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Biomedical subjects

B A Dennison

Publications and source records attributed to B A Dennison.

11 recordsLinked to original sources
PubMed1994

Dietary sources of fats and cholesterol in US children aged 2 through 5 years.

OBJECTIVES: This study of lipid intakes among preschool children (1) analyzed the contributions of 38 food groups to fat, saturated fat, and cholesterol intakes; (2) estimated the effects of food substitutions on intakes; and (3) examined demographic differences in food group intake and food group sources of these lipids. METHODS: The sample consisted of 547 children, aged 2 to 5 years, from the US Department of Agriculture's 1985 and 1986 Continuing Surveys of Food Intakes by Individuals. Dietary information for 4 nonconsecutive days throughout a year was used. All foods were classified into groups and the lipids contributed from each group were computed. RESULTS: Over 80% of the children consumed more total fat, saturated fats, and cholesterol than is recommended. The major source of total fat and saturated fats was whole milk; the major sources of dietary cholesterol were eggs and whole milk. Children's food consumption patterns differed by region of the country and race/ethnicity, providing opportunities to refine nutrition education interventions and evaluations. CONCLUSIONS: By substituting lower-fat foods for the major sources of saturated fats, significant reductions in preschool children's intakes of saturated fats, fat, and dietary cholesterol could be achieved.

Child Nutritional Physiological Phenomena↗
PubMed1994

Challenges to implementing the current pediatric cholesterol screening guidelines into practice.

OBJECTIVE: The Expert Panel on Blood Cholesterol Levels in Children and Adolescents of the National Cholesterol Education Program (NCEP) recommends selective screening of children for high blood cholesterol. We determined the number of children, who, according to the guidelines, should be targeted for cholesterol screening. DESIGN: Population survey. SETTING: Permanent household residents in Otsego County, NY. PARTICIPANTS: Total population-based sample of 17,444 households (86.6% response rate) including 44,565 participants, of whom 10,457 were children, aged 2 through 19 years. MAIN OUTCOME MEASURES: Percent of children qualifying for cholesterol screening under the NCEP Children's Panel guidelines. RESULTS: Children from two-parent families were more likely to have known family history of coronary heart disease (CHD) before 60 years of age (41.8% vs 25.8%, P < .001), and twice as likely as children from single-parent families to have known parental hypercholesterolemia (18.8% vs 9.5%, P < .001). Only 39% of parents reported having had their cholesterol level checked; they were better educated and more likely to have health insurance. Parents with a first-degree relative with CHD before 60 years of age were more likely to report having their cholesterol level checked and to report a high cholesterol level. We calculated that 27% of children (18% of children from single-parent households and 29% of children from two-parent households) would report a known family history of premature CHD (ie, CHD before 55 years of age) and qualify for lipoprotein analysis, and that 11% of children would qualify for total cholesterol screening because of known parental hypercholesterolemia without a family history of premature CHD. Thirty-five percent of children had incomplete or unavailable family health history and/or unknown parental cholesterol status. CONCLUSIONS: In this population, 38% of children would be targeted for cholesterol screening, exceeding the estimate of the NCEP Children and Adolescents Panel. The selection process, however, would tend to miss children from single-parent families, children with incomplete family health history, and children whose parents have not had their cholesterol levels measured. The currently recommended pediatric cholesterol screening policy needs to be evaluated further in additional communities and population settings. Alternative cholesterol screening strategies are needed when family health history is incomplete and/or parental cholesterol status is unknown.

Adolescent↗
PubMed1993

Randomized, double-blind, placebo-controlled, two-period crossover clinical trial of psyllium fiber in children with hypercholesterolemia.

