Effects of race, cigarette smoking, and use of contraceptive medications on resting energy expenditure in young women.

The prevalence of obesity is higher in Black women than in White women (JAMA 1994;272:205-11; Arch Pediatr Adolesc Med 1995;149:1085-91). Although it has been shown that Black women have a lower resting energy expenditure (REE), factors affecting REE remain unclear. This 1996-1997 study in Cincinnati, Ohio, assessed racial differences in REE and their determinants in a biracial cohort of 152 healthy young women aged 18-21 years. Two indirect calorimetric measurements were obtained during two overnight hospital admissions 10-14 days apart. Body composition was measured by using dual-energy x-ray absorptiometry. Mean REE (adjusted for body composition, smoking, and contraceptive medication use) was significantly (p = 0.04) lower by 71 kcal/day in Black women (1,453 (standard error, 21) kcal/day) than in White women (1,524 (standard error, 19) kcal/day). Smoking was associated with a REE that was 68 kcal/day higher for both groups (p = 0.03). A trend (p = 0.07) toward increased REE (by 46 kcal/day) was found with contraceptive medication use. In conclusion, young Black women had a significantly lower REE than did White women. Cigarette smoking significantly increased REE. The apparent presence of a more parsimonious energy metabolism in Black women suggests that maintenance of energy homeostasis requires particular vigilance in this high-risk population.

Racial divergence in adiposity during adolescence: The NHLBI Growth and Health Study.

BACKGROUND: Black women are particularly vulnerable to obesity, with a prevalence rate of >50%. The higher mortality and morbidity from cardiovascular disease, stroke, and diabetes have been attributed, in part, to their obesity. In recent years, a particular public health concern is the increasing secular trend in obesity with an even greater racial disparity, especially in girls and women. Between the early 1960s and late 1980s, the prevalence of obesity tripled in young black girls 6 to 11 years of age, while it doubled in white girls. Similarly, both overweight and obesity in adolescent girls 12 to 17 years of age also increased, with a greater increase again seen in adolescent black girls. This secular trend in obesity with a greater increase in black girls signals a potentially grave future chronic disease burden on black women, which is already higher than in white women. The increasing occurrence in children and adolescents of noninsulin-dependent diabetes, traditionally viewed as an adult-onset condition, may be a consequence of the currently high prevalence of obesity in American youth. Not surprisingly, this condition is seen more frequently among black youths. Prepubescent black girls are generally leaner than age-comparable white girls, but by 20 years of age, black women are considerably heavier than are white women. Thus, it is assumed that the racial disparity in adiposity evolves during adolescence. However, the specific age at which this occurs and underlying factors are yet to be identified because of the current paucity of longitudinal cohort data. OBJECTIVES: In 1985, the National Heart, Lung, and Blood Institute (NHLBI) initiated a 10-year longitudinal multicenter study (the NHLBI Growth and Health Study [NGHS]) to investigate the development of obesity in black and white girls during adolescence and its environmental, psychosocial, and cardiovascular disease risk factor correlates. The purpose of this report is to examine the natural history of adiposity and weight accretion during adolescence in a biracial cohort of girls to investigate the evolution of the racial divergence in adiposity and to examine the relationships between increases in adiposity and pubertal maturation, energy intake, and physical activity. PARTICIPANTS AND SETTING: A total of 2379 black (51%) and white (49%) girls, 9 to 10 years of age, were recruited from public and parochial schools in Richmond, California, and Cincinnati, Ohio, and from families enrolled in a large health maintenance organization in the Washington, DC area. Participant eligibility was limited to girls and their parents who declared themselves as being either black or white and who lived in racially concordant households. DESIGN AND STATISTICAL ANALYSIS: The NGHS is a multicenter prospective study of black and white girls with annual visits from 9 to 10 years of age through 18 to 19 years of age. The follow-up rate was 89% at the 10th annual visit. Skinfold measurements were obtained at the triceps, suprailiac, and subscapular sites with Holtain calipers. Sexual maturation was assessed by trained registered nurses. The onset of menarche was ascertained annually by questionnaire. All clinical assessments were conducted using a common protocol by centrally trained staff. Longitudinal regression (generalized estimating equations) models were used to examine the relationship between adiposity and race, age, pubertal maturation, daily energy intake, and physical activity. MAIN OUTCOME MEASURES: The main outcome measure was the sum of skinfolds (SSF) at the triceps, subscapular, and suprailiac sites as an index of adiposity for comparison between the 2 racial groups. Body mass index (BMI; weight in kilograms divided by height in meters, squared) distributions were examined by age and race. RESULTS: Racial differences in SSF, unadjusted for maturation, were evident at 10 years of age. For each chronological age, there was a higher proportion of black girls with more advanced pubertal maturation than white girls. The 15th percentiles for SSF were similar and remained thus throughout the study. The median for SSF for black girls, although similar to the median SSF of white girls at 9 years of age, became greater for black girls at 12 years of age (36 mm vs 32.5 mm) and at age 19 years the difference was 6 mm (49.5 mm vs 43.5 mm). In contrast, the difference in the 85th as well as the 95th percentile values for SSF were substantially higher in black girls at all ages (9 mm and 10 mm, or 18% and 15%, respectively, at age 9 years) and these racial differences widened with age (20 mm and 26 mm, or 25% and 24%, respectively, by age 19 years). The racial difference in the median BMI increased from 0.4 to 2.3 kg/m(2) between ages 9 and 19 years. Unlike SSF at the 15th percentile, the BMI for lean 9-year-old black girls was ~3% higher than whites. (ABSTRACT TRUNCATED)

