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BACKGROUND. Recent studies have shown considerable variation in body fatness among children and adolescents defined as obese by a percentile rank for skinfold thickness. METHODS. We examined the relationship between percent body fat and risk for elevated blood pressure, serum total cholesterol, and serum lipoprotein ratios in a biracial sample of 3320 children and adolescents aged 5 to 18 years. Equations developed specifically for children using the sum of subscapular (S) and triceps (T) skinfolds were used to estimate percent fat. The S/T ratio provided an index of trunkal fat patterning. RESULTS. Significant overrepresentation (greater than 20%) of the uppermost quintile (UQ) for cardiovascular disease (CVD) risk factors was evident at or above 25% fat in males (32.2% to 37.3% in UQ) and at or above 30% fat in females (26.6% to 45.4% in UQ), even after adjusting for age, race, fasting status, and trunkal fat patterning. CONCLUSIONS. These data support the concept of body fatness standards in White and Black children and adolescents as significant predictors of CVD risk factors. Potential applications of these obesity standards include epidemiologic surveys, pediatric health screenings, and youth fitness tests.

To alter the adverse natural course of coronary artery disease and its risk factors, primary prevention should begin in childhood.High serum cholesterol, LDL cholesterol (LDL-C) in particular, remains the major determinant of atherosclerotic process beginning in childhood. Selective cholesterol screening of children based on family history is inadequate. Tracking of childhood elevated cholesterol in conjunction with other risk factors into adulthood argues in favor of universal screening in the young. Further, individual adverse levels of LDL-C not only increase the incidence of adulthood dyslipidemia, but also markedly enhances the prevalence of obesity and hypertension seen in the adult population.Screening of all young individuals for serum cholesterol along with a cardiovascular risk factor profile is recommended. Cardiovascular disease remains a public health issue and identifying young individuals at risk is basic to prevention.

The Bogalusa Heart Study, a long-term population study with a continued relationship with a community, addresses the problem of capacity building in minority health research. The study was originally funded as a Specialized Center of Research-Arteriosclerosis (SCOR-A) by the National Heart Lung and Blood Institute (NHLBI). These centers were to conduct research on atherosclerosis, coronary artery disease (CAD), hypertension, diabetes mellitus, and complications of cardiovascular-renal disease as the major causes of deaths in the United States. From earlier research on atherosclerosis, we became interested in the underlying characteristics in early life that would eventually lead to clinical morbidity and mortality from heart disease. An observation at autopsy showed the degree of atherosclerotic involvement in human aortas, from young to older individuals (Figure 1). For example, at age 40 years, marked individual variability occurred in the severity and involvement with atherosclerotic disease. Some individuals showed very little disease, while almost 70% of the surface was diseased in others. Further studies on arterial wall matrix showed aortas from young individuals varied with the extent of disease and its chemical composition. This background stimulated an interest in studying children for early clinical evidence of major adult heart diseases. The Bogalusa Heart Study was begun in 1972 as an epidemiology study of cardiovascular risk factors in children and adolescents; it eventually evolved into observations of young adults. Bogalusa, LA, is a biracial (black/white) rural community 70 miles north of New Orleans, comparable to many other communities in southeastern United States.

Although parent-offspring associations of cardiovascular risk factor variables are known, the age-specific nature of this familial relationship is not clear.This aspect was examined in 727 unrelated children (mean age: 11.2 years) and their parents who participated in the Bogalusa Heart Study during their childhood (mean age: 11.3 years) and adulthood (mean age: 25.5 years).After adjusting for covariates, the mothers' childhood-offspring correlations were consistently higher than mothers' adulthood-offspring correlations for body mass index (BMI) [r = 0.45 vs. 0.32], systolic blood pressure (SBP) [r = 0.30 vs. 0.10], diastolic blood pressure (DPB) [r = 0.22 vs. 0.13] and low-density lipoprotein cholesterol (LDLC) [r = 0.20 vs. 0.11]. In contrast, high-density lipoprotein cholesterol (HDLC) and triglycerides did not show such age-specific trends in mother-offspring correlations. Corresponding father-offspring correlations showed similar patterns, but the differences were of lesser magnitude. Multiple regression analyses using offspring's risk factor variables as dependent variables revealed that parents' childhood obesity, blood pressure and LDLC levels were better predictors of the corresponding variables in the young offspring than parents' adulthood values. Further, sex of either parents or offspring made no difference in the above findings.The magnitude of the familial associations of cardiovascular risk factor variables between parents and offspring are influenced by age. Intrinsic genetic make-up, duration of exposure to environment and gene-environment interactions may play a role in this association.

The US Surgeon General concluded that nicotine in tobacco is addictive. Few studies actually explore the nature of nicotine addiction in youth. In Bogalusa, Louisiana, surveys to assess tobacco usage were administered to 11-18 year olds according to a standardized protocol developed in 1976. In 1991-92, a special substudy explored the nature of nicotine addiction in youth. Overall, 14.7% were current cigarette smokers; however, as many as 44.3% of white females, ages 15-16, indicated they were current smokers. Twelve percent of the surveyed population purchased single cigarettes. Thirty-two percent of current smokers reported they smoke a cigarette within 30 minutes after waking up. Thirty-one percent said they would find it difficult to refrain from smoking in places where it is forbidden. And 23% said they continue to smoke cigarettes when they are ill. From the findings in this study, it is clear there are young people who are addicted to tobacco. It is important to develop prevention of tobacco usage in childhood. Those who are addicted require a carefully developed intervention program to assist them with their cessation efforts.

