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Biomedical subjects

R M Lauer

Publications and source records attributed to R M Lauer.

At least 37 records · Page 2Linked to original sources
PubMed1994

Cardiovascular health and disease in children: current status. A Special Writing Group from the Task Force on Children and Youth, American Heart Association.

More than 600,000 children in the United States have a congenital or acquired cardiac abnormality, and millions more are at risk of developing atherosclerotic disease in adulthood, a risk made particularly evident by the prevalence of cardiovascular risk factors in the young. There are barriers to optimum prevention and treatment of these conditions in children and youth. The AHA's Task Force on Children and Youth has described these barriers and outlined a series of recommendations and strategies to meet the challenges they impose. More research is needed, and research initiatives will be developed at scientific conferences designed to review critical areas of cardiac development and etiology of disease in children. Financial support for such research initiatives must be increased. Educational programs on cardiovascular risk factors will be extended to children and their families. When these programs are coordinated with efforts in the community and in schools, they will reduce the prevalence of cardiovascular risk factors. The task force recommends that various departments and committees of the AHA use their resources for the benefit of children: for example, by developing more research initiatives for funding by the AHA or NHLBI and increasing legislative and regulatory efforts in the areas such as mandatory school health programs and tobacco advertising. It is hoped that in the next decade, through research and educational efforts, many advances in the prevention and treatment of cardiovascular diseases in the young will be realized.

Cardiovascular Diseases↗
PubMed1994

Coronary risk factors in adolescents related to their knowledge of familial coronary heart disease and hypercholesterolemia: the Muscatine Study.

OBJECTIVE: To determine the utility of a school-based questionnaire, to identify adolescents with adverse coronary risk factor levels. DESIGN: In Muscatine, IA, students (9th through 12th grade) completed a questionnaire providing medical history information about first- and second-degree relatives. Anthropometric measures were obtained and blood pressure, lipid, lipoprotein, and apolipoprotein levels were determined. RESULTS: A history of parental coronary heart disease (CHD) was rare and a history of parental high cholesterol frequently was unknown; however, when known, a history of high cholesterol or early (30 to 55 years of age) or later (> 55 years of age) CHD (myocardial infarction, coronary bypass, or death from a heart attack) in grandfathers enriched the identification of adolescents with adverse coronary risk factors. Parental history of CHD was associated with an increased risk for high body mass index and low apolipoprotein A1 levels in their children. Grandfather history of early or later CHD was associated with an increased risk for low apolipoprotein A1 and high density lipoprotein cholesterol levels and high body mass index in their grandchildren. Students with positive grandfather histories of high cholesterol had higher total cholesterol, low density lipoprotein cholesterol, apolipoprotein B, and low density lipoprotein cholesterol to high density lipoprotein cholesterol ratios. Grandmother histories, because most were negative, did not help identify adolescents in this population with adverse coronary risk factors. CONCLUSIONS: A parental history of CHD as well as a grandfather history of high cholesterol or CHD enriches the identification of children with adverse coronary risk factor levels. The positive predictive values associated with using a school-based history obtained from adolescents, many with the aid of their parents, are small and many adolescents do not know their family history. It is essential that pediatricians inquire about parental and especially grandparental medical histories in accordance with the National Cholesterol Education Program guidelines to help identify children at highest familial risk. The importance of determining parental and grandparental histories of CHD or hypercholesterolemia should be emphasized to families who are uncertain of their histories to identify children and adolescents who require a physician's care. It is also important for pediatricians to remind their colleagues who care for patients with premature ischemic heart disease to refer their progeny for pediatric care so that their lipids and lipoproteins may be screened and counseling provided.

Adolescent↗
PubMed1993

Childhood predictors for high adult blood pressure. The Muscatine Study.

In adult populations, elevated blood pressure is related to the development of stroke, renal disease, and occlusive atherosclerosis. The significance of blood pressure levels in childhood, unless extremely elevated, has not been related to disease outcomes. In a study carried out in Muscatine, Iowa, the risk of high blood pressure in young adult life was evaluated based on the observations of blood pressure and other factors made during the school-aged years. Subjects, 2445 in number, were first observed at ages 7 through 18 years and again between 20 and 30 years. During childhood, measurements of blood pressure, height, and weight were made on alternate years. At adult ages, the same measurements were again made and a health questionnaire was administered. Adult blood pressure was correlated with childhood blood pressure, body size, and change in ponderosity from childhood to adult life. Adult ponderosity was related to childhood ponderosity, and those who were most obese as adults showed the greatest increase in weight from their childhood years. These observations suggest that strategies to prevent the acquisition of excess ponderosity during childhood may be useful in preventing adult hypertension.

Adolescent↗
PubMed1993

Genetic models of human obesity--family studies.