A randomized, double-blind, placebo-controlled, crossover clinical trial was designed to test the efficacy of psyllium fiber in lowering elevated low-density lipoprotein cholesterol (LDL-C) levels in children 5 to 17 years of age. Subjects with LDL-C levels > 2.84 mmol/L (110 mg/dl) after at least 3 months of a low total fat, low saturated fat, low cholesterol diet were enrolled. Two ready-to-eat cereals, with water-soluble psyllium fiber (6 gm/day) and without, were prescribed for 4 to 5 weeks each, with an intervening 2-week washout phase. Reported compliance rates exceeded 80% in the 20 subjects who completed the study. Mean initial total cholesterol, LDL-C, high-density lipoprotein cholesterol, and triglyceride values were 5.23, 3.60, 1.18, and 2.22 mmol/L, respectively. Comparison of the mean changes (from baseline) in lipid values after the two periods of cereal consumption revealed no statistically nor clinically significant differences in total cholesterol, LDL-C, or high-density lipoprotein cholesterol values. Triglyceride levels, however, increased 0.68 mmol/L (26 mg/dl; p < 0.05) after the control cereal in comparison with the psyllium cereal. No significant differences were noted in the children's dietary intake (assessed by 7-day diet records) during the two study periods. Measures of growth (height, weight, and skin-fold thicknesses), and blood vitamin (folic acid; vitamins A, D, and E) and mineral (iron, zinc, and calcium) levels were not affected. In this study, psyllium fiber had no additional lowering effect on total cholesterol or LDL-C levels in children who were already following low total fat, low saturated fat, low cholesterol diets.

Adolescent↗
PubMed1990

Measurement of apolipoprotein B as a screening test for identifying children with elevated levels of low-density lipoprotein cholesterol.

We compared the efficacy of two screening tests, measurement of apolipoprotein B (apo B) levels and measurement of serum total cholesterol levels, in detecting elevated low-density lipoprotein cholesterol (LDL-C) values in children. We studied 2850 children, aged 5 to 17 years, who had fasting lipid, lipoprotein, and apolipoprotein levels measured as part of the Bogalusa Heart Study. The test characteristics of apo B were superior to those of serum total cholesterol in screening children to detect elevated levels of LDL-C (greater than or equal to 95th percentile) and moderately elevated LDL-C levels (greater than or equal to 80th percentile). Unusually high or low values of high-density lipoprotein cholesterol are responsible for most of the misclassification that occurs when measurement of total cholesterol is used as a screening test for identifying children with elevated levels of LDL-C. This confounding effect of high-density lipoprotein cholesterol was eliminated when measurement of apo B levels was used as a screening test. Because the apo B test is more specific at a given sensitivity than the total cholesterol test, the apo B test can cost more and still be less expensive as a screening strategy. As the methods for determining apolipoprotein levels become standardized and readily available, the measurement of apolipoproteins could be developed into superior screening tests for the identification of patients with dyslipidemias.

Adolescent↗
PubMed1990

Serum total cholesterol screening for the detection of elevated low-density lipoprotein in children and adolescents: the Bogalusa Heart Study.

The use of serum total cholesterol measurement was evaluated as a screening tool to predict elevated levels of low-density lipoprotein cholesterol in 2857 children and adolescents, aged 5 to 17 years, examined in 1981 and 1982. Subjects were from the biracial community of Bogalusa, Louisiana. For selected serum total cholesterol values (150 to 210 mg/dL, 3.88 to 5.43 mmol/L), sensitivities were higher for blacks than whites and higher for females than males, whereas the positive predictive values were higher for whites than blacks and higher for males than females. With the age-, race-, and sex-specific 95th percentiles of serum total cholesterol levels as cutoff points, only 44% to 50% of subjects with elevated low-density lipoprotein cholesterol levels (greater than or equal to 95th percentile) were detected, and approximately 50% of those identified had false-positive results. Lowering the serum total cholesterol cutoff point increased the sensitivity, but decreased the specificity and positive predictive value. At the 75th percentiles of serum total cholesterol levels, sensitivities were 92% to 95% for females and 100% for males and specificities were 78% to 79%, but the false-positive results increased to 81% to 84%. The low cost and ease of obtaining serum total cholesterol measurements contribute to its appeal as a screening tool for hyperlipidemia. However, its poor test characteristics make serum total cholesterol measurement inefficient as a screening tool for detecting elevated levels of low-density lipoprotein cholesterol in children and adolescents.

Adolescent↗
PubMed1989

Parental history of cardiovascular disease as an indication for screening for lipoprotein abnormalities in children.