In adults, cardiovascular risk factors reinforce each other in their effect on cardiovascular events. However, information is scant on the relation of multiple risk factors to the extent of asymptomatic atherosclerosis in young people.We performed autopsies on 204 young persons 2 to 39 years of age, who had died from various causes, principally trauma. Data on antemortem risk factors were available for 93 of these persons, who were the focus of this study. We correlated risk factors with the extent of atherosclerosis in the aorta and coronary arteries.The extent of fatty streaks and fibrous plaques in the aorta and coronary arteries increased with age. The association between fatty streaks and fibrous plaques was much stronger in the coronary arteries (r=0.60, P0.001) than in the aorta (r=0.23, P=0.03). Among the cardiovascular risk factors, body-mass index, systolic and diastolic blood pressure, and serum concentrations of total cholesterol, triglycerides, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol, as a group, were strongly associated with the extent of lesions in the aorta and coronary arteries (canonical correlation [a measure of the association between groups of variables]: r=0.70; P0.001). In addition, cigarette smoking increased the percentage of the intimal surface involved with fibrous plaques in the aorta (1.22 percent in smokers vs. 0.12 percent in nonsmokers, P=0.02) and fatty streaks in the coronary vessels (8.27 percent vs. 2.89 percent, P=0.04). The effect of multiple risk factors on the extent of atherosclerosis was quite evident. Subjects with 0, 1, 2, and 3 or 4 risk factors had, respectively, 19.1 percent, 30.3 percent, 37.9 percent, and 35.0 percent of the intimal surface covered with fatty streaks in the aorta (P for trend=0.01). The comparable figures for the coronary arteries were 1.3 percent, 2.5 percent, 7.9 percent, and 11.0 percent, respectively, for fatty streaks (P for trend=0.01) and 0.6 percent, 0.7 percent, 2.4 percent, and 7.2 percent for collagenous fibrous plaques (P for trend=0.003).These findings indicate that as the number of cardiovascular risk factors increases, so does the severity of asymptomatic coronary and aortic atherosclerosis in young people.

Although the association between parental coronary artery disease (CAD) and its risk factors in the offspring is known, the timing and the course of development of risk factors from childhood to adulthood in the offspring is not known.To examine the association between parental CAD and longitudinal changes in risk factor profile from childhood to young adulthood in offspring.Cohort study.Bogalusa, La, a semirural, biracial community.Individuals with clinically verified parental history of CAD (n=271) vs those without such a history (n = 1253) Mean age at first CAD event was 50 years for fathers and 52 years for mothers.Body mass index, subscapular skinfolds, blood pressure, and triglyceride, cholesterol (total, very low-density lipoprotein [VLDL-C], low-density lipoprotein [LDL-C], and high-density lipoprotein [HDL-C] cholesterols), glucose, and insulin levels.The offspring of parents with CAD were consistently overweight beginning in childhood. Their levels of total serum cholesterol, LDL-C, plasma glucose, and insulin became significantly higher at older ages, because of a higher rate of increase in these risk factors over time. In adulthood, the offspring with a positive parental history had a higher prevalence of obesity (body mass index85th percentile in the National Health and Nutrition Examination Survey I, 35% vs 26%, P=.01), elevated total cholesterol (6.2 mmol/L [240 mg/dL], 8.4% vs 4.8%, P=.05) and LDL-C levels (4.1 mmol/L [160 mg/dL], 12.4% vs 4.7%, P=.05), and hyperglycemia (glucose,6.6 mmol/L, 2.7% vs 0.4%, P.001), as well as a higher coexistence of these conditions (P=.01). Further, the prevalence of dyslipidemia, either involving only LDL-C or LDL-C in combination with HDL-C or triglycerides or both, was significantly higher in the adult offspring with parental CAD.Offspring of parents with early CAD were overweight beginning in childhood and developed an adverse cardiovascular risk factor profile at an increased rate. These observations have important implications for prevention and intervention.

To compare the body mass index (BMI) (weight/height2) and the Ponderal index (PI) (weight/height3) in childhood as predictors of adult overweight in a biracial group of children.Prospective, 15-y follow-up.835 children aged 10-15 y at baseline.Weight in kg and height in m.Overweight, defined as a BMI greater than 27 kg/m2 in young adults.Overall, the BMI and the PI at baseline were identically correlated with the BMI at follow-up (r = 0.64, p0.001). However, the predictions of overweight based on each index were distinctively affected by age, sex and race. The probability of adult overweight among 10-year old children was greater than 0.5 (50% overweight threshold) if their BMI exceeded 17 kg/m2 in black girls, 20 in white girls and 18 in boys of either race. Similarly, the 50% BMI overweight thresholds among 15-year-old children were 23 kg/m2 for black girls, 25 for white girls and 22 for boys of either race. The 50% PI overweight thresholds (in kg/m2) were 12 and 14 for 10-year-old black girls and white girls, respectively; and 14 and 16 for 15-year-old black girls and white girls, respectively. Among boys, the 50% PI threshold was 13 kg/m3 regardless of age or race.The BMI and the PI in childhood were both useful in assessing sex-and race-specific risks of adult overweight. However, assessments based on the Ponderal index were less affected by age and race than those based on the BMI, particularly among boys. Hence, to establish general weight goals for children, aimed at preventing adult obesity, the PI could be a much better choice than the BMI.

