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L S Webber

Publications and source records attributed to L S Webber.

At least 145 records · Page 8Linked to original sources
PubMed1984

Recruitment and participation of children in a long-term study of cardiovascular disease: The Bogalusa Heart Study, 1973-1982.

The Bogalusa Heart Study has been highly successful in recruitment and screening of children and adolescents in Bogalusa, Louisiana. From 1973 to 1982 in four cardiovascular risk factor surveys, 80-93% of the biracial pediatric population was examined. Overall participation rates compare favorably with those of similar studies. The authors examine methods and strategies involved in obtaining community support, identifying and contacting the eligible population, and implementing recruitment campaigns. Several of the more successful motivational efforts are described. Attrition and the broader problem of decreasing participation rates in older adolescents are examined. Recommendations are advanced for dealing with this problem age group.

Adolescent↗
PubMed1984

High blood pressure in the young.

Essential hypertension begins in early childhood. Current evidence suggests that those children persisting at high levels over time may be considered to have essential hypertension. The evaluation of high levels is best judged from blood pressure percentile grids representing population measurements, as long as the methods used to measure blood pressure and to generate the grids are similar. Resting, basal blood pressure measurements are more reproducible and are better for following the time course of blood pressure levels in children. Measurements should be made in an unhurried, relaxed atmosphere by trained observers using adequately lighted instruments placed at eye level and a cuff size appropriate for the child's arm length and circumference. Repeated observations and serial blood pressure measurements of growing children are necessary for judgments of abnormal levels. There is a progressive rise of approximately 1.5 mm Hg systolic and 1 mm Hg diastolic pressure per year of age, but blood pressure levels in the growing child are more closely related to height. In most instances elevated blood pressure levels in children cannot be attributed to secondary causes. Various hemodynamic and biochemical mechanisms have been identified in the early stages of hypertension, and mechanisms contributing to the development of hypertension may be of different magnitudes in black children and white children. Studies following young adults over many years have shown the predictive value of baseline blood pressure levels for subsequent hypertension. Children tracking at the high percentiles can be identified and are candidates for early intervention. The key to early prevention of essential hypertension is to influence children and adolescents to adopt lifestyles that promote good health and prevent development of cardiovascular risk factors.

Adolescent↗
PubMed1984

Effect of interviewer recording practices on nutrient intake--Bogalusa Heart Study.

Recording practices of interviewers who independently collected dietary recalls from children for the same 24-hour eating period were analyzed. For each duplicate pair, three aspects of recording were examined: name of foods, quantity assessed from child, and food identification number selected prior to nutrient analysis. There was a 76% agreement on recorded food names. For those matched foods, 87% were assigned the same food identification numbers. Differences regarding quantities of foods were greatest for liquids, meats, and sweets. Recalls were analyzed for nutrient content on the computerized Extended Table of Nutrient Values. A paired t-test statistic showed significant sequence effect, with total energy, sugar, fat, and unsaturated fat higher for the first interview. Significant differences in nutrient intake were noted for the interviewer pair with highest percentage of foods differing by name. After-school snack assessment was the most variable eating occasion. Entry-level criteria for trained interviewers are proposed to establish standardized interviewing techniques when applying the 24-hour recall tool to child respondents.

Child↗
PubMed1983

Tracking of cardiovascular disease risk factor variables in school-age children.

Persistence in ranks (tracking) for cardiovascular disease risk factor variables was examined in 2236 children who were screened three times over a 5-yr period. As expected, the greatest persistence was noted for height (r = 0.47-0.99) and weight (r = 0.70-0.96). Correlation coefficients for systolic blood pressure and diastolic blood pressure ranged from 0.38 to 0.66 and 0.22 to 0.49 respectively. Among lipids, the correlations were highest for serum beta-lipoprotein cholesterol ranging from 0.62 to 0.78. For those children who were at or above the 90th percentile on a risk factor variable during the first examination, a tendency to retain their ranks in the second and third examinations was noted. For systolic blood pressure, 35% of those initially high remained high in the second examination and 30% in the third examination. Correspondingly, for those initially high for beta-lipoprotein cholesterol, 47 and 41% remained high. A linear discriminant model was used to distinguish characteristics of children who persisted at high rankings and those who did not. The model was effective for total and beta-lipoprotein cholesterol, but only moderately so for systolic blood pressure.

