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Biomedical subjects

J A Morrison

Publications and source records attributed to J A Morrison.

At least 109 records · Page 6Linked to original sources
PubMed1980

Lipids and lipoproteins in 13--18-year-old Venezuelan and American school children. Within- and cross-cultural comparisons.

Plasma lipids, lipoproteins, and anthropometric measurements were assessed in 996 Venezuelan school children (ages 13--18 years) (441 in private, 555 in public schools, Merida, Venezuela) with cross-cultural comparisons to 419 13--18-year-old American school children from suburban Cincinnati, Ohio. Although there were no systematic differences in plasma cholesterol and triglyceride between public and private Venezuelan school children, low density lipoprotein cholesterol (LDL-C) levels were higher and high density lipoprotein cholesterol (HDL-C) levels lower in public than private school children. Within Venezuelan schools, and between sex, female children had consistently higher total plasma cholesterol, marginally higher HDL-C, and appreciably higher LDL-C than males. There were no consistent cross-sectional changes in lipids and lipoproteins in Venezuelan school children with age. Within sex, cross-cultural comparisons with Cincinnati school children revealed 2 major, consistent differences; Venezuelan children had higher fasting plasma triglyceride and lower HDL-C levels, not attributable to systematic differences in Quetelet index, laboratory methodology, subject selection, or sampling technique. Total plasma cholesterol and HDL-C were similar for Venezuelan and Cincinnati school children. Maintenance of comparable LDL-C but lower HDL-C levels by Venezuelan children into adulthood might, speculatively, be associated with augmented risk for coronary heart disease.

Adolescent↗
PubMed1980

Interrelationships of lipids, lipoproteins, and clinical chemistry measurements in 1605 schoolchildren, ages 6-17: the Princeton Schoolchildren Study.

Interrelationships between clinical chemistry tests (hepatic, renal, and endocrine systems) and lipids-lipoproteins were assessed in 1605 schoolchildren ages 6-17; 916 were randomly selected and 689 selected because of hypercholesterolemia/hypertriglyceridemia from the Cincinnati Lipid Research Clinic's Princeton School study. The clinical chemistry measurements most consistently and uniformly rated to lipids and lipoproteins were plasma glucose (GLU), uric acid (UA), serum glutamic oxaloacetic transaminase (SGOT) and hematocrit (HEMO). These relationships were similar quantitatively and qualitatively in 6-11-yr-old and 12-17-yr-old children in both the random and the hyperlipidemic recall groups. The most consistent relationship was a positive one between glucose and triglyceride (TG) and very low density lipoprotein cholesterol (C-VLDL). A second, highly consistent, relationship pattern included an inverse correlation between serum UA and high density lipoprotein cholesterol (C-HDL)), and a positive UA-C-VLDL relationship; both were seen in 12-17-yr-old children. Hematocrit was positively associated with TG; SGOT was positively associated with total cholesterol and C-HDL. Many of these relationships, particularly those for plasma GLU and UA, presage relationships observed in normal and hyperlipoproteinemic adults, and may allow a better understanding of the physiology and pathophysiology of lipid and lipoprotein levels.

Adolescent↗
PubMed1980

Nutrient intake: relationships with lipids and lipoproteins in 6--19-year-old children--the Princeton School District study.

