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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.

BACKGROUND Adiponectin, an adipocytokine with beneficial biological functions relevant to cardiovascular (CV) diseases, and arterial stiffness, an indicator of vascular function, are considered to be important correlates of CV disease risk. Although racial (black-white) divergences in adiponectin and arterial stiffness are known, information is scant regarding the association between these two parameters among asymptomatic young adults within each race. METHODS As part of the Bogalusa Heart Study, arterial stiffness was examined noninvasively in terms of aorta-femoral pulse wave velocity (af-PWV) in 991 black and white nondiabetic subjects (72% white, 43% male) aged 24-44 years. RESULTS In a multivariate regression model by race that included adiponectin, age, sex, waist circumference, mean arterial pressure, heart rate, homeostasis model assessment of insulin resistance, low- and high-density lipoprotein cholesterols, triglycerides, and cigarette smoking, the significant predictors of af-PWV, in the order of entry, were: mean arterial pressure, age, smoking, and heart rate in both races, followed by adiponectin (inverse relation) in blacks. Further, after adjusting for mean arterial pressure, age, smoking, and heart rate, the odds ratio of finding excess af-PWV (top decile vs. the rest) in individuals with low adiponectin levels (bottom quartile vs. the rest) was significantly higher in blacks (OR: 2.5; 95% CI: 1.1-5.5), but not in whites (OR: 0.9; 95% CI: 0.5-1.9). CONCLUSIONS These findings suggest that the status of hypoadiponectinemia is an independent correlate of excess arterial stiffness in asymptomatic young black adults.

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.

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.

Between the years 1979 and 1981, Louisiana ranked 7th in average annual coronary heart disease (CHD) death rate among white women and 6th among black women, age 35 to 74 years. Nationally, death in women due to CHD is 250,000 deaths per year, mainly in women over 50 years of age. That is approximately one half of all deaths due to heart disease in the United States. Risk factors for CHD in women are those which are shared with men, eg, smoking, hypertension, plasma lipoprotein concentrations, obesity, diabetes, and family history, and those which apply solely to women, eg, contraceptive use, menopause, and postmenopausal hormones. The purpose of this manuscript is to review current knowledge regarding CHD in women.

The robust or model-free method for detecting linkage developed by Haseman and Elston for data from sib pairs is extended to incorporate observations of multiple traits on each individual. A method is proposed that estimates the linear function that results in the strongest correlation between the squared pair differences in the trait measurements and identity by descent at a marker locus. The method is illustrated by the study of apolipoprotein and cholesterol levels in individuals from a large family that had many members diagnosed with coronary heart disease.

We separately evaluated split specimens of serum for lipoprotein cholesterol in 38 five- to 14-year-old children, by the heparin/Ca2+ precipitation method and the ultracentrifugation/dextran sulfate precipitation method. Statistical analysis of the results indicated an excellent agreement (especially in beta- and alpha-lipoprotein cholesterol values) between results by the two methods. The percentage of alpha-lipoprotein cholesterol (mean +/- SD: 38.6 +/- 5.0) in children further confirmed the earlier observations that cholesterol derived from alpha-lipoprotein in children constitutes a relatively greater part of the serum total cholesterol than is true of adults.

We evaluated glycosylation of hemoglobin (HbA + HbA1) in 25 control subjects and in 133 diabetic patients who were in various stages of blood glucose control, by measuring ketoamine-linked hexoses in hemoglobin. These hexoses were converted by digestion with 10 mol/L acetic acid for 16 h at 100 +/- 5 degrees C to 5-hydroxymethylfurfuraldehyde, which was quantitated by reaction with 2-thiobarbituric acid. Glycosylation of hemoglobin was expressed as micromoles of hydroxymethylfurfuraldehyde per gram of globin protein (the "HMF index"). A mean HMF index of 1.67 (SD = 0.23) was obtained for controls; that for diabetic patients was 2.93 (SD 0.95). The index correlated well (r = 0.83, p < 0.001) with average blood glucose concentration as measured during the preceding 16 weeks, over a wide range of glucose values (1 to 6 g/L). It correlated even better (r = 0.92, p < 0.001) when corrected for variations in hemoglobin concentration. Thus measurement of ketoamine-linked hexoses of hemoglobin or HMF index provides an independent and useful alternative to the currently used methods that measure only HbA1 or HbA1c.