Adolescent↗
PubMed1983

Distributions of serum lipoproteins in children by repeated measurements.

Serum lipids and lipoproteins were measured three times over 6 years in a total-community study of children in Bogalusa, Louisiana. Interrelationships and changes in the distributions of serum lipoprotein cholesterol levels were examined in terms of variability and precision of the laboratory measurements. Although distributions of serum lipoprotein cholesterol variables shifted among the three surveys, precision increased markedly as indicated by a decrease in the coefficient of variation for measurement error for total cholesterol, alpha-lipoprotein cholesterol, and triglycerides between Year 1 and Year 4 and then stabilized. Pre-beta-lipoprotein cholesterol was the most difficult variable to measure. The range and magnitude of correlation coefficients between lipid and lipoprotein variables were very similar. Despite quality controls, efforts to standardize laboratory analyses, and adherence to protocols, fluctuations in distributions of lipids and lipoproteins occurred when the same population was restudied. Long-term studies for coronary artery disease prevention should include laboratory safeguards that help to distinguish modest population changes in serum lipids and lipoproteins from laboratory drift.

Adolescent↗
PubMed1983

A simplified inventory method for quantitating dietary sodium, potassium, and energy.

During an 8-day observation of the effect of K+ supplementation (80 mEq) on Na+ and K+ balance in a biracial sample of young adults (n = 14), a Food Inventory was developed to monitor dietary Na+, K+, and energy intakes. Urine and stool samples provided electrolyte output measures. The Food Inventory reduced heterogeneity of foods consumed and simplified quantitation. It was self-administered and consisted of 10 preselected foods categories, each containing 24 to 40 food items. Energy was higher for whites and for males (p less than 0.10). Both total Na+ intake and Na+ per 1000 kcal were higher for males. A 1.4 Na+/K+ dietary ratio was observed. After K+ supplementation, Na+ balance was negative; a marked natriuresis occurred, being more consistent for Blacks. With K+ supplementation a positive K+ balance occurred and was more evident in Blacks. Significant positive correlations of daily Na+ and K+ intakes with output were observed with higher correlation for K+ than Na+. This dietary assessment method can be useful in metabolic or behavioral studies requiring quantitation of electrolytes and energy.

Adolescent↗
PubMed1983

Quantification of lipoprotein cholesterol in serum from children with different lipoprotein profiles: heparin-calcium precipitation and ultracentrifugation compared.

We compared the serum lipoprotein cholesterol concentrations in subgroups of children (n = 360), ages 5-17 years, as measured by the heparin-Ca2+ and preparative ultracentrifugation methods. Children were grouped from the total population on the basis of their previous results for serum beta- and pre-beta-lipoprotein cholesterol (Group I: low beta- and low pre-beta-; Group II: high beta- and low pre-beta; Group III: high beta- and high pre-beta-; Group IV: low beta- and high pre-beta-). The values for very-low-density (VLDL) cholesterol by ultracentrifugation method were 44, 53, 15, and 10 mg/L greater than the values for pre-beta-lipoprotein cholesterol by the heparin-Ca2+ method in Groups I, II, III, and IV, respectively; the differences were not significant in Group IV. The values of low-density (LDL) cholesterol were 64, 137, 144, and 73 mg/L less than the values for beta-lipoprotein cholesterol in Groups I, II, III, and IV, respectively (p less than 0.005). On the other hand, high-density (HDL) cholesterol concentrations in the respective four groups were 10, 37, 93, and 52 mg/L greater than alpha-lipoprotein cholesterol concentrations; the differences were significant for Groups II, III, and IV (p less than 0.005). Overall, the values for LDL-cholesterol correlated highly with beta-lipoprotein cholesterol (r = 0.94), whereas correlations for VLDL- and HDL-cholesterol values with pre-beta-lipoprotein cholesterol (r = 0.76) and alpha-lipoprotein cholesterol (r = 0.77) were somewhat lower. The differences between these two methods may result from their different operational definitions for measuring serum lipoproteins and the possibility that without appropriate corrections the values obtained by preparative ultracentrifugation do not serve as reference values.