Relationships between nutrient intakes and plasma lipids and lipoproteins were studied in 949 randomly selected children, ages 6--19, in the biracial, suburban, Princeton School District. While nutrient intake increased with age in males, such age-associated increases in nutrient ingestion were much less consistent or were not significant for females. Primarily in the 6--9 and 10--12 yr age groups, white children ingested more total calories, more saturated fat, and a lower ratio of polyunsaturated to saturated (P/S) fat, more total carbohydrates, sucrose, starch, and other carbohydrates, and more protein than black children. After adjusting for age, race, sex, weight, and height, several nutrient-lipid and lipoprotein partial correlation coefficients were significant, but of relatively low magnitude. There were weak but significant inverse correlations between dietary P/S ratios and dietary carbohydrates with both total (r = -.07, -0.7) and low-density lipoprotein cholesterol (C-LDL), (r = -.07, -.08). Plasma high-density lipoprotein cholesterol (C-HDL) was inversely and significantly correlated with dietary sucrose (r = -.07); plasma triglyceride correlated positively with dietary sucrose (r = .08). Potential relationships between nutrients and lipids-lipoproteins were also examined in children at the extremes of, and in the middle of, lipid-lipoprotein distributions. After covariance adjustment for age, sex, race, and Quetelet index, children having the highest levels of C-HDL had the lowest intake of dietary carbohydrate and total calories. After further covariance adjustment for total calories, children at the highest end of the plasma cholesterol distribution had a greater intake of cholesterol and total protein than did children in the lowest end of the distribution. Nutrient intake may play a small but significant role relative to lipids and lipoproteins in children, and as such, may have importance relative to pediatric precursors of atherosclerosis.

Adolescent↗
PubMed1980

Parent-child nutrient intake interrelationships in school children ages 6 to 19: the Princeton School District Study.

Interrelationships between nutrient intakes (dietary cholesterol, total carbohydrate, saturated and polyunsaturated fat, and total calories) of parents and children were examined in 294 families (60 black, 234 white) which included at least one parent and one child in the Princeton School survey of parents and their children, ages 6 to 19. The nutrient data were collected by means of the standardized Lipid Research Clinics' collaborative 24-hr dietary recall; simple correlations and analysis of covariance were used to assess parent-child nutrient intake (per kg body weight) relationships. There were significant positive simple correlations between nutrient intake of parents and children for total carbohydrate (r = 0.28, P < 0.0001), saturated fat (r = 0.15, P < 0.01), polyunsaturated fat (r = 0.19, P < 0.001), and calories (r = 0.24, P < 0.0001); parents' intake of cholesterol did not correlate with that of their children (r = 0.004, P > 0.1). By analysis of covariance with adjustment for sex, race, age, and recall group, the parent-child association of cholesterol intake was significant (P = 0.001), and the remaining parent-child nutrient intake relationships were congruent with those observed by simple correlations. The proportion of variation of the children's nutrient intake accounted for by parental nutrient intake varied from a low of 23% for parent-child cholesterol intakes (all parents-all children) to a high of 97% for carbohydrate intake in black fathers over age 40 and their children. The multiple Rs2 for black parents-black children for nutrient intakes were higher than those for white parents-white children for carbohydrate, saturated fat, and calories. Close parent child nutrient interrelationships not only suggest that a considerable portion of lipid-lipoprotein variability may be nutritionally-environmentally determined, but may contribute to clustering of coronary heart disease risk factors in families.

Adolescent↗
PubMed1980

Clinical chemistry determinations for a biracial cohort of 1,605 normal and hyperlipidemic schoolchildren aged 6 to 17.

Distributions of nine clinical chemistry determinations (serum bilirubin, globulin, creatinine, thyroxine, alkaline phosphatase, hematocrit, aspartate aminotransferase, uric acid, and plasma glucose) were assessed for 1,605 schoolchildren aged 6 to 17 years, in the Cincinati Lipid Research Clinic's Princeton School District study. Nine hundred and sixteen children were randomly recalled, and 689 were recalled by virtue of elevated (top decile) plasma cholesterol or triglyceride or both. For each clinical chemistry measurement, the following factors were considered: random and hyperlipidemic recall groups, age, sex, and race. The data were arrayed to provide the fifth percentile, the median, and the ninety-fifth percentile levels, as well as the 90% confidence interval of about the fifth and ninety-fifth percentile estimates. These data allow black-white age and sex, and normal-hyperlipidemic comparisons of commonly measured clinical chemistry determinations among a large population of children. This study also provides, for the methods used, accurate estimations of age-, sex-, race-, and recall group-specific percentile distributions for selected clinical chemistry determinations for children.

