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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.

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.

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)

Parent-child associations of height, weight, subscapular skinfold thickness, blood pressure, and serum lipids and lipoproteins were observed in a cohort of 440 infants and their parents in Bogalusa, LA. The infants were examined according to a standardized protocol six times from birth to 7 years of age, and the parents were examined when the child was 2 years old. Regression analyses were performed with the value of the cardiovascular risk factor variable for the child as the dependent variable and race, sex of child, and either mother's value, father's value, or both mother's and father's values as the independent variables. The most significant relationship between parents and their children was for height (P < .005 at all ages of the child) and weight (P < .05 from age 1 year for father's regression coefficient and at all ages for mother's regression coefficient). Regression coefficients for parental serum lipids and lipoproteins tended to increase with the child's age. Child-father regression coefficients and child-mother regression coefficients were generally significant (P < .05) after age 2 years for total cholesterol. Less association was noted for triglycerides and lipoproteins. Parental diastolic BP was a poor predictor of children's values; the regression coefficients for systolic BP were higher and more significant. The longitudinal nature of this cohort study allows for examination of the changing patterns of familial association with aging and may provide insight as to the best age for examining children for cardiovascular risk factors to determine their relative risk for heart disease.

The "Report of the National Heart, Lung, and Blood Institute's Task Force on Blood Pressure Control in Children" (Pediatrics suppl, May 1977) is a serious and long-needed attempt at establishing guidelines for practitioners in monitoring blood pressure levels in children and diagnosing early primary hypertension. Further, and importantly, it includes a consideration of prevention of future hypertensive disease, encouraging greater research and clinical interest in blood pressure in the pediatric age group. Specifically it encourages the physician examining children to include observations of blood pressure as a routine part of a physical examination.

Height, weight, and skinfold measurements were obtained on a cohort of 447 children from birth (weight) or 6 months of age (height and skinfold) and monitored yearly thereafter until 7 years of age. At age 7 years, 250 remained for follow-up screening. A significant degree of tracking was found for all variables from age 1 to age 7 years. Height and weight tracked most strongly (age 1- to 7-year correlations = .42 and .44, respectively), whereas skinfold tracked somewhat lower (.28). Earlier levels of each anthropometric variable were the best predictor of later levels of that parameter. Implications for early detection and treatment of growth abnormalities are discussed.

Cardiovascular risk factor variables were examined in a cohort of 440 infants from birth through 7 years of age. Anthropometric measures, BP, serum lipid and lipoprotein values, and dietary intake data were obtained according to detailed protocols. Various quality controls to ensure the collection of valid and reliable data were instituted. Participation remained high throughout the study with 80% of the children examined at 6 months and 60% at 7 years of age. Rates were slightly higher for black than for white children. Children born in the private hospital were more likely to continue in the study than children born in the charity hospital. Children of parents examined when the child was 2 years of age were more likely to be examined during the preschool phases, but parental examination was not related to child examination when the child was 7 years of age. As in studies of school-aged children, measurement errors were lowest for height, weight, and serum total cholesterol. Measurement errors for BP were highest at the younger ages, particularly for diastolic BP. Examination of a newborn cohort throughout time affords the opportunity to study early development of relationships and tracking of cardiovascular risk factors.

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.

Dietary patterns and racial differences in nutrient intake were observed in children 6 months to 4 years of age in the Bogalusa Heart Study. Even in this sample of young children, the composition of the intakes of the majority of children was not compatible with prudent recommendations of less than 35% and 10% of energy from total and saturated fat, respectively. Mean cholesterol intake of the 4-year-old children (390 mg) was approximately one half of the average daily adult levels. The polyunsaturated to saturated fatty acid ratio ranged from 0.41 to 0.53 and sucrose to starch ratio from 1.32 to 1.57, reflecting a high saturated fat and sucrose intake. White children had greater intakes of sucrose than black children; however, total fat and cholesterol intakes were greater in black children. Gender differences were noted among the 2, 3, and 4-year-old children: energy, sugar, and starch intakes were greater in boys, and cholesterol intake per 1,000 kcal was greater in girls. Mean intakes per 1,000 kcal in Bogalusa were higher for fat and carbohydrate and lower for protein than reported in the Second Health and Nutrition Examination Survey. However, when the National Research Council recommended dietary allowances for protein and energy are used for comparison, a more than adequate intake was noted in these children. The data found in this newborn-infant cohort contribute information regarding the early development of dietary habits that likely influence eating behavior in later childhood and adolescence.

Serum lipids and lipoprotein cholesterol fractions were examined in a newborn cohort that was followed from birth to 7 years of age. Although white and female infants had higher cord blood levels of high-density lipoprotein cholesterol (HDL-C) than did black and male infants, respectively, these differences did not persist throughout early childhood. Mean levels of all serum lipids and lipoproteins increased greatly in the first 6 months of life, and by 2 years of age, levels approached those seen in adolescents. Infants consuming cow's milk had higher 6-month levels of serum total cholesterol and low-density lipoprotein cholesterol than did formula-fed infants. However, milk source in infancy did not significantly influence total cholesterol or low-density lipoprotein cholesterol levels at age 7 years. Serum lipid and lipoprotein levels at age 7 years were associated with previously measured levels as early as 6 months of age, and infants with unfavorable levels were likely to have similar adverse levels at 7 years of age. In addition, increases in obesity between 6 months and 7 years of age were positively associated with increases in levels of serum triglycerides. These results suggest that certain persons at increased risk for cardiovascular disease can be identified in infancy.

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