To examine the usefulness of childhood low-density lipoprotein cholesterol (LDL-C) measurement for predicting future dyslipidemia and other cardiovascular risk in adulthood.A longitudinal cohort over 15 years was identified from a community study of the natural course of arteriosclerosis: 1169 individuals (34% black), aged 5 to 14 years, were included at initial study.Levels of lipoprotein variables in childhood were associated with levels in adulthood, more strongly for total cholesterol (r = .4-.6) and LDL-C (r = .4-.6) than for high-density lipoprotein cholesterol (r = .2-.4) and triglycerides (r = .1-.4). In a stepwise multiple regression, the childhood level was most predictive of the adulthood level, followed by change in body mass index (weight in kilograms/height in meters squared) from childhood to adulthood, with explained variability (R2) of .29, .30, .27, and .19 for total cholesterol, LDL-C, high-density lipoprotein cholesterol, and triglycerides, respectively. Adulthood dyslipidemia, as defined by the National Cholesterol Education Program criterion, was best predicted by childhood LDL-C level among other lipoprotein variables. Compared with subjects with acceptable childhood risk (LDL-C level,2.84 mmol/L [110 md/dL]), those (6%) with high childhood risk (LDL-C level,or = 3.36 mmol/L [or = 130 mg/dL]) not only had a higher prevalence of dyslipidemic total cholesterol level (24%, 8.3-fold), LDL-C level (28%, 5.4-fold), triglyceride level (7%, sevenfold) and lower HDL-C level (14%, 2.1-fold), but also had a significantly higher (P.05) prevalence of obesity (43%, 1.6-fold) and hypertension (19%, 2.4-fold). In addition, if the childhood LDL-C elevation (90th percentile) was persistent, the prevalence of adult dyslipidemia would be markedly increased (P.001).Adverse levels of LDL-C in childhood persist over time, progress to adult dyslipidemia, and relate to obesity and hypertension as well. National Cholesterol Education Program guidelines to classify cardiovascular risk on the basis of LDL-C level are helpful in targeting individuals at risk early in life.

Earlier we found black-white contrast in insulin levels in adolescents. The purpose of this study is to assess whether this difference is attributable to alterations in insulin secretion and/or clearance.Fasting circulating insulin and C-peptide concentrations were examined in 1157 adolescents aged 11 to 18 years from a biracial community. Fasting plasma C-peptide, C-peptide to insulin ratio, and glucose to insulin ratio were used as indices of insulin secretion, hepatic insulin clearance, and insulin sensitivity, respectively.After adjusting several covariates (age, sexual maturation, and obesity), black adolescents had higher insulin levels (14.99 vs 12.66 microU/mL in girls). However, they had lower C-peptide levels than their white counterparts, indicating lower insulin secretion by pancreatic beta cells in black adolescents. Moreover, black adolescents had lower levels of C-peptide to insulin ratio than white adolescents (0.14 vs 0.17), suggesting reduced hepatic insulin clearance in black adolescents. In addition, significantly lower levels of glucose to insulin ratio in black girls suggest a reduced insulin sensitivity in this group. Further, differences in insulin levels between white and black girls disappeared after adjusting for differences in C-peptide to insulin ratio.These data suggest that elevated insulin levels observed in black adolescents, especially in black girls, may be attributed to their decreased hepatic insulin clearance, not hypersecretion of insulin.

RESEARCHERS RECORDED BLOOD PRESSURE LEVELS of children and adolescents in the Bogalusa Heart Study (black and white populations) and in the Brooks Country Study (Hispanic population). Hispanic children had smaller stature, while whites and Hispanics tended to be fatter than blacks in childhood. In Bogalusa, black boys showed higher blood pressure levels. Hispanic girls showed lower systolic blood pressure than the other ethnic groups. In cultures with a high prevalence of hypertension, such as blacks in the United States, it is important to understand the effect of environmental factors like dietary intake and electrolytes and obesity on the control of hypertension.

The use of fourth phase Korotkoff sound (K4) versus fifth phase Korotkoff sound (K5) for the determination of diastolic blood pressure (DBP) has been a subject of controversy since the indirect method of determining arterial blood pressure was described. Using data from the Bogalusa Heart Study, we evaluated the differences between K4 and K5 (K4-K5) from 4633 subjects 5 to 30 years of age examined between 1987 and 1991. The overall mean difference between K4 and K5 was 9.9 +/- 5.6 mm Hg (mean +/- SD). The average difference was highest in 5 to 8 year olds, where it measured 12.3 +/- 5.5 mm Hg. The average K4-K5 difference fell with increasing age and reached a value of 6.3 +/- 2.6 mm Hg by 25 years of age. For all race/sex groups, the youngest two age groups differed statistically from the oldest age groups in K4-K5 difference (P.006). There were significant differences between blacks and whites (P.015) and between men and women (P.001) for subjects between 13 and 17 years of age. Additional analyses were performed with individuals having K5 = 0 added to yield an expanded population of 5117 persons. Overall, 9.5% had at least one of six measurements of K5 = 0 and most were young subjects: 27% of children 5 to 8 years and 13% of children 9 to 12 years. We conclude that by age 15 there may be no relevant clinical difference in K4-K5. However, in children, K4 and K5 should be recorded and K4 is a more reproducible measure of diastolic blood pressure.

Age and secular trends in dietary fiber intake of children were examined using the 24-hour dietary recall method. Dietary fiber intake of five cohorts of 10-year-olds (n = 1254); two cohorts of 13-year-olds (n = 360); and children ages 10 (n = 767), 13 (n = 249), 15 (n = 108), and 17 (n = 89) years was examined from 1976 to 1988. Total dietary fiber intake remained unchanged from 1976 to 1988, even after adjusting for energy intake; averaging 12 or 5 g/100 calories (kcal). Black children had higher fiber intakes per 1000 kcal than white children from ages 10 to 17 years. Consumption of vegetables and/or soups and breads and/or cereals accounted for 53% (10 years) to 70% (13 years) of the total fiber consumed. When children were stratified into quartiles based on fiber intake per 1000 kcal, the percent of energy from total fat and saturated fat was lower, and the percent of energy from carbohydrates was higher in children with higher fiber intakes per 1000 kcal. Additional studies are needed to document dietary fiber intakes of children and their impact on overall diet composition and cardiovascular risk factors.