Adolescent↗
PubMed1980

Studies of blood pressure in schoolchildren (ages 6--19) and their parents in an integrated suburban school district.

Systolic blood pressure (SBP) and diastolic blood pressure (DBP), along with demographic and anthropometric variables were assessed in a biracial group of schoolchildren and parents in an integrated suburban school district: 682 schoolchildren, ages 6--19, including 268 white males, 236 white females, 85 black males and 93 black females; 362 adults, ages 20--64, including 142 white males, 159 white females, 20 black males and 41 black females. There were no significant black-white SBP or DBP differences in children, while SBP and DBP were higher in adult blacks than whites. Using multiple regression analysis, with BP as the dependent variable, SBP in children was significantly associated with pulse, weight, skinfold thickness, age and height; DBP was significantly associated with age, pulse, weight, and skinfold thickness. Race, sex, and education of the head of household did not significantly enter the multiple regression matrix for children's BP. Respectively, 29% and 22% of the variance of the children's SBP and DBP was accounted for by the measured variables. In adults, SBP was significantly related to weight, race, pulse, and age; DBP was significantly related to weight, race, age, and skinfold thickness. Respectively, 27% and 24% of the variance of the adults' SBP and DBP was accounted for by the measured variables. Covariance adjusted mean SBP and DBP were higher in hypertriglyceridemic than in hypotriglyceridemic children (p = 0.001), and were lower in hyperalpha-lipoproteinemic than hypoalpha-lipoproteinemic children (p less than or equal to 0.03). Children in an integrated school district may have shared behaviors, goals, and environments contributing to shared BP, while differing environmental factors may become amplified with age and life experience and contribute to higher BP in black adults.

Adolescent↗
PubMed1980

Relationships of measurements of body mass to plasma lipoproteins in schoolchildren and adults.

This report focuses upon relationships of body mass indices to plasma lipids and lipoproteins in 1682 children (ages 4--20 years) and 876 of their parents (ages 21--66 years) sampled during the Cincinnati Lipid Research Clinic's Princeton School District population study, 1973--1975. After an initial sampling of the schoolchildren, two subsets were then recalled, a 15% random sample independent of lipid levels (the random recall group), and a second group, approximately 10% dependent upon lipid levels (the hyperlipidemic recall group). There were no consistent patterns of difference for Quetelet indices and triceps skinfold measurements between black and white children. Hyperlipidemic recall children had higher mean Quetelet indices than random recall children. In children and adults, from both random and hyperlipidemic recall groups, Quetelet index was inversely related to high density lipoprotein cholesterol (C-HDL) and positively related to low density lipoprotein cholesterol (C-LDL), very low density lipoprotein cholesterol (C-VLDL), and triglyceride. The relationship (partial correlation) between Quetelet index and plasma lipoproteins was highly significant after adjusting for age, race, sex, skinfold thickness, cigarette smoking, alcohol intake, and oral contraceptive intake. In the random and hyperlipidemic recall groups of children, the amounts of variation of C-HDL accounted for by the explanatory variables (as above) were 8% and 18%, respectively, for C-LDL 4% and 7.4%, for C-VLDL 7.2% and 14.4%, and for triglyceride 10.7% and 16.3%. In the random and hyperlipidemic groups of children, the additional amounts of variation of C-HDL accounted for by the addition of Quetelet index to the explanatory variables were 3% and 4.7%, respectively, for C-LDL 3.1% and 1.8%, for C-VLDL 4.2% and 2.4%, and for triglyceride 5.5% and 3.3%. Measures of relative body mass are inversely associated with C-HDL. Although factors which control ponderosity and C-HDL may be independent, and weight loss or gain may not significantly alter C-HDL levels, it is speculated that attempts to maintain ideal body weight or reduce toward ideal body weight may maximize the levels of the anti-atherogenic C-HDL.

Adolescent↗
PubMed1980

Clustering and interrelationships of coronary heart disease risk factors in schoolchildren, ages 6-19.

