11 years. Lightweight (body mass index [BMI] <15th percentile) was defined from gender- and age-adjusted data on the total population in the National Health and Nutrition Examination Survey I of 1971 to 1973. Weight (BMI) category at follow-up (age 11 years) was the dependent variable in the logistic regression. Gender, race/ethnicity, school site, weight category at baseline, and participation in the CATCH (intervention or control group) were examined for possible predictors. RESULTS: The prevalence of lightweight was much lower than the 15% expected at both ages 9 and 11 years; 4.7% for males (M) and 7.4% for females (F) and at age 11 years; 5.9% for M and 8.3% for F. Lightweight at age 9 years was the best predictor of lightweight at age 11 years (OR = 56.8; CI 41.3, 78.2). Normal-weight children who entered the overweight category exhibited striking adverse percent changes in serum cholesterol and in both serum high-density cholesterol and apolipoprotein B cholesterol levels. Among children in each weight group at age 9 years, the heavier children at age 11 years had higher percent changes in systolic blood pressure, and lower times on the 9-min run. Maintenance of lightweight was associated with the most favorable pattern of cardiovascular risk factors. Differences between groups were not found for percent change in total calorie intake or percentage of calories from fat. Normal-weight children who became overweight exhibited striking percentage increases in levels of serum cholesterol and in serum apolipoprotein B cholesterols. CONCLUSIONS: Population-based anticipatory guidance about weight should focus on all children in mid-childhood, not only those at the upper extremes of weight. These who are genetically lean and healthy should be encouraged to remain so. Maintenance or achievement of lightweight was associated with favorable changes in systolic blood pressure in CATCH children during early adolescence. Those below the 5th percentile should be assessed and treated if eating disorders, undernutrition, or chronic illness are present. Optimal weight and optimal health should not be confused.

Blood Pressure↗