Childhood obesity is predictive of obesity as an adult, and individual differences in body weight relative to height (body mass index) in adults are important predictors of morbidity as well as mortality from atherosclerotic cardiovascular disease. The observation of strong familial correlations does not ensure that genes are involved in the determination of body mass index, because individuals in families share environments as well as genes. However, several recent studies have found evidence for both additive (polygene) and nonadditive (major gene) components. A question that results from these analyses is--what gene(s) has been inherited that carries an associated risk, most likely mediated by environmental exposures, for obesity? Studies to identify genetic loci linked to familial obesity should add to our understanding of the genetic factors involved in the determination of obesity and may lead to early identification of individuals and families at high risk for the chronic disorders that are associated with obesity.

Body Mass Index↗
PubMed1993

Does childhood obesity track into adulthood?

Between 1971 and 1981 the Muscatine Coronary Risk Factor Project measured, in six biennial school surveys, 2631 schoolchildren 9 to 18 years of age. Beginning in 1981, these individuals were measured near their 23rd, 28th, and 33rd birthday. This article examines the tracking from childhood into young adult years of the heights, weights, body mass indices (BMI), and triceps skinfold thicknesses (TSF) of these individuals. Depending on age and gender, tracking correlations for height ranged from 0.41 to 0.97; for weight they ranged from 0.51 to 0.88; for BMI they ranged from 0.58 to 0.91; and for TSF they ranged from 0.26 to 0.58. From 49 to 70% of children in the upper quintile of weight were found in the upper quintile of weight as adults, from 48 to 75% of children in the upper quintile of BMI were again in the upper quintile as adults, and from 25 to 56% of children in the upper quintile of TSF were again in the upper quintile as adults. These measures track from childhood into young adult life, and the majority of obese children become obese adults. However, about 31% of children from the upper quintile of BMI became adults with substantially lower levels, while a similar number of lean children become obese adults. Why some obese children become obese adults and others do not remains an unanswered question. The data presented herein indicate that obesity is often acquired during childhood and adolescence when preventive measures could be applied.

Adolescent↗
PubMed1993

Factors affecting left ventricular mass in childhood: the Muscatine Study.

OBJECTIVE: To examine the contribution of age, body size, and blood pressure to left ventricular mass (LVM) in childhood and develop a population-based reference of normative LVM data. METHODS: Age, sex, height, weight, and auscultatory systolic and diastolic blood pressures were measured and an echocardiogram was performed to estimate LVM in 904 normal children, aged 6 to 16 years, in Muscatine, IA. Pearson product-moment correlation coefficients were determined to describe the degree of linear association between LVM and age, body size, and blood pressure. Age-sex-, weight-sex-, and height-sex-specific Z scores were determined for LVM, age, weight, height, and blood pressure. Sex-specific LVM prediction equations were derived using weighted-least-squares regression analysis. RESULTS: A strong positive linear association of LVM with age, weight, height, Quetelet index, and systolic and diastolic blood pressure was demonstrated. Z scores for eight different LVM quintile patterns revealed that age, height, weight, and blood pressure each exert an independent influence on LVM in children. Sex-specific predicted M-mode LVM and upper limits of the 90% prediction intervals based on age and height are presented. CONCLUSION: Since age, height, weight, and blood pressure may each exert an independent influence on LVM in children, each factor must be considered when interpreting LVM in childhood. While age, sex, and height are unalterable, both weight and blood pressure can be modified. Thus the pathologic contribution of excess weight and blood pressure ought not be masked by statistical adjustments in reference values for LVM. Sex-specific values of LVM and the 90% and 95% prediction intervals of LVM that do not factor out the effects of obesity or blood pressure are presented. These provide the upper-limit reference values of LVM for the evaluation of children in whom increased LVM is suspected.

Adolescent↗
PubMed1992

Increased familial cardiovascular mortality in obese schoolchildren: the Muscatine Ponderosity Family Study.

Total and cause-specific mortality was investigated in 387 first- and second-degree deceased adult relatives of three groups of children selected from those who participated in three biennial school surveys in Muscatine, Iowa: the lean group (students in the first quintile of relative weight on all three surveys); the random group (a random sample of all eligible students); and the heavy group (students in the fifth quintile of relative weight on all three surveys). A greater proportion of death certificates for heavy group relatives listed a cardiovascular cause of death (60%) compared with lean (48%) and random (43%) group relatives. The relative risk of dying of cardiovascular disease for heavy group vs random group relatives was 1.41 (95% confidence interval 1.01, 1.98). In a subset of heavy group families identified by children with elevated systolic blood pressure, the proportion of death certificates listing a cardiovascular cause was even higher (76%) and the estimate of relative risk vs random group relatives was 2.20 (95% confidence interval 1.43, 3.37). These results indicate that persistent obesity in children, particularly when accompanied by persistent blood pressure elevation, identifies families whose members are at increased risk of dying of cardiovascular disease.

Adult↗
PubMed1991

Childhood predictors of high blood pressure.

Longitudinal studies in children have tracked blood pressure through childhood and from childhood into adult life. However, many children do not maintain their rank during these periods of observation. Several of the factors contributing to maintenance of rank order are reviewed, such as initial level of blood pressure, body size, sexual maturation, and family history of high blood pressure. Children with initially high level of blood pressure are more likely to become adults with high blood pressure, particularly if they are obese as children or become obese as young adults, and if they have a positive family history for hypertension.