We studied the relationship between parental history of cardiovascular disease and risk for adverse lipid and lipoprotein levels in a total community study of 3313 children (ages 4 to 17 years, 63% white, 37% black). Older white children (11 to 17 years) with a parental history of heart attack or diabetes were 4.3 and 5.6 times, respectively, more likely to have high levels (greater than or equal to 95th percentile) of serum total cholesterol than those without such a history (all p less than 0.05). White children with a parental history of heart attack or diabetes were twice as likely to have an elevated (greater than or equal to 95th percentile) low-density lipoprotein cholesterol (LDL-C) level than those without such a history (both p less than 0.05). In contrast, parental history of cardiovascular disease did not predict elevated levels of total cholesterol or LDL-C in black children. However, older black children with a parental history of heart attack, hypertension, or diabetes were 4 1/2 to 5 times more likely to have low levels (less than or equal to 5th percentile) of high-density lipoprotein cholesterol than those without such a history (all p less than 0.05). Only 40% of white children and 21% of black children with elevated LDL-C levels had a parental history of vascular disease. These findings raise questions about the current practice of screening only children with a family history of cardiovascular disease to identify those with elevated total cholesterol and LDL-C levels.

Adolescent↗
PubMed1988

Childhood physical fitness tests: predictor of adult physical activity levels?

Regular physical activity has both short- and long-term health benefits in adults. No study has investigated childhood determinants of adult physical activity patterns, however. In a nonconcurrent prospective study, the physical activity levels of 453 young men, 23 to 25 years of age, were compared with their physical fitness test scores as children (10 to 11 years of age and 15 to 18 years of age). The physically active adults had significantly better childhood physical fitness test scores than did the inactive adults. In 224 children, 2 years of fitness test results were available. The risk of physical inactivity in young adulthood was linearly related to the number of low scores on the 548.6-m (600-yd) run and sit-ups tests as children (P less than .001). In stepwise multivariate discriminant analysis, the childhood 548.6-m run score was the best discriminator between currently physically active and inactive adults. Reported parental encouragement of exercise, level of education, participation in organized sports after high school, and reported spousal encouragement of exercise also contributed significantly to the discriminant function. These results demonstrate that physical fitness testing in boys facilitates the identification of those at increased risk of becoming physically inactive young adults.

Adolescent↗
PubMed1982

Radiogenic changes in the behavior and physiology of the spontaneously hypertensive rat: evidence for a dissociation between acute hypotension and incapacitation.

Immediately following exposure to a sufficiently large dose of ionizing radiation, rats and several other species experience a transient period of acute hypotension and an accompanying deficit in performance. Although significant correlations have been reported between the drop in blood pressure and the early transient incapacitation (ETI) and a causal relationship has been suggested, the extent to which hypotension precipitates the occurrence of the behavioral deficits remains uncertain. The present experiments investigated both radiogenic blood pressure and performance changes in a strain of rat bred for hypertension (spontaneously hypertensive rat: SHR) in order to determine if high blood pressure might attenuate ETI. Although male SHRs experienced a severe ETI and a drop in blood pressure, much of the data is inconsistent with the hypothesis that hypotension causes performance decrements. In an additional series of studies, blood volume and serum chemistry data were analyzed. Male SHRs were significantly higher than normotensive controls on several blood chemistry determinations. Exposure to ionizing radiation, more often than not, enhanced these differences. These results could not be explained on the basis of radiogenic blood volume fluctuations.

Animals↗
PubMed1976

Biotin-binding protein from chicken egg yolk. Assay and relationship to egg-white avidin.

1. Biotin in chicken egg yolk is non-covalently bound to a specific protein that comprises 0.03% of the total yolk protein (0.8 mg/yolk). This biotin-binding protein is not detectable by the normal avidin assay owing to the biotin being tightly bound. Exchange of [14C]biotin for bound biotin at 65 degrees C is the basis of an assay for this protein. 2. Biotin-binding protein from egg yolk is distinguishable from egg-white avidin on Sephadex G-100 gel filtration, although the sizes of the two proteins appear quite similar. 3. Biotin-binding protein is denatured at a lower temperature and freely exchanges biotin at lower temperatures than does avidin. 4. The biotin-binding protein in egg yolk is postulated to be responsible for the deposition of biotin in egg yolk. D-[carboxyl-14C]Biotin injected into laying hens rapidly appears in the egg bound to yolk biotin-binding protein and avidin. Over 60% of the radioactivity is eventually deposited in eggs. The kinetics of biotin deposition in the egg suggests a 25 day half-life for an intracellular biotinyl-coenzyme pool in the laying hen.

Animals↗