Search

Studies of the pathobiologic consequences of high blood pressure in childhood, as well as those following blood pressure levels into young adulthood, indicate that early intervention in the natural history of essential hypertension is warranted. In an exploratory study of the concept, 95 children out of 1604 (aged 8 to 18 years), who persistently scored higher than the 90th percentile for blood pressure over a 4-month period, considering the race, sex, and height of the children, were studied. Five series of replicate measurements with 30 total observations were obtained. Children with evidence of secondary hypertension were excluded. The study children were randomly divided into treatment (n = 48) and high-comparison (n = 47) groups. Treatment consisted of low-dose combined drug therapy (propranolol and chlorthalidone) with an educational program directed towards hypertension and dietary and exercise modification. Monthly follow-up was continued for 30 months. Significant systolic (-3.59 mm Hg) and diastolic (-1.73 mm Hg) changes were noted up to 30 months (p less than 0.05) with minimal side effects. Furthermore, analyses suggested that the blood pressure change, at least in the first month, was mostly attributable to drug therapy. Moreover, the mechanism of blood pressure change appeared to be race-specific, with whites having pulse rate changes and blacks having significant weight changes, which were associated with blood pressure change. This trial shows further research is warranted to determine optimum approaches for early treatment of essential hypertension to prevent future hypertensive disease.

Children initially aged 21/2 to 14 years living in Bogalusa, Louisiana (n = 2530) were examined twice, 3 years apart, for fasting serum pre-beta- and beta-lipoprotein cholesterol (beta-LPC) levels. Based on averages of these levels, the children were ranked for pre-beta- and beta-LPC in combinations of extreme quintiles (low-low, high-high) or quartiles (low-high, high-low), n = 388, and were reexamined for serum lipids, lipoprotein cholesterol, glucose tolerance, and anthropometry. Skinfolds were thicker in whites than in blacks except for subscapular skinfold. Children in the high-high stratum were heavier and more obese. The postglucose insulin level was positively correlated with fasting serum triglycerides and pre-beta-LPC. Compared with other strata, high-high strata showed more clustering among half-hour and 1-hour plasma insulin, serum triglycerides and pre-beta-LPC, and trunk skinfolds. We conclude that racial differences in lipid and carbohydrate metabolism occur in all four strata, and that a strong clustering occurs more in the high-high stratum, which may, in part, explain the coincidence of several high cardiovascular risk factor levels observed in the same children. These observations document in free-living children changes of obesity, plasma glucose, and insulin metabolism related to serum lipoproteins that are involved in the early natural history of atherosclerosis.

We explored the relation between amount of adipose tissue and maturation in 3,524 boys and girls ages 5–14 years examined in 1973–1974, and 4,074 children ages 5–17 years (re)examined in 1976–1977. Subjects were drawn from a total, geographically defined, biracial community as part of a cardiovascular risk factor screening. Height, weight, triceps skinfold thickness, external sexual maturation according to Reynolds—Tanner, status of menarche, and visible gynecomastia were assessed. We observed that adiposity was positively correlated with acceleration of maturation. This positive correlation was stronger in girls than boys, and stronger in whites than blacks. Visible gynecomastia was more prevalent at ages 13–15 years than other ages. These boys were markedly more obese than all others. Gynecomastia was negatively associated with sexual maturation (after controlling for the positive effect of adiposity), in white boys more than in black. Adiposity may have some feedback sex-hormonal effect, in girls more directly, toward accelerated maturation. In boys adiposity enhances gynecomastia which in turn is likely related to a deceleration in male maturation. The observed effects of adiposity on sex-hormonal function could have implications for the known association between adiposity and incidence of sex hormone-related female cancers, especially mammary cancer.