Adolescent↗
PubMed1991

Factors affecting tracking of coronary heart disease risk factors in children. The Muscatine Study.

The public health implications of reducing or preventing the excess increase in blood pressure and the acquisition of obesity during childhood years are important. Many children with high blood pressure, particularly those who are initially obese or become obese as young adults and those with excess left ventricular mass for body size, become adults with high blood pressure. Although blood pressure and cholesterol have been shown to track during childhood and from childhood into the adult years, the use of repeated determinations along with measures of obesity and information concerning family history of diabetes and coronary heart disease can significantly add to the prediction of future elevated levels.

Adolescent↗
PubMed1991

Childhood predictors of future blood pressure.

Blood pressure in infants and children is much lower than that in adults. It is suspected that children whose blood pressures are greatest for their age or body size may be destined for future hypertension. However, it is apparent that some children with lower blood pressures are also destined for hypertension as adults. Children with a family history of hypertension demonstrate greater blood pressure and heart rate responses to mental challenge. These responses are enhanced when a high salt diet is consumed. Increased maximal exercise systolic blood pressure and increased left ventricular wall mass in childhood add significantly to the prediction of future high blood pressure. In addition, the acquisition of excess weight for height from childhood to young adult life adds to the prediction of future blood pressure elevations. Both children and adults who are obese have significantly higher blood pressures than those who are lean. Approximately 34% of the variability in body mass index is explained by genotype differences at a single recessive locus, 41% by genotype differences at polygenic loci, and 25% by nongenetic factors. Thus, the genetic influence of obesity may be an important factor responsible for elevated blood pressure in both children and adults.

Adult↗
PubMed1991

The genetic and environmental sources of body mass index variability: the Muscatine Ponderosity Family Study.

The role of genetic and environmental factors in determining the variability in body mass index (BMI; kg/m2) was investigated in 1,302 relatives identified through 284 schoolchildren from Muscatine, IA. BMI levels were first adjusted for variability in age, by gender and by relative type. There was significant familial aggregation of adjusted BMI in the pedigrees, as indicated by inter- and intraclass correlation coefficients significantly different from zero. A mixture of two normal distributions fit the adjusted BMI data better than did a single normal distribution. Genetic and environmental models that could explain both the familial aggregation and the mixture of normal distributions were investigated using complex segregation analysis. There was strong support for a single recessive locus with a major effect that accounted for almost 35% of the adjusted variation in BMI. Polygenic loci accounted for an additional 42% of the variation. Approximately 23% of the adjusted variation was not explained by genetic factors. For spouses living in the same household, their shared environment accounted for 12% of their variation. For siblings living in the same household, their shared environment accounted for 10% of their variation. While shared environments contributed to variation in adjusted BMI, more than 75% of the variation was explained by genetic factors that include a single recessive locus. Approximately 6% of the individuals in the population from which these pedigrees were sampled are predicted to have two copies of the recessive gene, while 37% of the individuals are predicted to have one copy of the gene.

Adolescent↗
PubMed1991

Children and cholesterol: potential prevention for future good health.

The prevention of cardiovascular disease beginning in childhood may be affected with two strategies. The first is a population approach to lower the cholesterol levels in all American children. The second is an individualized strategy to identify and treat children at particularly high risk in the health care system.

Adolescent↗
PubMed1990

Use of cholesterol measurements in childhood for the prediction of adult hypercholesterolemia. The Muscatine Study.

This article describes the validity and utility of screening tests for total cholesterol levels in school-age children to predict those who, when adults, will have cholesterol levels that the National Cholesterol Education Program suggests need continuing surveillance and intervention. Two thousand three hundred sixty-seven children aged 8 to 18 years were examined on several occasions and were followed up to ages 20 to 30 years. Of children with cholesterol concentrations exceeding the 75th percentile on two occasions, 75% of girls and 56% of boys would not qualify for intervention as adults by the National Cholesterol Education Program criteria. Of children with cholesterol levels exceeding the 90th percentile on two occasions, 57% of girls and 30% of boys would not qualify for intervention as adults. Because the efficacy, safety, acceptability, and cost of treatment for high cholesterol concentrations in childhood is evolving, the need for universal screening of childhood cholesterol levels must be considered carefully in view of the number of children with high levels of cholesterol who, as adults, do not meet the criteria for intervention suggested by the National Cholesterol Education Program.

Adolescent↗
PubMed1990

Risk factors for adolescent cigarette smoking. The Muscatine study.

Smoking among adolescents is a developmental phenomenon with several factors exerting an influence on cigarette use at different times. We examined the longitudinal influences of several behavioral and social variables on the smoking status of 443 students followed from early to late adolescence. Of the factors examined, association with friends who smoke and previous smoking status were consistently associated with an adolescent's future smoking status. Other factors, such as attachment to father or to mother, parental supervision, extracurricular activity, perceived negative and positive effects of smoking, and academic involvement, were all related to late adolescent smoking status. These observations suggest that strategies that influence smoking behavior need to be directed not only to the individual child but also to influences within the child's home and school environment.

Adolescent↗