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Resting heart rates were ascertained during the 1978-1979 school year in 3590 children aged 5-17 years in the biracial geographic population of Bogalusa, Louisiana. These rates were found to be relatively independent of the method of measurement, whether supine by physician's stethoscope or dressed sitting radial pulse taken by a nurse, and in either case adhering to a strict measurement protocol. Apart from the known influences of age and sex, the authors found a small but consistent racial influence, with whites having 3-4 beats/min higher rates than blacks. Controlling for age, the authors found heart rate to be positively correlated with blood pressure in whites and with subcapsular skinfold thickness in boys. No consistent relation between heart rate and amount of cigarettes smoked was observed. Boys in the upper five percentiles of blood pressure-heart rate ("double") product values were found to have about twice the subscapular skinfold thickness compared to the lower five percentiles. Likewise, boys in the upper five percentiles of subscapular skinfold thickness had significantly increased double products. Since the double product is an index of cardiac oxygen consumption, this finding could point to a possible etiologic link between obesity and chronic cardiac stress in males beyond the mediation of lipoproteins, cholesterol, and diabetes mellitus in contributing to atherosclerotic heart disease, but this issue needs further study. Ascertainment of resting heart rate provides an additional parameter in the study of cardiovascular risk factor variables, in youth as in adulthood, to supplement the natural history of the atherosclerosis-hypertension syndrome with its sequelae.

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.

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.

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.

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.

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.