Long-term safety and efficacy of a cholesterol-lowering diet in children with elevated low-density lipoprotein cholesterol: seven-year results of the Dietary Intervention Study in Children (DISC).

OBJECTIVE: Diets reduced in fat and cholesterol are recommended for children over 2 years of age, yet long-term safety and efficacy are unknown. This study tests the long-term efficacy and safety of a cholesterol-lowering dietary intervention in children. METHODS: Six hundred sixty-three children 8 to 10 years of age with elevated low-density lipoprotein cholesterol (LDL-C) were randomized to a dietary intervention or usual care group, with a mean of 7.4 years' follow-up. The dietary behavioral intervention promoted adherence to a diet with 28% of energy from total fat, <8% from saturated fat, up to 9% from polyunsaturated fat, and <75 mg/1000 kcal cholesterol per day. Serum LDL-C, height, and serum ferritin were primary efficacy and safety outcomes. RESULTS: Reductions in dietary total fat, saturated fat, and cholesterol were greater in the intervention than in the usual care group throughout the intervention period. At 1 year, 3 years, and at the last visit, the intervention compared with the usual care group had 4.8 mg/dL (.13 mmol/L), 3.3 mg/dL (.09 mmol/L), and 2.0 mg/dL (.05 mmol/L) lower LDL-C, respectively. There were no differences at any data collection point in height or serum ferritin or any differences in an adverse direction in red blood cell folate, serum retinol and zinc, sexual maturation, or body mass index. CONCLUSION: Dietary fat modification can be achieved and safely sustained in actively growing children with elevated LDL-C, and elevated LDL-C levels can be improved significantly up to 3 years. Changes in the usual care group's diet suggest that pediatric practices and societal and environmental forces are having positive public health effects on dietary behavior during adolescence.

Efficacy and safety of lowering dietary intake of total fat, saturated fat, and cholesterol in children with elevated LDL cholesterol: the Dietary Intervention Study in Children.

BACKGROUND: Few studies have shown the efficacy and safety of lower-fat diets in children. OBJECTIVE: Our objective was to assess the efficacy and safety of lowering dietary intake of total fat, saturated fat, and cholesterol to decrease LDL-cholesterol concentrations in children. DESIGN: A 6-center, randomized controlled clinical trial was carried out in 663 children aged 8-10 y with LDL-cholesterol concentrations greater than the 80th and less than the 98th percentiles for age and sex. The children were randomly assigned to either an intervention group or a usual care group. Behavioral intervention promoted adherence to a diet providing 28% of energy from total fat, <8% from saturated fat,

Longitudinal changes in physical activity in a biracial cohort during adolescence.