A model designed as primary hypertension prevention for children ranking high in blood pressure, selected from a total population, was applied to a semirural, biracial community. A Dietary/Exercise Alteration Program Trial (ADAPT), in combination with low-dose medication, was tested on 48 children aged 8-18 years who were randomly selected from 100 children consistently in the upper blood pressure decile. The interactive model a) focuses on a major public health problem that is measurable and modifiable, b) outlines a preventive approach to involve children and parents in establishing healthy life styles, and c) converts community limitations into resources. The comprehensive program was developed to support eating and exercise modifications accepted for hypertension treatment without placing children in a sick role. Sodium reduction, weight control, and regular exercise are the life-style changes promoted. Indicators for evaluating development and implementation of ADAPT are presented. The commitment to written pledges, ie, making simple behavioral changes, had a significant inverse association with post-treatment sodium and energy intakes in regression models that included the child's curriculum and physical activity class attendance. ADAPT represents an initial approach for developing primary preventive treatment of early essential hypertension in a pediatric population.

The association of heart-related mortality with tissue cadmium and lead in a study of autopsies performed on persons who resided in a soft-water, leached-soil area of North Carolina was examined. Liver cadmium concentrations and aortic lead level were indices of these elements. Both cadmium and lead levels had statistically significant correlations with cause of death (heart-related disease vs. non-heart-related disease, excluding cancer). Although cause of death was significantly associated with age, the association with cadmium and lead persisted after statistical adjustment for the effect of age. The combined effects of cadmium and lead provided sufficient information in an additive model to predict cause of death correctly for 80% of the cases, with age contributing insignificantly. These findings indicate the intimate relation of these two trace metals with increased risk of heart-related mortality, even in light of known conventional causes of such deaths.

Blood pressure, height, weight, maturation, triceps skinfold thickness, serum lipids, and hemoglobin were measured as risk factors for coronary artery disease in 3,524 children (93% of the eligible population) in Bogalusa, Louisiana. Nine blood pressures were taken on each child by trained observers with mercury sphygmomanometers (Baumanometer) and Physiometrics automatic recorders in a rigid randomized design in a relaxed atmosphere with other children present. The pressures observed were low compared to reported data. Black children had significantly higher blood pressures than white children. This difference, starting before age 10, was largest in the children in the upper five percent of the pressure ranks. Stepwise multiple regression analysis revealed that this racial differnce was significant when measured by an automatic recorder. Body size, expressed by height and by weight/height3 index, was a strong determinant of blood pressure level. Other positive determinants were blood hemoglobin and external maturation.

Cancer mortality is high among white men residing in southern Louisiana parishes (counties). In an effort to elucidate this phenomenon, we studied three environmental correlates of cancer-namely, smoking, residence in urban communities, and residence in the wetlands. Multiple regression analysis was applied to cancer mortalities adjusted for age and urban residency, and specific for race, sex, amount of standing water area in the parish, and cancer site. Cancer sites were grouped according to their correlation with smoking: strong, moderate, and no correlation. For men, the smoking-related cancer mortality not only showed an association with residence in wetlands but also was higher in the Louisiana wetlands than in the remainder of the United States.

The onset of essential hypertension early in life is indicated by the high tracking of blood pressure during adolescence; intervention in adults with mild hypertension has been found successful. How, then, can high blood pressure levels in children be modified to prevent early hypertensive cardiovascular disease in adulthood? In an entire biracial town (population 9000) we surveyed 1604 (89%) of all children aged 8--18 years for blood pressure and reexamined those in the upper decile of mean blood pressure (for each race, sex, and height) on three additional occasions. On each examination nine blood pressures were taken by trained observers. All children consistently in the top decile were randomly allocated into either a treatment (n = 50) or comparison (n = 50) group. These two groups and an additional midrange blood pressure comparison group (n = 50) were followed regularly using school facilities including community and school programs. Treatment consisted of 1) dietary guidance; 2) modifications of school lunches and snacks with healthy substitutes; 3) parental involvement; 4) a low dose diuretic and beta-antagonist given by usual standards. All study groups were monitored for blood pressure in a blind manner. In 6 months of observation, blood pressure in the treatment group remained 5 and 3 mm Hg (systolic and diastolic) less than controls (p less than 0.001 and p less than 0.01). An orchestrated community-wide attack on early-stage hypertension is feasible and seems to offer exciting potential for prevention of early hypertensive disease.