Clustering and interrelationships of common and easily identifiable risk factors in 951 children (ages 6-19) from the Cincinnati Lipid Research Clinic's Princeton School of District Study were assessed. Several patterns of partial correlation coeffieients appeared after multiple regression analysis with adjustment for age, sex, Quetelet index, and race. Systolic blood pressure (SBP) was positively correlated with plasma cholesterol and triglyceride, and with saturated fat intake. Plasma high density lipoprotein cholesterol (C-HDL) was positively associated with occupation of the head of the household and inversely associated with cigarette smoking and sucrose intake. Using multiple regression equations, from 29-41% of the variance for SBP and diastolic blood pressure (DBP) could be explained by the measured variables, with age, skinfold thickness, Quetelet, occupation, and education of the head of the household recurrently appearing in the regression equatons. Low density lipoprotein cholesterol (C-HDL) was the variable for which the lowest amount of variance could be explained in the four race-sex groups. Discriminant function analysis allowed an assessment of interrelationships of C-LDL-C-HDL aggregate groups to other risk factor mean residuals. The variables which contributed significantly to the discrimination between lipoprotein groups were Quetelet index, skinfold thickness, and DBP. Children in the highest C-LHL-lowest C-HDL quintile group had by far the highest residual Quetelet index and skinfold thickness, along with above average SBP, while those in The lowest C-LDL-highest C-HDL quintile group had the lowest residual Quetelet index, skinfold thickness, and SBP. Common risk and anti-risk factors for coronary heart disease (CHD) in children cluster, allowing identification of groups of children putatively at relatively high and low CHD risk as adults.

Adolescent↗
PubMed1980

Familial hyper-alpha-lipoproteinemia in 26 kindreds.

The inheritance of familial hyper-alpha-lipoproteinemia was investigated in 161 individuals in 11 black kindreds and 15 white kindreds. After age and sex adjustment, the distribution of high density lipoprotein-cholesterol (C-HDL) in the relatives of probands was examined for evidence of bimodality. In whites, bimodality appeared to be present, with one mode at about 46 mg/dl and the other at about 69 mg/dl. In blacks, there was little convincing evidence of bimodality. In the white kindreds, it appeared that one factor with a relatively large effect is causing the familial aggregation of high C-HDL levels; this factor could be a major gene.

Adolescent↗
PubMed1980

Intrafamilial associations of cholesterol and triglyceride among related and unrelated household members.

The purpose of this report was to assess intrafamilial associations of lipids between related and unrelated household members seen in the course of a population-based survey of lipids in schoolchildren and their parents. Fasting plasma total cholesterol and triglyceride levels were measured in 6,857 and 3,079 adults. Age effects were removed for each sex-race group using a third-degree polynomial regression of lipid on age; the residuals were then used as observations in the analyses. For both cholesterol and triglyceride, significant positive correlations existed between father and son, father and daughter, mother and son, and mother and daughter. For both cholesterol and triglyceride, although the mother-child correlations were stronger than those for father-child, they were not significantly different. There were no significant correlations between step, foster, or adoptive parents and children. For cholesterol in sibships of size two, intrasibship correlations for fully related siblings were 0.333, for half-sibs 0.164, and for unrelated sibs, 0.085. Consistently closer intrafamilial cholesterol and triglyceride associations between related than unrelated family members, and the strong parental effects on cholesterol and triglyceride indicate, in aggregate, that a considerable proportion of the variation of cholesterol and triglyceride can be explained by genetic factors.

Adult↗
PubMed1980

Lipids and lipoproteins in Venezuelan and American schoolchildren: within and cross-cultural comparisons.