PURPOSE: This report describes the development and use of two self-report methods and an objective measure to assess longitudinal changes in physical activity in a large biethnic cohort of young girls from childhood through adolescence. METHODS: The NHLBI Growth and Health Study (NGHS) is a multicenter study of obesity development in 2379 black and white girls followed from ages 9-10 yr to 18-19 yr (NGHS years 1-10). A Caltrac activity monitor was used to objectively quantify activity levels in years 3-5. A 3-d diary (AD) and a habitual patterns questionnaire (HAQ) were administered annually and biannually, respectively, to subjectively quantify physical activity levels. The changing pattern of activities as the girls matured during the 10-yr study period necessitated periodic form changes. Empirical analytic approaches were developed to help distinguish between true longitudinal changes in activity levels from potential numerical artifacts resulting from modifications in forms. RESULTS: The longitudinal activity data indicate a steep decline in the level of reported activity from baseline to year 10 as indicated by AD scores (446.8 to 292.1 MET-min x d(-1), 35%) as well as by HAQ scores (29.3 to 4.9 MET-times x wk(-1), 83%). This parallel trend in the pattern of the decline in activity among the two self-report methods was mirrored by a similar decline using the Caltrac method of physical activity assessment. From years 3 to 5, the AD decreased by 22%, whereas both the HAQ and Caltrac declined by 21%. CONCLUSION: The longitudinal data on physical activity collected in the NGHS cohort further confirm a dramatic decrease in the overall level of physical activity during the transition from childhood to adolescence. The consistency among the three methods indicate that both the AD and HAQ are useful tools for the assessment of activity levels in adolescent girls.

Correlates of lipoprotein(a) levels in a biracial cohort of young girls: the NHLBI Growth and Health Study.

Elevated levels of lipoprotein(a) [Lp(a)] are associated with increased risk for coronary heart disease (CHD). However, racial differences in both Lp(a) levels and their associated CHD risk are observed, with African Americans having, on average, higher Lp(a) levels than US whites but not the expected increase in CHD risk. We determined Lp(a) levels and their correlates in a large cohort (n = 2379) of black and white girls, ages 9 to 10 years, at the baseline visit of a longitudinal study of obesity development, the National Heart, Lung, and Blood Institute Growth and Health Study. Lp(a) levels were available for 1269 girls. The median Lp(a) level in black girls was over 3-fold higher than that in white girls. Associations were examined between Lp(a) levels and low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol, apolipoprotein B, triglycerides, adiposity, pubertal maturation stage, body fat patterning (triceps/truncal skinfold ratio), and dietary fat (Keys' score). In black girls multiple regression analysis identified LDL-C (P <.001) and adiposity (P =. 08) as predictors of Lp(a) levels. In white girls only LDL-C (P =. 02) was associated with Lp(a). In conclusion, the level of Lp(a) was significantly higher in black girls. Our study also revealed a racial difference in correlates of Lp(a), such as LDL-C and adiposity. Whether this racial difference is due to an underlying biologic difference or is merely a reflection of a greater statistical power to detect a relationship with the level, which was 2.5-fold higher in black girls than in white girls, needs further investigation.

National trends in the management of cardiovascular disease risk factors in children: second NHLBI survey of primary care physicians.