To determine dietary fiber intake of children and young adults.Cross-sectional surveys of children and young adults in Bogalusa, La.Twenty-four-hour dietary recalls were collected from 1976 to 1988 on five cohorts of 10-year-olds (n = 1,254), two cohorts of 13-year-olds (n = 360), and young adults (n = 504) 19 to 28 years of age.Dietary fiber intake data were analyzed for age, race, and gender differences and for secular trends. Descriptive and inferential statistics were calculated where appropriate. Dietary composition and food sources were examined for race-specific and gender-specific quartiles for dietary fiber intake adjusted per 1,000 kcal.Even after adjusting for energy intake, total dietary fiber intake remained unchanged from 1976 to 1988, averaging 12 g or 5 g/1,000 kcal. Blacks and males had higher total fiber intakes than whites and females at all ages. Consumption of vegetables and soups and breads and grains accounted for 53% (10-year-olds) to 70% (13-year-olds) of the total fiber consumed. When children were stratified into quartiles on the basis of fiber intake per 1,000 kcal, the percentage of energy from total fat and saturated fat was lower, and the percentage of energy from carbohydrate was higher, in children with higher fiber intakes per 1,000 kcal.Dietary fiber intake of children has remained the same in the past 12 years and is comparable with the intake of young adults, which is well below the recommended level. Children with high fiber intakes (upper quartile) consumed less fat, particularly saturated fat, and more carbohydrate than children with low fiber intakes. Increasing consumption of whole-grain products, fruits, vegetables, and legumes (prepared with minimal added fat) will be necessary to reach the goal of optimal fiber intake and could result in an eating pattern that approaches the current recommendations for dietary fat and saturated fat.

To assess whether circulating insulin is a major contributor to adverse lipid profiles during the transition from adolescence to young adulthood.The association between fasting insulin levels and serum lipid and lipoprotein levels was examined in a cross-sectional survey of 4136 young individuals aged 5 to 30 years from a biracial community.Fasting insulin levels were strongly and positively correlated with serum triglyceride and very-low-density lipoprotein cholesterol levels and negatively correlated with high-density lipoprotein cholesterol levels in all age groups (5 to 11, 12 to 17, 19 to 24, and 25 to 30 years). An increasing impact of insulin level on low-density lipoprotein cholesterol level was observed in young adults aged 25 to 30 years. In multivariate analysis, fasting insulin level was associated with very-low-density lipoprotein cholesterol level for most of the age groups in both races independently of age, sex, glucose levels, obesity, cigarette smoking, and alcohol intake. The independent relationship to low-density lipoprotein cholesterol level persisted in young adults aged 25 to 30 years. The independent and negative association with high-density lipoprotein cholesterol level remained in whites aged 5 to 24 years and blacks aged 19 to 24 years. When individuals were divided into tertiles according to insulin concentration and subscapular skinfold thickness, the independent effect of insulin level and obesity on lipoprotein fractions was also noted. Furthermore, a stronger association of insulin level with lipoprotein fractions was observed in obese than in lean white males.These data indicate that an increasing association of insulin levels with adverse lipoprotein levels in young adults, especially obese individuals, may have adverse consequence for adult cardiovascular diseases.

The functional properties of the apolipoproteins (apoB and apoA-I) governing lipoprotein metabolism make these variables conceptually important as markers for coronary artery disease risk. This aspect was examined in a biracial (black-white) population of children as part of the Bogalusa Heart Study. White children, especially boys, showed lower concentrations of apoA-I and ratios of cholesterol to apoB within low-density lipoprotein (LDL) than did black children. Persistence of apoB concentrations over time, coupled with its strong linkage with apoB gene locus, underscores the value of detecting apoB excess early in life. Further, the impact of apoE genotypes on apoB and apoA-I levels is already evident in childhood. We found that, as a screening test for detecting increased LDL cholesterol, apoB is superior to total cholesterol. Low values for apoA-I concentration, the apoA-I to apoB ratio, and LDL cholesterol to apoB ratio in children are strongly related to parental incidence of myocardial infarction; no such relationship is seen with respect to lipoprotein cholesterols. Thus, expanding screening strategies might be useful for identifying individuals with adverse apolipoprotein profiles early in life.

Cardiovascular risk factors are known to persist over time and to cluster both in childhood and adulthood. Less is known about the persistence of clustering of multiple cardiovascular risk factors comprising adverse levels of systolic blood pressure, the ratio of total cholesterol to high-density lipoprotein cholesterol, and plasma insulin from childhood to young adulthood.In a community study of cardiovascular risk, 1176 individuals (52% female, 44% black) aged 5 through 17 years at baseline were followed up for 8 years.Calculated as sum of the race-, sex-, and age-specific rankings of systolic blood pressure, insulin level, and total to high-density lipoprotein cholesterol ratio, the multiple risk index was shown to track in all four race-sex groups (year 1 vs year 8 correlations, .54 to .67). The magnitude of the overall multiple risk index tracking correlation (r = .64) was significantly stronger than that noted for individual risk factors (r = .34 to .57). Among subjects who were initially in the highest quintile of the multiple risk index, 61% remained there 8 years later. Tracking of the multiple risk index increased progressively with age and ponderal index (weight/[height3]). In a step-wise regression analysis, baseline multiple risk index score, baseline ponderal index, change in ponderal index, and change in height were predictive of the multiple risk index score on follow-up. These predictors explained 45% to 60% of the variability in multiple risk index scores among the race-sex groups.The persistence of multiple cardiovascular risk clustering from childhood to adulthood and the impact of obesity in this regard point to the need for preventive measures aimed at developing healthy lifestyles early in life.