Adolescent↗
PubMed1982

Cardiovascular risk factors in children. Should they concern the pediatrician?

There is evidence that atherosclerosis, coronary artery disease, and essential hypertension begin early in life. The Bogalusa (La) Heart Study has examined cardiovascular risk factors and their determinants during the pediatric age span in a total community study. Reliable measurements were obtained and then analyzed to identify "tracking" of risk factors over time and clusters or aggregations of various risk factors at high levels. Serum lipoprotein levels, obesity, BP, and plasma insulin levels were all correlated after a glucose load, implying causal interrelationships. Although such relationship are only partly elucidated, the associations potentially enhance premature atherosclerosis. Certain kinds of behavior, for example cigarette smoking and type A behavior, may also contribute to early coronary artery disease. Our observations suggest that practicing physicians should assess risk factors in children and encourage changes in life-style to combat the high incidence of coronary artery disease and essential hypertension in the United States.

Adolescent↗
PubMed1982

Type A coronary-prone behavior pattern and cardiovascular risk factor variables in children and adolescents: the Bogalusa Heart Study.

The relationship between Total score from the Hunter-Wolf A-B Self-Rating Scale for children (and derived Factors) and several cardiovascular risk factor variables was observed in children ages 10-17 in a biracial community. After analysis, effects of age, weight and height were removed from the Total A-B score, each Factor score, and risk factor variable. Differences in risk factor variables were observed in relation to A-B, race and sex. For each sex-race group, the four Factor scores and Total score were ranked into quintiles. Children in the upper quintile referred to as Type A children and those in the lower quintile, Type B. For Factor 1, which describes eagerness and energy in children (Eagergy), significant mean differences were found for serum total, beta- and pre-beta-lipoprotein cholesterol and triglycerides. In each instance, children classified as Type A exhibited approximately 10 mg/dl higher readings, except for pre-beta-lipoprotein cholesterol in which a 2 mg/dl difference was noted. Two significant second order interactions were found for systolic and diastolic blood pressure. Black boys who scored in the A direction had higher systolic blood pressures, while Type A girls had higher diastolic blood pressures than their Type B counterparts (p less than 0.05). For Factor IV, which is related to feeling hurried, there was an approximate 10 mg/dl difference in serum total and beta-lipoprotein cholesterol in the direction opposite to that predicted. Although the relationships between A-B coronary behavior pattern and risk factor variables in children are of low magnitude, the relationships are being observed in the direction that might be predicted. Measurement of Type A in children requires further refinement in concept identification and valid measurement.

Adolescent↗
PubMed1982

Influence of milk source on serum lipids and lipoproteins during the first year of life, Bogalusa heart study.

An epidemiological study of coronary heart disease risk factor variables in a cohort of 440 infants from birth to age 4 was conducted in Bogalusa, LA. This report evaluates differences in serum lipids and lipoproteins and dietary intakes of infants fed various milk or formula types during the 1st year of life. There were significant positive correlations between serum total cholesterol and beta-lipoprotein cholesterol levels and consumption of cow's milk at 6 months of age. The cow's milk-fed infants at 6 months had significantly greater intakes of animal protein and saturated fat as compared to the formula-fed groups. At 1 yr these differences were not found, possibly because of the heterogeneity of the eating patterns of infants by this age. Serum lipid and lipoprotein levels appear to be responsive to concurrent dietary intake of fat and cholesterol in 6-month-old infants.

Animals↗
PubMed1982

Resting heart rate and pressure-rate product of children in a total biracial community: the Bogalusa Heart Study.