BACKGROUND: The evidence that atherosclerosis begins during adolescence has led to the belief that primary prevention of cardiovascular disease (CHD) should commence in childhood. Although several national guidelines have been issued for the detection and treatment of CHD risk factors in children, concerns continue to be expressed regarding what constitutes appropriate measures and when to institute such measures in children. A 1988 national survey of primary care physicians revealed variation in the management of CHD risk factors in children by physician categories, which suggested the underlying quandary among physicians regarding CHD risk factors in children. OBJECTIVE: To assess current clinical management of pediatric CHD risk factors in the primary care setting and also to evaluate time trends between the current and 1988 surveys. METHODS: A 25-minute telephone survey was conducted with 1036 of eligible physicians (ie, >20 hours per week direct patient care including at least five pediatric patient contacts) selected from a national probability sample in three practice categories (family practitioners, pediatricians, and general practitioners). The questionnaire assessed the current practice of these physicians in the primary care setting regarding cholesterol and blood pressure (BP) screening and treatment, both nonpharmacologic and pharmacologic, and physician attitude and knowledge. RESULTS: Cholesterol screening in children was performed by 75.7% of all physicians. Nonscreening was highest among general practitioners (38%) and lowest among pediatricians (12%). BP was measured by almost all physicians. The majority of physicians (71%) prescribed diet as the first cholesterol-lowering step, but approximately 16% also used pharmacologic therapy. Cholesterol synthesis inhibitors and bile acid sequestrants were the drugs used most commonly. Approximately 25% of physicians have used drugs in children to treat high BP. Diuretics and beta-blockers were used most frequently. More than one fourth of the physicians had some concern about identifying and treating children for CHD risk factors. There was slightly less cholesterol measurement in 1995 compared with 1988, and no notable increase in the knowledge regarding major CHD risk factors. CONCLUSION: The results of the second National Heart, Lung, and Blood Institute survey of primary care physicians suggest that additional inroads need to be made in the dissemination of the national guidelines for the management of CHD risk factors in children, including appropriate use of pharmacologic agents.

Longitudinal correlates of change in blood pressure in adolescent girls.

The objective of this study was to assess the longitudinal changes in blood pressure in black and white adolescent girls and evaluate potential determinants of changes in blood pressure, including sexual maturation and body size. A total of 1213 black and 1166 white girls, ages 9 or 10 years at study entry, were followed up through age 14 with annual measurements of height, weight, skinfold thickness, stage of sexual maturation, systolic and diastolic blood pressures, and other cardiovascular risk factors. Average blood pressures in black girls were generally 1 to 2 mm Hg higher than in white girls of similar age over the course of the study. Age, race, stage of sexual maturation, height, and body mass index (kg/m2) were all significant univariate predictors of systolic and diastolic blood pressures in longitudinal regression analyses. Black girls had a significantly smaller increase in blood pressure for a given increase in body mass index compared with white girls. The predicted increases in blood pressure per unit increase in body mass index (mm Hg per kg/m2) were as follows: systolic, 0.65+/-0.04 in whites and 0.52+/-0.04 in blacks (P<.001); diastolic fourth Korotkoff phase, 0.31+/-0.04 in whites and 0.15+/-0.03 in blacks (P<.001); and diastolic fifth Korotkoff phase, 0.31+/-0.05 in whites and 0.16+/-0.04 in blacks (P<.001). Understanding of the determinants of the racial differences in blood pressure could provide the rationale for future interventions to reduce the excess cardiovascular mortality in black compared with white women.

Self-esteem and adiposity in black and white girls: the NHLBI Growth and Health Study.

PURPOSE: Obesity is assumed to have a negative impact on self-esteem because of the associated social stigmatization in Western society. Studies of the psychological effect of obesity in children are inconclusive and limited, particularly pertaining to minority populations. Most studies have assessed global rather than domain-specific measures of self-esteem and hence, may have lacked specificity to detect impairment of certain aspects of self-esteem most closely associated with obesity. The purpose of this study is to examine the effect of adiposity and other environmental factors on measures of perceived competence and self-adequacy in 2205 black and white girls aged 9-10 years. METHODS: Domain-specific measures of self-esteem were studied by race and degree of adiposity, using Harter's "Self-Perception Profile for Children". Three Harter scales deemed more relevant to obesity (social acceptance (SA), physical appearance (PA), and global self-worth (GSW)) were selected for univariate and multivariate linear regression models to examine relationships between self-esteem level and adiposity (measured by the sum of triceps, subscapular, and suprailiac skinfolds (SSF)), race, pubertal maturation, and parental education. The relationship between adiposity and Harter scores was further examined with LOESS curves and also by comparing the mean scores of each quintile of SSF by race, as well as inter-quintile differences within race. RESULTS: Adiposity in general impacted negatively on the scores of all three selected Harter scales. There was also racial variation in the relationship between the scores and adiposity, with the magnitude of the effect somewhat less in black girls. White girls exhibited a significant inverse relationship between SSF and SA scores while, in striking contrast, there was no variation in scores in black girls across all ranges of adiposity. Although there was a significant inverse relationship between adiposity and PA and GSW in both groups, the slope was steeper in white girls, particularly at higher ranges of SSF. Non-linearity in the relationship between SSF and the scores was seen in SA and PA scales. CONCLUSIONS: The present study demonstrated a significant negative association between adiposity and the level of self-esteem in girls as young as 9 to 10 years. There were also intriguing racial differences in the selected domains of esteem. These results may help better understand cultural differences regarding the psychological impact of obesity and could be used to formulate appropriate strategies for public health policy.