Epidemiological studies of BPs in children and young adults over the past 20 years have contributed considerably to understanding the early onset of primary hypertension. Observations from autopsies and echocardiographic studies, together with long-term BP studies, of children clearly indicate that primary hypertension begins in early childhood. Although abnormal BP levels in children are much lower than the adult criteria used for clinical diagnosis of hypertension, essential hypertension is identifiable in early life. Complex haemodynamic and metabolic mechanisms related to essential hypertension are also being identified in childhood. The development of intervention programs in an attempt to prevent hypertension in its early phases suggests hypertensive cardiovascular disease is preventable. Environmental factors (improved dietary factors, altering electrolyte intake, prevention of obesity and increased activity levels) are critical elements to prevention. Children and young adults identified as high risk for hypertension need to be targeted for prevention of early cardiovascular renal disease. Also, as hypertension is so prevalent, attempts should be made to control environmental factors in the general public. Preventive programmes established by primary healthcare physicians, paediatricians and para-professionals can have a major impact on the reduction of hypertension and its complications of cardiovascular renal disease in the future.

In order to identify potential abnormalities, a cardiovascular risk-factor screening was developed as part of the Fort Polk Heart Smart Program. Serum lipids and lipoproteins, blood pressure, and selected anthropometric indices were measured on 703 individuals. Overweight was more a problem for females, with over 40% having a body mass index greater than 27. The percentage of subjects exceeding National Cholesterol Education Program guidelines increased with age. Some 30% of white men 30-39 years old and 60% of white men above 40 years old had elevated total cholesterol. These observations provide the basis for a health promotion program for young military families.

Lifestyles are major determinants in development of heart disease. Tobacco and alcohol use, physical activity, and hostility, a component of type A, were assessed in a sample of active military men and their wives at Fort Polk, Louisiana. Findings included: (1) a greater frequency of cigarette smoking at Fort Polk compared to national surveys; (2) a higher frequency of alcohol consumption in ages 30-39, and more blacks reported alcohol use than other race groups; (3) a greater frequency of alcohol use at Fort Polk compared to a worldwide military survey; (4) no consistent differences in lipid or blood pressure levels for high and low activity groups of wives; and (5) wives' hostility scores were low, and were not correlated with other cardiovascular risk factors. The implication of lifestyle descriptions is the need for intervention and health promotion, not only for military personnel, but also for their families. The significance of health promotion programs is the eventual reduction of health care costs and the well-being of families and fitness of military personnel.

Serum lipid and lipoprotein distributions and their correlates were examined in white, black, and Hispanic Army personnel and their families (N = 589) as part of the Fort Polk Heart Smart Program. In general, blacks tended to have higher HDL-C and lower triglycerides and VLDL-C than whites and Hispanics, whereas Hispanics tended to manifest higher triglycerides, VLDL-C, and LDL-C than whites. Unlike black and Hispanic men, white men tended to have lower HDL-C than white women. In contrast to white men, both black and Hispanic men displayed elevated LDL-C compared with black and Hispanic women. A considerable proportion of individuals tended to manifest adverse lipoprotein patterns according to National Cholesterol Education Program guidelines for children and adults. Cigarette smoking and alcohol use were the major contributors to the variance of lipoproteins in men, whereas overweight and oral contraceptive use remained the major factors in this regard for women. These results indicate that early targeting of military personnel and their family members for primary prevention is highly desirable.

The relationship between fasting plasma insulin and blood pressure was studied in a cross-sectional survey of children and young adults aged 5 to 26 years.Fasting plasma insulin, glucose, blood pressure, and anthropometric measurements were obtained on 3518 individuals.When divided into four age groups, the analyses showed that fasting insulin was significantly and positively correlated to both systolic and diastolic blood pressure in individuals at all age groups, except at 13 to 17 years. In multivariate regression analyses, fasting insulin remained independently associated with blood pressure levels after controlling for glucose levels, body mass index (weight/height) and skinfold thickness in children (aged 5 to 12 years) and young adults (aged 18 to 26 years), although not in adolescents (aged 13 to 17 years). Moreover, fasting insulin was more strongly related to systolic than to diastolic blood pressure. The fasting blood glucose level did not contribute independently to multivariate prediction of blood pressure in young adults. When the children and young adults were divided into tertiles according to fasting insulin and body mass index, the independent effect of insulin and body mass index on systolic pressure was also seen in children and young adults.The association between plasma insulin and blood pressure noted even in healthy children and young adults help target areas for cardiovascular risk prevention.

To investigate sex differences in the evolution of the QT interval with age.A community-based representative North American population sample of 14,379 children and adults aged from birth to 75 years. The measured QT intervals (QTm) were determined by a computer algorithm and QTm, corrected for heart rate (HR), was expressed as QT index: QTI = (QTm/Tp) x 100, where QTp is the predicted QT from the formula QTp (ms) = 656/(1 + HR/100).The QTI values of females were significantly longer than of males in all age groups from 15 to 50 years tested at yearly intervals. This difference was due to a 20 ms drop in rate-corrected QT values in adolescent males after puberty, whereas QT values of females remained unchanged throughout the growth, maturation and reproductive years. The new QT prediction formula explained 83% of total QT variance in females and 82% in males after adjustment for heart rate and for the observed significant influence of ventricular excitation time (QRS duration) on QT interval in both sexes and a correction for QT age trend in males.The sex difference in the QT interval is due to QT shortening in males after puberty rather than QT prolongation in women during reproductive years. The fact that QRS duration is a significant determinant of the QT interval has important theoretical implications for attempts to model the ventricular repolarization process and it indicates that the traditional concept of reverse sequence of ventricular repolarization is not universally valid in all myocardial regions.