A special in-depth substudy was conducted on 388 children from a total biracial (black-white) population, who were stratified on levels of serum beta- and pre-beta-lipoprotein cholesterol to explore factors associated with lipoprotein levels in childhood. Biochemical parameters on venous blood samples were obtained both on fasting subjects and after an abbreviated glucose tolerance test, along with selected anthropometric measures like height, weight, and skinfolds. Biochemical and anthropometric relationships were minimal for children with elevated beta-lipoprotein cholesterol and low pre-beta-lipoprotein cholesterol. On the other hand, children with higher levels of pre-beta-lipoprotein cholesterol, with or without elevated beta-lipoprotein cholesterol, showed associations with fatness and slightly higher levels of glucose and insulin, with other biochemical parameters considered within normal levels. These differences noted among free-living children with different levels of serum lipoproteins provide clues to mechanisms involved in the early natural history of coronary artery disease.

Body height and body mass as determinants of basal blood pressure in children--The Bogalusa Heart Study. Am J Epidemiol 106:101-108, 1977. Risk factor variables for coronary artery disease were measured in a total biracial community study of 3524 children, ages 5-14 years. Anthropometric variables, serum lipids, and blood pressure (BP) were measured in a rigid randomized design. Blood pressure data were obtained with an automatic recording instrument that avoids excessive pressure readings in obese children by the use of an over-sized arm cuff bladder with a built-in infrasonic transducer. By reducing the anxiety of the child and by taking multiple readings, pressures were obtained that approached published basal levels. A multiple regression analysis showed that all measured variables could account for 39% of the systolic BP variation. Major determinants were based on weight (W) and height (H). The BP levels, when related to H and to a weight-height index (W/H3), suggest a strong influence of H and an additional influence of W/H3 on BP, both consistent and proportionate over the entire ranges of H and W/H3. The total spectrum of observed correlates of BP, resulting from the multiple regression analysis, suggests that the BP measured under basallike conditions increases as the child grows and is proportional to lean body mass and total body mass. Practical criteria for evaluating abnormal blood pressure levels in children should be based on normative values derived from body weight and body height rather than from age.

Eighty per cent of all identified children 2 1/2-5 1/2 years old in a total geographic community in Bogalusa, Louisiana, were examined for cardiovascular disease risk factor variables, including blood pressure (BP), anthropometric measurements, and blood lipids. Blood pressure was measured by three instrument types, each with three readings, according to a rigid, randomized design. Results from the three instruments were compared, and potential biases for each instrument are listed. All observations on the children were analyzed by multiple regression with BP as the dependent variable. After controlling for the mood of the child, the authors found that some index of body size was positively related to BP, whereas age, race, and serum lipids were not consistently related. The regressions of blood pressure on height as well as on log weight fit straight lines. These results conform with the findings for the 5- to 14-year-olds in this community. The basal or fundamental reference blood pressure is likely to rise gradually from birth to the age of incipient adult stature, and to be linearly related to height and to log weight. Changes observed over time are needed to relate BP levels in childhood to the early natural history of essential hypertension.

Although differences in hemoglobin levels between blacks and whites may be due in part to genetic influences, low hemoglobin levels in black girls of childbearing age may nevertheless constitute a health hazard. To study this problem, hemoglobin levels were examined in children of a biracial community not only before but also during and after puberty and menarche. At the same time, 24-hour dietary recalls of a representative group of 13-year-olds in the same population were examined with respect to the intake of iron and nutrients influencing iron absorption. In black girls, hemoglobin levels dropped after menarche, accompanied by a diet marginal in iron and in iron-absorption-promoting nutrients. Questions as to hemoglobin levels compatible with optimum health remain, and racial differences and genetic influences on levels should not be an excuse for failure to address this problem. More investigational studies are also needed to observe responses to an optimum dietary iron intake.

Geographical differences in cardiovascular mortality within the United States have not yet been adequately explained. Age-adjusted rates of mortality due to arteriosclerotic heart disease in the white residents of 99 of the 100 largest cities in the United States were compared with the hardness of the finished drinking water of the municipal supplies and with the altitude of residence above sea level. This mortality showed a higher negative correlation with the latter variable than with the former for white residents. These findings are coherent with results from other epidemiological studies showing decreased cardiovascular disease mortality at high altitude. Animal experiments and pathological observations in the literature make it likely that hypoxia causes an increase of collateral circulation in the coronary arteries. However, alternative explanations of the presently observed relationship have not been excluded by our study.