Effects of diet and sexual maturation on low-density lipoprotein cholesterol during puberty: the Dietary Intervention Study in Children (DISC).

BACKGROUND: The Dietary Intervention Study in Children (DISC) is a multicenter, randomized, controlled clinical trial designed to examine the efficacy and safety of a dietary intervention to reduce serum LDL cholesterol (LDL-C) in children with elevated LDL-C. METHODS AND RESULTS: The effects of dietary intake of fat and cholesterol and of sexual maturation and body mass index (BMI) on LDL-C were examined in a 3-year longitudinal study of 663 boys and girls (age 8 to 10 years at baseline) with elevated LDL-C levels. Multiple linear regression was used to predict LDL-C at 3 years. For boys, LDL-C decreased by 0.018 mmol/L for each 10 mg/4.2 MJ decrease in dietary cholesterol (P<.05). For girls, no single nutrient was significant in the model, but a treatment group effect was evident (P<.05). In both sexes, BMI at 3 years and LDL-C at baseline were significant and positive predictors of LDL-C levels. In boys, the average LDL-C level was 0.603 mmol/L lower at Tanner stage 4+ than at Tanner stage 1 (P<.01). In girls, the average LDL-C level was 0.274 mmol/L lower at Tanner stage 4+ than at Tanner stage 1 (P<.05). CONCLUSIONS: In pubertal children, sexual maturation, BMI, dietary intervention (in girls), and dietary cholesterol (in boys) were significant in determining LDL-C. Sexual maturation was the factor associated with the greatest difference in LDL-C. Clinicians screening for dyslipidemia or following dyslipidemic children should be aware of the powerful effects of pubertal change on measurements of lipoproteins.

Safety of a fat-reduced diet: the Dietary Intervention Study in Children (DISC).

OBJECTIVE: To assess the relationship between energy intake from fat and anthropometric, biochemical, and dietary measures of nutritional adequacy and safety. DESIGN: Three-year longitudinal study of children participating in a randomized controlled trial; intervention and usual care group data pooled to assess effects of self-reported fat intake; longitudinal regression analyses of measurements at baseline, year 1, and year 3. PARTICIPANTS: Six hundred sixty-three children (362 boys and 301 girls), 8 to 10 years of age at baseline, with elevated low-density lipoprotein cholesterol, who are participants of the Dietary Intervention Study in Children. MEASURES: Energy intake from fat assessed from three 24-hour recalls at each time point was the independent variable. Outcomes were anthropometric measures (height, weight, body mass index, and sum of skinfolds), nutritional biochemical determinations (serum ferritin, zinc, retinol, albumin, beta-carotene, and vitamin E, red blood cell folate, and hemoglobin), and dietary micronutrients (vitamins A, C, E, thiamin, riboflavin, niacin, vitamins B-6, B-12, folate, calcium, iron, zinc, magnesium, and phosphorus). RESULTS: Lower fat intake was not related to anthropometric measures or serum zinc, retinol, albumin, beta-carotene, or vitamin E. Lower fat intake was related to: 1) higher levels of red blood cell folate and hemoglobin, with a trend toward higher serum ferritin; 2) higher intakes of folate, vitamin C, and vitamin A, with a trend toward higher iron intake; 3) lower intakes of calcium, zinc, magnesium, phosphorus, vitamin B-12, thiamin, niacin, and riboflavin; 4) increased risk of consuming less than two-thirds of the Recommended Dietary Allowances for calcium in girls at baseline, and zinc and vitamin E in boys and girls at all visits. CONCLUSIONS: Lower fat intakes during puberty are nutritionally adequate for growth and for maintenance of normal levels of nutritional biochemical measures, and are associated with beneficial effects on blood folate and hemoglobin. Although lower fat diets were related to lower self-reported intakes of several nutrients, no adverse effects were observed on blood biochemical measures of nutritional status. Current public health recommendations for moderately lower fat intakes in children during puberty may be followed safely.