Nutritional adequacy is important when diets and dietary alterations are recommended for children. Concern is expressed that low fat intakes may have deleterious effects on growth and development and may be deficient in total calories and essential nutrients. In a study of the effect of variation in percent fat in the diet, a sample of 871 ten-year-olds was stratified according to four different fat intakes: less than 30% of total kilocalories (kcal), 30% to 35% kcal, 35% to 40% kcal, and greater than 40% kcal. The race/sex distribution was similar within each fat intake group. Fourteen percent of the sample had fat intakes less than 30% of total calories. The amount of calories from breakfast, dinner, and snacks was higher in the children with fat intakes greater than 40% of total calories than those with lower fat intakes. The energy intake of all race/sex groups fell within the recommended range. The low fat intake group was eating 25% less calories than the high fat intake group (1800 kcal vs 2400 kcal). The percentage of calories from carbohydrate, specifically sugar, was greater in the low fat intake group compared with the high fat intake group. Percentage of calories from protein was approximately 13% for all groups. Fiber and starch were the same across all fat intakes.(ABSTRACT TRUNCATED AT 250 WORDS)

Obesity is an important determinant of serum lipids and lipoproteins in adults. Since obesity begins early in life, the impact of obesity of serum lipid and lipoprotein levels was examined in 3311 children and young adults (ages 5 to 26 years) from a totally biracial community. Study subjects were grouped according to race, sex, and age categories (5 to 10 years, 11 to 16 years, 17 to 22 years, and 23 to 26 years), excluding females using oral contraceptives or who were pregnant. Overall, associations increase with age, being most prominently noted in white males. The strong positive relation of ponderosity to low-density lipoprotein cholesterol was indicated in the older age groups with correlation coefficients ranging from r = -.09 in the youngest black males to r = .47 in white males aged 17 to 22 years. A negative association was noted between ponderosity and high-density lipoprotein cholesterol with correlation coefficients ranging from r = .08 in black females aged 17 to 22 years to r = -.39 in the oldest white males. Similar results were seen using subscapular skin-fold thickness as a measure of central obesity. Overweight was defined as exceeding 20% above the National Health Anthropometric and Nutritional Examination Survey II survey 50th percentiles. The prevalence of overweight individuals increased with age, being most prominent in black females. The percent(s) of hypercholesterolemic cases, based on the National Cholesterol Education Program criteria, likewise increased with age. A marked proportion of older white males were classified as borderline high and high for low-density lipoprotein cholesterol. A regression model using subscapular skinfold to predict serum lipids and lipoproteins within each age group indicated a consistent increase in the adverse nature of the lipid profile. Intervention and education programs aimed at reducing obesity at younger ages are recommended to reduce serum lipid and lipoprotein levels developing in young adulthood.

The distribution of serum uric acid and its relationship with cardiovascular risk variables have been studied in 3983 children and young adults, aged 5 to 26 years, drawn from a biracial (black and white) population. For two age groups, 5 to 11 years and 19 to 26 years, white subjects had significantly higher uric acid levels than black subjects, (4.02 mg/dl vs 3.57 mg/dl, p less than 0.0001, and 5.50 mg/dl vs 5.18 mg/dl, p less than 0.0001, respectively). Men in the 19 to 26 years age group had a significantly higher uric acid level than women (6.49 mg/dl vs 4.20 mg/dl, p less than 0.0001). White children and young adults were twice as likely to have levels above clinical limits than blacks, and males more likely to have hyperuricemia than females. Parents with a history of myocardial infarction were more likely to have children with hyperuricemia. Children and young adults with hyperuricemia had significantly higher plasma glucose (p less than 0.01) and insulin (p less than 0.001) levels, total cholesterol level (p less than 0.05), and serum triglyceride (p less than 0.0001), very-low-density lipoprotein cholesterol (p less than 0.01), low-density lipoprotein cholesterol (p less than 0.001), and total protein (p less than 0.0001) levels than subjects without hyperuricemia; high-density lipoprotein cholesterol level was significantly lower (p less than 0.0001) in subjects with hyperuricemia than in those without it.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum lipids (total cholesterol and triglycerides) and lipoprotein cholesterol fractions (low density lipoprotein (LDL) cholesterol, very low density lipoprotein (VLDL) cholesterol, and high density lipoprotein (HDL) cholesterol) have been measured approximately every 3 years on children and young adults since 1973-1974 in Bogalusa, Louisiana, a community of approximately 22,000 individuals, one-third of whom are black and two-thirds of whom are white. A total of 1,586 children were examined both at baseline (1973-1974) and at the most recent survey (1984-1986), providing 12 years of follow-up. The decreases in levels noted during puberty for total cholesterol and LDL cholesterol, primarily for boys, were followed by a rise until age 26 years. HDL cholesterol levels, particularly for white boys, continued to drop after age 14 years, yielding increasingly high LDL cholesterol/HDL cholesterol ratios. Tracking, as measured by both correlation coefficients and persistence at extreme quartiles, was evident for all of the lipids and lipoproteins. The 12-year correlation coefficients were greatest for LDL cholesterol and no trend in the magnitude of the correlation coefficients with age was noted. Tracking for HDL cholesterol was better after age 9 years, particularly for white males. Approximately 50% of those children who had total cholesterol levels or LDL cholesterol levels above the 75th percentile at baseline remained elevated 12 years later. For HDL cholesterol, a trend with age was noted for white boys: 42% of those aged 9-14 years in the lower most quartile persisted in this rank 12 years later. The best predictor of follow-up lipid or lipoprotein level was baseline level. The next best predictor was increase in weight as defined by weight/height, an index of obesity. That serum lipid and lipoprotein levels continue to track from childhood into young adulthood points to the necessity of measurement early in life and, where indicated, the introduction of preventive and interventional programs aimed at developing healthy lifestyles.