The relationship of dietary K+ with Na+ balance in young normotensives was studied. A, In two biracial communities, all children with specified age were stratified by blood pressure level. Children from selected strata collected 24-h urines on ambulatory basis and provided fasting blood for electrolytes and creatinine determination. For the upper percentile ranks (n = 160), the Na+ and K+ clearances correlated closer in Blacks than whites (r = 0.7 versus r = 0.4, p less than 0.005 for difference). B, To test for a causal effect of K+ intake on Na+ excretion, six white and eight Black young healthy normotensive volunteers took 80 mEq KCl daily in addition to their usual diets. They collected 24-h ambulatory urine and stool samples for 3 base-line days, and 4 days during K+ supplementation. Na+ and K+ intake was monitored daily. Upon K+ supplementation, Blacks showed natriuresis (p less than 0.01), negative Na+ balance (p less than 0.05), and a cumulative K+ balance more positive than whites (p less than 0.0001 versus p less than 0.05). Dietary K+ enrichment could affect Na+ balance.

An epidemiological survey of anthropometric and maturation variables was conducted on 3,524 children from the biracial community of Bogalusa, Louisiana. These children, representing 93% of the population, were examined during the school year September 1973 through May 1974. Black boys differed slightly from white boys in height and weight; black girls were taller and heavier than white girls. The black children had longer upper arm lengths and smaller upper arm circumferences than the white children. The median ponderosity (weight divided by the cubed height) decreased with increasing heigth for the four race-sex groups, and a skewed distribution of ponderosity indicated an excess of heavy children among the tall. Based on the Tanner criteria for grading secondary sex characteristics, maturation occurred earlier in the more ponderous girls, although such was not the case for boys. Whereas the Tanner secondary sex characteristics appeared earlier in black girls, white girls reported menarche earlier. The racial and sexual differences known to exist in triceps skinfold were observed for this population. No statistically significant difference was observed overall for height and weight between children within this one community and those of the National Health Examination Survey. However, Bogalusa girls at the 95th percentile were heavier after age 11 than girls of the United States. Also, there was a tendency for white girls in this community to report reaching menarche at an earlier age than black girls, which contrasts slightly with the national sample.

Free and protein-bound serum sugars and serum lipids were analyzed in 65 adult diabetic patients, 10 age-matched controls, and 24 male medical students for correlation of carbohydrate changes with the extent of retinal, renal, and cardiovascular disease. In diabetic sera, both protein-bound sugars and free mannose, fucose, and hexosamine were significantly elevated; free galactose and inositol were elevated in some diabetic patients, and essentially undetectable in sera from controls. Serum triglycerides and pre-beta-lipoproteins were also elevated in diabetics, but alpha-lipoproteins decreased. Although no specific relationships were observed with the extent of retinal and renal disease, bivariate analyses by Pearson coefficients of correlation showed correlations between levels of serum-free mannose and systolic blood pressure, free hexosamine and duration of diabetes, and serum protein-bound fucose and age. Serum triglycerides and pre-beta-lipoprotein levels correlated with insulin therapy. These are preliminary leads of laboratory studies related to carbohydrate macromolecular changes which might aid in a better understanding of the cardiovascular complications associated with diabetes.

Since a positive association between blood pressure and plasma glucose level in child populations has been observed previously, we studied this relationship in a stratified random sample of children ages 7-15 years drawn from a total geographic population. We stratified this population (N = 3524) by diastolic blood pressure and weighted the extreme strata. The sample of children (N = 272) was free of secondary hypertensives and was tested by a restricted glucose tolerance test. As a parameter of cellular glucose kinetics, a "peripheral insulin resistance" was defined as one-hour glucose (mg/dl) X one-hour insulin (microU/ml). For white boys, this product showed an increase from 2745 in the low blood pressure strata to 6615 in the high blood pressure strata. To assess the relationship between blood pressure measured during the reexamination and fasting plasma glucose level, we classified the children according to their peripheral insulin resistance in a low, medium, and high group. After controlling for body weight, only white children in the high blood pressure strata with high insulin resistance had a positive association between fasting plasma glucose and systolic blood pressure. The relationship may be initiated by inappropriate intravascular water retention influencing the blood pressure in children with high peripheral insulin resistance and susceptible to hypertension.