Nutrient intake and blood pressure in the Dietary Intervention Study in Children.

Delineating the role that diet plays in blood pressure levels in children is important for guiding dietary recommendations for the prevention of hypertension. The purpose of this study was to investigate relationships between dietary nutrients and blood pressure in children. Data were analyzed from 662 participants in the Dietary Intervention Study in Children who had elevated low-density lipoprotein cholesterol and were aged 8 to 11 years at baseline. Three 24-hour dietary recalls, systolic pressure, diastolic pressure, height, and weight were obtained at baseline, 1 year, and 3 years. Nutrients analyzed were the micronutrients calcium, magnesium, and potassium; the macronutrients protein, carbohydrates, total fat, saturated fat, polyunsaturated fat, and monounsaturated fat; dietary cholesterol; and total dietary fiber. Baseline and 3-year longitudinal relationships were examined through multivariate models on diastolic and systolic pressures separately, controlling for height, weight, sex, and total caloric intake. The following associations were found in longitudinal analyses: analyzing each nutrient separately, for systolic pressure, inverse associations with calcium (P < .05); magnesium, potassium, and protein (all P < .01); and fiber (P < .05), and direct associations with total fat and monounsaturated fat (both P < .05); for diastolic pressure, inverse associations with calcium (P < .01); magnesium and potassium (both P < .05), protein (P < .01); and carbohydrates and fiber (both P < .05), and direct associations with polyunsaturated fat (P < .01) and monounsaturated fat (P < .05). Analyzing all nutrients simultaneously, for systolic pressure, direct association with total fat (P < .01); for diastolic pressure, inverse associations with calcium (P < .01) and fiber (P < .05), and direct association with total and monounsaturated fats (both P < .05). Results from this sample of children with elevated low-density lipoprotein cholesterol indicate that dietary calcium, fiber, and fat may be important determinants of blood pressure level in children.

Quantitative effects of the apolipoprotein E polymorphism in a biracial sample of 9-10-year-old girls.

Genetic polymorphism at the apolipoprotein E locus (APOE) has been shown to have a significant impact on quantitative risk factors for coronary artery disease (CAD) in diverse populations. However, despite the recognition that atherosclerosis begins in childhood and that genetic factors are related to the initial stages of atherosclerosis, prior studies were carried out mostly on adults and little attention has been paid to genetic risk factors for CAD in children. We have examined the impact of APOE polymorphism on quantitative risk factors for CAD (apoAI, apoB, TC, LDL-C, HDL-C and TG) in a sample of 647 African American and 573 White 9-10-year-old girls who were enrolled in the National Heart, Lung and Blood Institute Growth and Healthy Study. The frequencies of the APOE*2, APOE*3 and APOE*4 alleles were 0.09, 0.76 and 0.15 in Whites and 0.11, 0.70 and 0.19 in African Americans, respectively. The APOE*2 allele was significantly associated with lower mean levels of LDL-C and apoB and the APOE*4 allele with higher levels of LDL-C and apoB in both racial groups. Variation in maturation stage, body fat and fat patterning, as assessed by skin fold measures and waist/hip ratio, accounted for a significant proportion of the variation in quantitative CAD risk factors.

Sexual maturation and racial differences in blood pressure in girls: the National Heart, Lung, and Blood Institute Growth and Health Study.