Resting heart rates were ascertained during the 1978-1979 school year in 3590 children aged 5-17 years in the biracial geographic population of Bogalusa, Louisiana. These rates were found to be relatively independent of the method of measurement, whether supine by physician's stethoscope or dressed sitting radial pulse taken by a nurse, and in either case adhering to a strict measurement protocol. Apart from the known influences of age and sex, the authors found a small but consistent racial influence, with whites having 3-4 beats/min higher rates than blacks. Controlling for age, the authors found heart rate to be positively correlated with blood pressure in whites and with subcapsular skinfold thickness in boys. No consistent relation between heart rate and amount of cigarettes smoked was observed. Boys in the upper five percentiles of blood pressure-heart rate ("double") product values were found to have about twice the subscapular skinfold thickness compared to the lower five percentiles. Likewise, boys in the upper five percentiles of subscapular skinfold thickness had significantly increased double products. Since the double product is an index of cardiac oxygen consumption, this finding could point to a possible etiologic link between obesity and chronic cardiac stress in males beyond the mediation of lipoproteins, cholesterol, and diabetes mellitus in contributing to atherosclerotic heart disease, but this issue needs further study. Ascertainment of resting heart rate provides an additional parameter in the study of cardiovascular risk factor variables, in youth as in adulthood, to supplement the natural history of the atherosclerosis-hypertension syndrome with its sequelae.

Adolescent↗
PubMed1982

Hereditary and environmental influences on cardiovascular risk factors for children: the Bogalusa Heart Study.

This paper reports on a study of all school-age children from Bogalusa, Louisiana, examined during the 1973-1974 and 1976-1977 school years by personnel of the Specialized Center of Research-Arteriosclerosis. For these children, the authors estimated the proportion of total variability in risk factors for atherosclerosis resulting from the influences of heredity (h2) and of common environment (c2). The authors' method of classifying half siblings underestimated h2 but overestimated c2. The results showed statistically significant values of h2 for height (0.91), weight (0.90), systolic blood pressure (.137), triglycerides (0.88), beta-lipoprotein (1.16), and alpha-lipoprotein (0.63). In addition, c2 was statistically significant for height (0.20), weight (0.32), triceps skinfold (0.19), systolic blood pressure (0.30), beta-lipoprotein (0.21), and alpha-lipoprotein (0.13). Because of the definition of c2, all traits for which it is significant must increase in value for some Bogalusa environments, and decrease for others. Therefore, for such traits, future analyses may identify favorable common environments that intervention studies can use to decrease the risk of atherosclerosis in Bogalusa. The values found for h2 and c2 in Bogalusa were compared and contrasted with values found for other communities.

Adolescent↗
PubMed1982

Heart disease in a total population of children: the Bogalusa Heart Study.

A cross-sectional survey of a total semirural biracial population of children was conducted to determine the prevalence and types of cardiac disease. Of 4,074 children examined, 146 were thought to have significant cardiac murmurs. One hundred thirteen of these participated in a follow-up study in which they received a physical examination by two adult cardiologists and one pediatric cardiologist, a chest roentgenogram, and an electrocardiogram. An attempt at a consensus concerning the diagnosis was made by subsequent discussions among the physicians. The discussions were repeated in 33 cases after a phonocardiogram and/or an echocardiogram were done. In 20 children, cardiac disease was diagnosed by at least two cardiologists. Supplementing this with information from hospital records on some of the children and data from a previous study, cardiac abnormalities were diagnosed in 25 children from the total population (0.6%). A disproportionately greater number of black children and boys were affected. Thirteen children had congenital heart disease, five had mitral valve prolapse, and only two had rheumatic heart disease. The prevalence of mitral valve prolapse was probably underestimated in this study.

Adolescent↗
PubMed1982

Factor analytic study of the Piers-Harris Children's Self-Concept Scale.

A factor analysis of the Piers-Harris Self-Concept Scale was conducted with a biracial u sample of children over a wide age range. The Scale was completed by 348 10-17 year old students in a rural community. Seven factors of 10 had sufficient item loadings to be interpretable. Six matched those found in the manual and an additional factor was found relating to Aggression. Race, sex, and age relationships are also reported for these seven factors.

Journal Article↗