We studied the effect of low-density lipoproteins (LDL) on the synthesis and secretion of proteoglycans by cultured human umbilical-vein endothelial cells. Confluent cultures were incubated with [35S]sulphate or [3H]glucosamine in lipoprotein-deficient serum in the presence and in the absence (control) of LDL (100-400 micrograms/ml), and metabolically labelled proteoglycans in culture medium and cell layer were analysed. LDL increased accumulation of labelled proteoglycans in medium and cell fractions up to a concentration of 200 micrograms/ml. At this concentration of LDL the accumulations of proteoglycans in medium and cell layer were 65% and 32% respectively above control for 35S-labelled proteoglycans, and 55% and 28% respectively above control for 3H-labelled proteoglycans. At concentrations above this LDL was found to depress the accumulation of proteoglycans in medium and cell layer. Gel filtration on Sepharose CL-4B showed that in both control and LDL-treated cultures the cell layer contained a large (Kav. = 0) and a small (Kav. = 0.35) heparan sulphate proteoglycan, whereas the culture medium contained a large heparan sulphate proteoglycan (Kav. = 0) and a smaller isomeric chondroitin sulphate proteoglycan (control, Kav. = 0.35; LDL-treated, Kav. = 0.17). The relative increase in hydrodynamic size of the isomeric chondroitin sulphate proteoglycan (Mr 150,000 compared with 90,000) in the medium of cultures exposed to LDL was partly attributable to the larger size of the glycosaminoglycan side chains (Mr 39,000 compared with 21,000). The isomeric chondroitin sulphate proteoglycan in LDL-treated culture was relatively enriched in chondroitin 6-sulphate compared with that in control cultures (39% compared with 29%). Pulse-chase studies showed that LDL treatment did not alter the turnover rate of proteoglycans as compared with controls, implying that the elevation in proteoglycan accumulation in LDL-treated cultures was due to enhanced synthesis. These results demonstrate that LDL can modulate proteoglycan synthesis by cultured vascular endothelial cells, resulting in the secretion of a larger isomeric chondroitin sulphate proteoglycan enriched in chondroitin 6-sulphate.

The concept of injury as a mechanism leading to atherosclerosis has been fostered by numerous studies of initiating factors and by observation of the response of cardiovascular connective tissue, ie, cellular and extracellular matrix components. Carbohydrate-protein macromolecules of the extracellular matrix are a complex group of biologically important substances that play a crucial role in mesenchymal tissue repair following injury, a process needed to maintain arterial wall integrity. Of particular interest are the proteoglycans that enter into a variety of roles, from that of inhibiting atherosclerosis and helping to maintain fibrillar structures to that of taking part in lipid deposition in the development of atherosclerosis.

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.

A self-administered rating scale was developed to assess type A behavior in children. It contains 24 items (7-point scale) thought to reflect the major components of type A behavior. The scale was judged to be reliable and yielded the following factors: eagergy (eagerness-energy), restlessness-aggression, leadership, and alienation. 6 tasks were designed (reading, eating, walking, competition, time estimation, and crossing out number) to validate this new measure. A total of 160 predominantly middle-class public school fifth- and sixth-grade children participated in the following factorial design: 2 (classification-type A and type B) X 2 (condition-control and experimental) X 2 (sex-male and female) X 2 (race-white and black). Type A children performed in a more accelerated or intense manner than did type B children on 5 of the 6 tasks (only females exhibited rapid time estimation) as predicted. Also, children performed in a more accelerated or intense manner if they task instructions emphasized speed or intensity for 3 of the tasks (reading, crossing out number, and walking measures). Sex and race differences are also reported. Partial support is provided for the validity and reliability of this new measure.