OBJECTIVE: To evaluate racial differences in blood pressure in girls aged 9 to 10 years in the National Heart, Lung, and Blood Institute Growth and Health Study (NGHS) and to evaluate the extent to which racial differences in blood pressure are explained by other factors, including sexual maturation and body size. METHODS: The NGHS enrolled 539 black and 616 white girls aged 9 years, and 674 black and 550 white girls aged 10 years. Racial differences in blood pressure were examined. Relationships of stage of sexual maturation, height, and skinfold thickness with systolic and diastolic blood pressure were evaluated by multiple regression analysis. RESULTS: The black girls had significantly higher systolic (102.0 +/- 8.90 vs 100.5 +/- 9.42 mm Hg, p <0.001) and diastolic (58.0 +/- 12.0 vs 56.5 +/- 12.51 mm Hg, p <0.01) blood pressures than the white girls. The black girls were also more advanced in sexual maturation and were taller (142.9 +/- 7.94 vs 139.6 +/- 7.05, p <0.001) and heavier (39.6 +/- 11.24 vs 35.3 +/- 8.73 kg, p <0.001) than the white girls. Both systolic and diastolic blood pressure were significantly correlated with level of maturation, height, weight, and sum of skinfolds. Stage of maturation was found to account for the difference in blood pressure between black girls and white girls. In a multiple regression analysis, controlling for height (for diastolic blood pressure) and for both height and sum of skinfolds (for systolic blood pressure) eliminated the effects of race and stage of maturation on blood pressure. CONCLUSION: Racial differences in blood pressure were observed for 9- and 10-year-old girls and are explained by the fact that black girls were more mature than white girls. The effect of sexual maturation on blood pressure appears to operate through height and body fat. The effect of obesity may be more important for systolic than for diastolic blood pressure. Continuation of racial differences in blood pressure may result in a higher prevalence of hypertension for black women.

Race, socioeconomic status, and obesity in 9- to 10-year-old girls: the NHLBI Growth and Health Study.

The purpose of this investigation was to determine whether measures of socioeconomic status (SES) are inversely associated with obesity in 9- to 10-year-old black and white girls and their parents. Subjects were participants in the Growth and Health Study (NGHS) of the National Heart, Lung, and Blood Institute. Extensive SES, anthropometric, and dietary data were collected at baseline on 2379 NGHS participants. The prevalence of obesity was examined in the NGHS girls and parents in relation to SES and selected environmental factors. Less obesity was observed at higher levels of household income and parental education in white girls but not in black girls. Among the mothers of the NGHS participants who were seen, lower prevalence of obesity was observed with higher levels of income and education for white mothers, but no consistent patterns were seen in black mothers. Univariate logistic models indicated that the prevalence of obesity was significantly and inversely associated with parental income and education and number of parents in the household in white girls whereas caloric intake and TV viewing were significantly and positively associated with obesity. Among black girls, only TV viewing was significantly and positively associated with the prevalence of obesity. Multivariate logistic regression models revealed that lower parental educational attainment, one-parent household, and increased caloric intake were significantly associated with the prevalence of obesity in white girls; for black girls, only increased hours of TV viewing were significant in these models. It is concluded that socioeconomic status, as measured by education and income, was related to the prevalence of obesity in girls, with racial variation in these associations. A lower prevalence of obesity was seen at higher levels of socioeconomic status in white girls, whereas no clear relationship was detected in black girls. These findings raise new questions regarding the correlates of obesity in black girls.

The role of dietary fiber in the development and treatment of childhood obesity.

Childhood obesity is viewed as a public health problem in the United States because of its assumed high prevalence and increasing secular trend. The best estimate of the genetic contribution to obesity ranges from 5% to 25%. Environmental factors play a major role in obesity development. Low income and a low level of education have been associated with obesity, particularly among white women. Caloric intake as a risk factor for obesity has not been clearly established. This lack of a clear-cut association may be attributable to the problem of accurately measuring caloric intake. Several studies have linked increased total fat intake, rather than caloric intake, with obesity. Some studies have linked television viewing to obesity in children. Obesity is rare among the populations of developing countries, where dietary fiber intake is high. Explanations for the role of dietary fiber in obesity include a reduced caloric density of the foods, a slower rate of food ingestion, and possible effects on satiety. Most studies on the role of fiber in the treatment of obesity have been somewhat limited by lack of comparison groups, inadequate sample sizes, and short durations of the observations. However, although limited, the available evidence suggests that fiber potentially could play a useful role in weight reduction. For children, fiber administration should be considered as an adjuvant therapy rather than a primary modality, because fiber might aid in promoting satiety during meals and curbing hunger between meals.(ABSTRACT TRUNCATED AT 250 WORDS)

The Dietary Intervention Study in Children (DISC): dietary assessment methods for 8- to 10-year-olds.