This study was designed to focus upon within-culture differences in plasma lipids and lipoproteins in Venezuelan schoolchildren having different socioeconomic and nutritional backgrounds and also to provide cross-cultural comparisons of lipids, lipoproteins, and anthropometric measurements between Venezuelan and American schoolchildren. The study was carried out in 1298 schoolchildren, ages 7 to 12 years, 428 in private and 870 in public schools in Merida, Venezuela, with comparison to 472 public schoolchildren in the (Cincinnati, OH) Princeton School District. Within Venezuelan schools, private shcoolchildren were heavier, taller, had marginally higher Quetelet indices, and had considerably higher fasting plasma cholesterol, plasma high-density lipoprotein (C-HDL), and plasma low-density lipoprotein (C-LDL) levels. These lipid-lipoprotein differences were highly significant after adjusting (by covariance analysis) for Quetelet index, sex, and age. Children from private Venezuelan schools ingested more total calories, more protein, more fat, and more carbohydrate. When the diet compositions were calculated as percentage of total calories, the private schoolchildren ingested nearly twice as many calories as fat and a somewhat lower proportion of calories as carbohydrate, with a comparable proportion as protein, when compared to the public Venezuelan schoolchildren. Male-female comparisons within Venezuelan schools revealed patterns of sex-related lipoprotein differences which were qualitatively similar to those in Princeton schoolchildren. Thus, 7- to 12-year-old females had higher total plasma cholesterol and triglyceride, lower C-HDL, and higher C-LDL. Within sex, cross-cultural comparisons of lipids, lipoproteins, and Quetelet indices revealed two major differences. Venezuelan children had significantly higher fasting plasma triglyceride and lower C-HDL levels, differences not attributable to systematic differences in measures of ponderosity, because Quetelet indices in Venezuelan and Cincinnati schoolchildren did not differ appreciably. In regard to total and low-density lipoprotein cholesterol, Venezuelan and Princeton public schoolchildren were remarkably comparable, although Venezuelan private schoolchildren had somewhat higher plasma cholesterol and C-LDL levels than did Princeton public schoolchildren. We speculate that increasing "westernization" and "urbanization" of Venezuelan society is associated with convergence of Venezuelan and American pediatric plasma lipid and lipoprotein levels. Maintenance of comparable total plasma cholesterol and C-LDL levels with lower C-HDL into adulthood in Venezuela would, in fact, suggest augmented risks for coronary heart disease for Venezuela within this lipid-lipoprotein frame of reference.

Age Factors↗
PubMed1980

Hyperalphalipoproteinemia in hypercholesterolemic adults and children.

This report was designed to describe and characterize the proportion of of hypercholesterolemic children and adults in the Lipid Research Clinics collaborative prevalence study whose elevated total plasma cholesterol levels were accounted for by elevated high density lipoprotein cholesterol (C-HDL), not by elevated levels of low density lipoprotein cholesterol (C-LDL). In randomly recalled 6-19 year old children having age-, race-, an sex-specific plasma cholesterol levels greater than or equal to 95th percentile levels, 22% of white males, 22% of white females, and 44% of black males had C-HDL, but not C-LDL greater than or equal to age-, sex-, and race-specific 95th percentile levels. In contrast, for adults (ages 20-79 years), 3% of white males, 10% of white females, 17% of black males, and 25% of black females had predominant hyperalphalipoproteinemia which accounted for their hypercholesterolemia. In participants defined as hypercholesterolemic on the basis of two examinations it was observed that the majority of children and adults were in the C-LDL elevated and C-HDL not elevated category. Hypercholesterolemic adults were not as likely as the hypercholesterolemic children to be in the C-HDL elevated and C-LDL not elevated category. For both children and adults, blacks were more likely to have predominant hyperalphalipoproteinemia accounting for their elevated total plasma cholesterol levels than were whites. For hyperalphalipoproteinemic, hypercholesterolemic children and adults, the mean ratio of C-LDL to C-HDL ranged from 1.3 to 1.4 (in children) and 1.4 to 2.1 (in adults), levels well below the overall mean ratio for the entire Lipid Research Clinics random recall group of 2.7 for children and 4.2 for adults. An understanding of the multiple etiologies of hyperalphalipoproteinemic-hypercholesterolemics may be useful in considering programs designed to elevate C-HDL over time, with an aim at reducing CHD risk.

Adolescent↗