Two proteoglycan-hyaluronate complexes were extracted from bovine aorta with 4.0 M guanidinium chloride in the presence of protease inhibitors and purified by cesium chloride density gradient centrifugation under associative conditions. Complex I with higher buoyant density had 22% protein and 18% uronate, whereas Complex II had 11% protein and 23.6% uronate. Glycosaminoglycan (GAG) analysis of the complexes indicated that both complexes contained large amounts of hyaluronic acid, 13.6% and 24.0% of the total GAG in Complexes I and II, respectively. Chondroitin sulfates and dermatan sulfate constituted the remainder of the GAG. Chromatography on Sepharose CL 6B suggested that Complex I had an estimated molecular weight of 800,000 and Complex II, 250,000. The complexes were dissociated into proteoglycan and hyaluronate by cesium chloride density gradient centrifugation under dissociative conditions. The proteoglycans free of hyaluronic obtained from the complexes had similar protein and GAG composition. The molecular weight of the proteoglycan was estimated to be 80,000 and that of the hyaluronate of the complex, 90,000.

Proteoglycans were extracted from bovine lung gas exchange tissue, pleura, and bronchioles with 4.0 M guanidinium chloride at 5 degrees C in the presence of protease inhibitors. Preliminary purification of the proteoglycans was achieved by an initial CsCl isopycnic centrifugation (rho 0 = 1.33) and through precipitation with cetylpyridinium chloride in 0.5 M KCl. Further purification and fractionation of proteoglycans was achieved by a second CsCl isopycnic centrifugation (rho 0 = 1.45) in 4.0 M guanidinium chloride. Based on the ultracentrifuge profiles and electrophoretic behavior, the major fractions were pooled. They were purified further by gel filtration on Sepharose CL-2B and characterized by extensive analyses. A heparan sulfate proteoglycan was the major proteoglycan identified in the gas exchange tissue and in the pleura. The major proteoglycan component from the bronchioles was a chondroitin sulfate proteoglycan. Approximate molecular weight of 2 x 10(6) for the heparan sulfate proteoglycan from the pleura and chondroitin sulfate proteoglycan from the bronchioles and 1 x 10(6) for the heparan sulfate proteoglycan from the gas exchange tissue were estimated from gel filtration analyses. After incubation with hyaluronic acid, the chondroitin sulfate proteoglycans from the bronchioles showed an increase in specific viscosity and a higher molecular weight compound eluting near the void volume in Sepharose CL-2B column chromatography. The proteoglycans exhibited varied anticoagulant activities in Stypven, partial thromboplastin and thrombin clotting times and inhibited thrombin-induced platelet aggregation.

The interactions of a chondroitin sulfate-dermatan sulfate proteoglycan with serum very low (VLDL), low (LDL), and high density (HDL3) lipoproteins were studied with special reference to the nature of the interaction of LDL and the proteoglycan. The proteoglycan formed insoluble complexes with VLDL and LDL, but no complex was formed with HDL3. The proteoglycan (40 micrograms/ml) converted 98% of added LDL (150 micrograms of cholesterol/ml) into insoluble complex at a Ca2+ concentration of 30 mM. Physiologic concentrations of albumin inhibited insoluble complex formation with VLDL and LDL by 61.5 and 40.7%, respectively. The proteoglycan formed soluble complexes with LDL even in the absence of Ca2+. Optimum soluble complex formation occurred when the medium contained 66.6 micrograms of proteoglycan and 166.6 micrograms of LDL cholesterol/ml. Specific modifications of the lysine and/or arginine residues of LDL prevented complex formation with the proteoglycan, thus indicating the requirement of the positive charges of the protein moiety of LDL in the interaction. Removal of the protein core or the glycosaminoglycan chains of the proteoglycan prevented interaction with LDL. Desulfation of the proteoglycan molecule also inhibited complex formation with LDL. Thus, the native state of the arterial proteoglycan molecule confers optimum charge density for specific interaction with serum apoprotein B-containing lipoproteins.