OBJECTIVES: The dietary assessment methods used in the Dietary Intervention Study in Children (DISC) are described and the rationale, validity, and/or general usefulness of each are discussed. DESIGN: DISC is the first multicenter, randomized, clinical trial to study the feasibility and long-term efficacy, safety, and acceptability of a fat-moderately diet in 8- to 10-year-old prepubescent children with moderately elevated plasma low-density lipoprotein cholesterol (LDL-C) levels. Final data collection for the original study (DISC I) occurred December 1, 1993; continued intervention and follow-up (DISC II) will extend beyond 1997. SETTING: Six clinical centers across the country participate in DISC. SUBJECTS: Preadolescent boys and girls with fasting LDL-C levels between the 80th and 98th age-specific and sex-specific percentiles established by the Lipid Research Clinics were eligible for the study. The feasibility phase included 140 children who were then enveloped into the full-scale trial. Baseline dietary data for 652 randomized children in the full-scale trial and 6-month results for the feasibility cohort are reported. INTERVENTIONS: Dietary assessment involved several elements: (a) determining eligibility based on consumption of more than 30% of energy from total fat, (b) monitoring adherence to and adequacy of the intervention diet, (c) evaluating acceptability of the diet in the intervention group, and (d) determining appropriate foods for the intervention diet. Methods are described for each purpose. MAIN OUTCOME MEASURES: LDL-C differences between the two groups and differences in total and saturated fat intakes as calculated from three 24-hour recalls were the primary outcome measures. Six-month dietary differences in the feasibility group are reported. STATISTICAL METHODS: Baseline group means and 6-month differences in dietary intake are reported for the full-scale trial and feasibility study, respectively. RESULTS: Baseline mean intake from three dietary recalls for the intervention (n = 328) and control (n = 324) groups, respectively, were as follows: energy = 1,759 kcal and 1,728 kcal; total energy from fat = 33.3% and 34.0%; total energy from saturated fat = 12.5% and 12.7%; and total dietary cholesterol = 209 mg and 195 mg. After 6 months of intervention, percentage of energy from total fat and saturated fat was reduced by 5.1% (P = .004) and 2.9% (P < .001), respectively, in this feasibility subset (n = 73) of the intervention group. Essentially no change in these parameters occurred in the control group (n = 67), which demonstrates a measurable difference in reporting between groups. APPLICATIONS/CONCLUSIONS: Results illustrate the feasibility of implementing a variety of dietary assessment methods among preadolescent children without relying primarily on parental reports.

Primary care physicians and children's blood cholesterol.

BACKGROUND. In a national survey sponsored by the National Heart, Lung, and Blood Institute, 62% of primary care physicians of children (under age 18 years) believed that high levels of low-density lipoprotein cholesterol in childhood had a great effect on subsequent heart disease risk. RESULTS. About 75% believed high blood pressure, smoking, and diabetes had similar effects. Although routine cholesterol screening in children under age 10 was infrequent, 72% of physicians screened high risk children. The age at which screening was done varied markedly; more pediatricians screened children younger than 5 years. The majority of physicians who saw children with high blood cholesterol instituted nondrug therapy, with pediatricians being most apt to do so. Low saturated fat diets were prescribed by 26% of these physicians and 9% of physicians prescribed increased polyunsaturated diets. Twelve percent of physicians treating hypercholesterolemic children used lipid-lowering drugs. Among those using drugs, 9% based drug use on total blood cholesterol measurements only. Factors that affected physician treatment of childhood hypercholesterolemia included physician specialty type, organization of practice (group or solo), and the age distribution of the pediatric patient population.