Multiple strategies are available to affect children's cardiovascular health. From clinic-based high-risk counseling to broad-based school or community programs, intervention strategies are being developed and tested to find the most effective means of changing the risk factors of youth to assure a healthier future for our children. Since adoption of new behaviors is improved by consistent messages from multiple sources, a concerted effort is needed. The involvement of health professionals, educators, community organizations, industry, and government together will be important to support the adoption of healthy lifestyles for succeeding generations. Intervention through cardiovascular health promotion for school children may well be the future direction for preventive cardiology.

The distributions of serum creatinine levels and their relationship with selected anthropometric and cardiovascular risk variables have been described in 3983 children and young adults, aged 5 to 26 years, obtained from a biracial population, Bogalusa, Louisiana. For both blacks and whites serum creatinine levels increased slowly with age, until 11 years of age when a steeper increase occurred to around 19 years of age. Before this age there was a significant age by sex interaction (p less than 0.0001) in the distributions of serum creatinine. After the age of 19 years mean serum creatinine levels were significantly higher in black men than in white men (1.16 mg/dl vs 1.09 mg/dl, p less than 0.0005) and in black women than in white women (0.87 mg/dl vs 0.84 mg/dl, p less than 0.08). Creatinine levels were also significantly higher in men than in women (1.11 mg/dl vs 0.85 mg/dl, p less than 0.0001). Creatinine clearance, estimated from an equation using serum creatine, age, and weight, showed a steady increase until 13 years of age when a maximum range of 120 to 140 ml/min was reached. By the age of 19 years the clearance had declined to a relatively constant range of 100 to 120 ml/min. Black men had the highest correlation of serum creatinine concentration with height, weight, and lean body mass after adjusting for age. White men had the highest correlation of serum creatinine concentration with uric acid. Diastolic blood pressure becomes an important determinant of creatinine levels by the age of 11 years. The race-sex differences in serum creatinine levels in children and young adults are likely related to body mass.

Many advances have now been made in understanding the early natural history of coronary artery disease and essential hypertension, an understanding that these diseases begin in childhood and that CVD relates to clinical cardiovascular risk factors. Methods have now been established to determine risk factors in the pediatric age and, with a family history, to begin to identify children at potential risk for premature heart disease. Advances have also been made in developing models for intervention and beginning prevention through both high-risk and population strategies directed at schoolchildren. Obviously, both approaches are needed and complement each other. An impressive future is ahead for effective preventive cardiology beginning with children by incorporation of cardiovascular health education and health promotion in elementary schools. Applying behavioral concepts to intervention programs can strengthen their chances of success. The overall good of having children adopt healthy life-styles with an understanding of their necessity is now attainable. It will be the responsibility of physicians to guide the direction of programs being promoted for children.

It is necessary to examine lipid abnormalities at a macromolecular level, with emphasis on the transport lipoproteins rather than on cholesterol and triglyceride values alone. Methods for determining serum lipoproteins, which can be adapted for a small laboratory, are now available and are recommended for general clinical use. It is becoming increasingly apparent that the process of atherosclerosis has a long natural history that begins in childhood, and that it is now possible to study children for potential risk.

Diets of four groups of 10-year-old children (no. = 871) from a biracial community were examined to document eating patterns and to note temporal trends in energy, protein, fat, and carbohydrate intakes. A 24-hour dietary recall method, incorporating numerous quality controls, was adapted for interviewing children. Protein provided 13%, fat 38%, and carbohydrate 49% of calories. Few racial differences in eating patterns were detected. Boys had higher energy intakes than girls, but after diets were adjusted per 1,000 kcal, no other sex differences in intake were found. Snacks yielded roughly one-third of daily energy intake, one-fifth of the day's protein, one-third of the fat, and two-fifths of the total carbohydrate intake. Density of macronutrients within the children's diets was consistent over time. Diets of children in the Bogalusa study typify the American eating pattern and are comparable with those found in major national surveys.

Social and behavioral learning methods, combined with nutrition counseling and innovative education modules, provide a well-rounded approach to eating behavior intervention. Dietitians can apply this multifaceted approach in various settings to maximize eating behavior change.

A large pedigree (N = 356) with a high prevalence of heart disease and associated adverse lipoprotein phenotype was studied. The adverse lipoprotein phenotype is characterized by both low levels of high-density-lipoprotein cholesterol (HDL-C) alone (16.3%) and in combination with other adverse lipoprotein levels (12.8%). In all, 44.2% of all pedigree members had at least one adverse lipoprotein level. Analysis of mating types showed that all lipids and lipoproteins possess familial clustering with 25-36% of offspring above median levels when both parents had levels below the median, while 67-83% had levels above the median when both parents had levels above the median. Using adjusted lipid and lipoprotein levels, a statistically significant linear trend was found between the degree of relationship to pedigree members with heart disease, and both the low-density-lipoprotein cholesterol/high-density-lipoprotein cholesterol (LDL-C/HDL-C) ratio (P less than .05), and the very-low-density-lipoprotein cholesterol (VLDL-C; P less than .01) level. A similar analysis using the prevalence of adverse lipoprotein levels as the dependent variable and degree of relationship to heart diseased pedigree numbers as the independent variable showed significant (P less than .05) relationships with VLDL-C and the LDL-C/HDL-C ratio. Further genetic analyses of this pedigree may reveal genetic mechanisms responsible for the familiality of lipoprotein levels in this pedigree.