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.

We assessed the relation of risk factors for cardiovascular disease to early atherosclerotic lesions in the aorta and coronary arteries in 35 persons (mean age at death, 18 years). Aortic involvement with fatty streaks was greater in blacks than in whites (37 vs. 17 percent, P less than 0.01). However, aortic fatty streaks were strongly related to antemortem levels of both total and low-density lipoprotein cholesterol (r = 0.67, P less than 0.0001 for each association), independently of race, sex, and age, and were inversely correlated with the ratio of high-density lipoprotein cholesterol to low-density plus very-low-density lipoprotein cholesterol (r = -0.35, P = 0.06). Coronary-artery fatty streaks were correlated with very-low-density lipoprotein cholesterol (r = 0.41, P = 0.04). Mean systolic blood-pressure levels also tended to be higher in the four subjects with coronary-artery fibrous plaques than in those without them: 112 mm Hg as compared with 104 (P = 0.09). These results document the importance of risk-factor levels to early anatomical changes in the aorta and coronary arteries. The progression of fatty streaks to fibrous plaques is uncertain, but these data suggest that a rational approach to the prevention of cardiovascular disease should begin early in life.

• 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 relationships 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. (Am J Dis Child1982;136:855-862)

To investigate whether cuff bladder dimensions relative to the length and circumference of the upper arm affect the outcome of epidemiologic blood pressure surveys, multiple observers took multiple measurements on each of 92 grade school children from Franklinton and 351 children from Bogalusa, Louisiana. For the present study, the broad, hard surrounding cuff of the Physiometrics blood pressure recorder using a transducer embedded in the ample cuff bladder gave "true readings." Baumanometer readings were performed using standard cuff sizes selected according to currently recommended criteria. "Excess pressure reading" equal to mean Baumanometer reading minus mean true reading. "Deficient cuff bladder length" equal to percentage of upperarm circumference not covered by the rubber bladder. Pearson correlation coefficients for the two groups of children supported the hypothesis (at the 5% level of significance) that deficient cuff bladder length is associated with excess pressure reading. The relevant correlation coefficients for the two groups of children were 0.18 and 0.31 (systolic pressure) and 0.24 and 0.19 (diastolic pressure). In addition to sufficient cuff width, the complete surrounding of the entire arm circumference by the rubber bladder is recommended for epidemiologic studies of children.

To examine the effect of smoking on cardiovascular risk factors in youth, we examined 3,145 children ages 8–17 years (88% of the eligible geographic population; 65% white and 35% black) for serum lipids and lipoproteins, anthropometry, and other risk factors, administered a smoking questionnaire (including questions on oral contraceptives for older girls), and validated the smoking history with plasma thiocyanate levels. For the 78% of examined children with complete data, the coefficient of partial correlation between smoking and fasting serum α-lipoprotein (controlling for age) was significantly negative only in white girls ( P P P P P P P

BP was measured in 440 children followed longitudinally from birth to 7 years of age in Bogalusa, LA. Levels, trends, and determinants of BP were evaluated in this newborn cohort. Both systolic and diastolic BP levels remained relatively constant between the ages of 6 months and 7 years. BP levels varied between the different instruments, and differences were also noted between measures obtained using the same instrument before and after venipuncture. White children were noted to have slightly higher levels of systolic and diastolic BP pressure at 6 months and 1 year of age, even after adjustment for body size. Significant prediction of year 7 BP rank occurred as early as 6 months of age for systolic and at 1 year of age for diastolic BP levels. Body size was inconsistently related to BP levels from ages 6 months through 4 years, but the relationship was stronger and more consistent with changes in body size. Of interest is the relatively constant levels of indirect BP during this period of rapid growth, as measured by currently available instruments. These data emphasize the importance of cardiovascular risk factor measurement during early life and of the need to improve methods of indirect BP measurement in infancy.