To assess relationships between increases in triceps skin-fold thickness (TRSF) and changes in levels of serum lipids and lipoproteins in early life, a biracial sample of 1,598 five to 12 year olds were reexamined five years after an initial examination. Significant positive correlations, controlled for age, were observed between changes in TRSF and changes in levels of serum total cholesterol, serum triglycerides, and low- and very low-density lipoprotein cholesterol. Inverse associations between changes in TRSF and high-density lipoprotein cholesterol were weaker, but also statistically significant. Although females showed the largest increases in TRSF, most associations were stronger in males. Increases in estimated percentage body fat and ponderal index (kilograms per cubic meter) were highly associated with changes in TRSF, but showed slightly different associations with the serum lipids and lipoproteins. Results show that increases in obesity in youth are accompanied by an increasingly atherogenic lipoprotein profile.

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.

The gene frequencies of a polymorphism in the 5'-flanking region of the insulin gene and its relationship to cardiovascular disease risk were studied in a well defined population of children (mean age 5.5 years) from a biracial community. The BglII endonuclease was used for digestion of the DNA around this polymorphic region. The risk factors studied included parental and grandparental self-reported histories of myocardial infarction and diabetes mellitus, fasting glucose and insulin levels, lipoprotein, cholesterol, and triglyceride levels, and skinfold thicknesses and weight. Four alleles were observed at this locus, with the class 2 allele being significantly more common among blacks than whites. Among white children, the class 3 allele was associated with increased risk for grandparental diabetes mellitus. White children with 2 copies of the class 3 allele had significantly higher levels of glucose. Black children with a copy of the class 3 allele had significantly higher levels of insulin. This study indicates that the class 3 allele is potentially associated with risk for diabetes mellitus and coronary heart disease that can be observed in childhood.

The value of BP measurements and family history of cardiovascular disease in predicting future BP status was studied in 1,501 children, initially 2 to 14 years of age, who were examined four times during an 8-year period in the Bogalusa Heart Study. Correlation coefficients between year 1 and year 9 BPs were as follows for systolic and diastolic BPs, respectively: 0.41 and 0.35 (P less than .0001). These correlations were significant in all age groups. For children in the upper quartile of BP at any one prior examination, the percentage remaining in the year 9 upper quartile ranged from 41% to 52% for systolic BP and 35% to 44% for diastolic BP. Three serial BP measurements in the upper quartile increased the percentages remaining in the upper quartile to 68% for systolic BP and 62% for diastolic BP. Conversely, of those children not in the upper quartile of systolic BP at year 9, 96.8% did not have all three prior measurements in the upper quartile. Family history of hypertension was shown to independently predict year 9 systolic BP status. These results confirm the importance of serial BP measurements and family history of hypertension for the practicing physician.

The Heart Smart Family Health Promotion identified elementary-school-age children with elevated blood pressure (BP), based on sex-, race-, height-specific 90th percentiles, and ponderal index (wt/ht3), based on sex-, race-, and age-specific 90th percentiles (norms developed in the Bogalusa Heart Study). These children and their parents were recruited into a behavioral program aimed at reducing cardiovascular (CV) risk factors for both children and parents and preventing "tracking" of children's elevated risk factors into adulthood. Cardiovascular screening consisted of BP, anthropometric evaluation, serum lipids, and 24-hour urinalysis. Self-reported assessments were personal and family medical history, eating, exercise, smoking, and alcohol behaviors. Both child and parent subjects were predominantly black and female. Data were stable over two baseline measurements and indicated CV risk factor abnormalities in one or both of the parents selected: 67% of the black parents and 25% of the white parents were hypertensive; 91% had positive familial CV history; 41% had total cholesterol greater than or equal to 220 mg/dl; 50% had LDL-C levels greater than or equal to 140 mg/dl; 74% were overweight; 44% were smokers; and 91% were completely sedentary. Using percentile grids to identify children with elevated BP also identifies families with hypertension and associated risk factors.

Despite encouraging reductions in mortality rates from coronary heart disease (CHD), it remains a major public health problem and the leading cause of death in the United States. Although various explanations have been proposed for declining death rates, a consensus exists regarding the importance of lifestyle alterations for risk factor reduction. Because cardiovascular (CV) risk-related behavioral patterns are acquired during childhood, numerous school-based CV health promotion programs have been implemented. The effectiveness of CV research studies for children during the last decade are reviewed. Intervention strategies to prevent heart disease include (1) the population or public health approach and (2) the high-risk approach. The "Heart Smart" model intervention project is utilized to describe these two main strategies. Policy, position statements, and initiatives on CV risk factors from major professional societies and associations, in addition to governmental organizations and offices, are also provided. Primary care physicians, particularly pediatricians and family practitioners, as well as cardiologists can play a crucial role in the prevention of CHD and essential hypertension through efforts and practices in their offices, the schools, and the community at large. The changing and expanding role of physicians interested in preventive child health care is emphasized, including involvement in school- and community-based CV health promotion programs. More comprehensive CV model projects such as "Heart Smart," which intervene on the total school environment, are critical to the reduction of CV disease in the United States and abroad.