Lipoprotein subfractions by ion mobility in lean and obese children

OBJECTIVE

To establish normative data for lipoprotein subfractions using a novel ion mobility assay in healthy lean children and to compare their data with those of obese children preselected with normal glucose, blood pressure, and relatively normal lipids.

STUDY DESIGN

Fasting blood samples in 162 children aged 7.0-18.9 years (75 lean [body mass index: 18.6 ± 6.6 kg/m(2)] and 87 obese [body mass index: 31.7 ± 5.4 kg/m(2)]) were analyzed. Correlation of lipoprotein subfractions with anthropometric and laboratory markers was performed. Principal component analysis was used to avoid using correlated variables.

RESULTS

Normative data for lipid subfractions were obtained in healthy children. Lean children had higher high-density lipoprotein (HDL)-large (76%), HDL-small (13%), and HDL-total (27%) compared with obese (P < .01), and lower low-density lipoprotein (LDL)-medium (-30%, P < .01) and medium + small (-21%, P = .02) as well as LDL-total (-13%, P = .035). In both groups, the LDL component was higher in males and pubertal children (P < .01). Prepubertal children had a higher HDL component than pubertal ones (P < .004). Adjusting for sex and pubertal status LDL component was positively, and HDL component negatively, correlated with obesity (P < .004).

CONCLUSIONS

Despite relatively normal triglycerides and cholesterol measured with standard assays at screening, ion mobility analysis showed significant differences in lipid and apolipoprotein subfractions between lean and obese children, even those prepubertal. Long-term, prospective follow-up may better characterize the predictability of lipid subfractions for future cardiovascular disease risk in children.

Associations between a parental history of premature cardiovascular disease and coronary artery calcium and carotid intima-media thickness: the Coronary Artery Risk Development In Young Adults (CARDIA) study

BACKGROUND

It is unclear if associations between a parental history of premature CVD (pCVD) and subclinical atherosclerosis are attenuated by adjustment for long-term risk factor levels through middle adulthood.

DESIGN

Prospective community-based cohort study.

METHODS

CARDIA participants who attended the year-20 exam (n = 2283, mean age 45 years) were grouped by pCVD status: maternal only, paternal only, any parental, and no parental history (referent). We used separate logistic regression models, adjusted for average risk factor levels over a 20-year follow up to assess associations of parental pCVD and subclinical atherosclerosis in offspring.

RESULTS

White participants with any parental history of pCVD had a higher odds of coronary artery calcium (CAC) >0 than participants with no parental history (OR 1.55, 95% CI 1.01-2.37). This was largely driven by the association of a paternal history of pCVD with CAC >0 (OR 2.15, 95% CI 1.42-3.23), which was minimally attenuated by multivariable adjustment (OR 2.09, 95% CI 1.31-3.32). Similarly, adjusted associations between parental pCVD and intima-media thickness (IMT) >90% were observed in white participants with a paternal history of pCVD (OR 1.93, 95% CI 1.10-3.39) and any parental history pCVD (OR 1.67, 95% CI 1.02-2.74). No significant associations between a parental history of pCVD and the odds of subclinical atherosclerosis were observed in black participants.

CONCLUSIONS

Parental pCVD is independently associated with early development of subclinical atherosclerosis; these associations may be race-specific for participants in their fifth decade of life.

Plasma lipid concentrations in nondiabetic African American adults: associations with insulin resistance and the metabolic syndrome

Despite higher rates of cardiovascular disease, African Americans have a more favorable lipid profile. The purpose of the study was to examine the association between plasma lipid concentrations and insulin resistance in African Americans and to determine if insulin resistance is present at a lower triglyceride (TG) threshold than is used for metabolic syndrome criteria. Data were examined on 185 nondiabetic African American men (n = 61) and women (n = 124), mean age, 39.8 years. Measurements included blood pressure, anthropometrics, oral glucose tolerance test, and insulin sensitivity (M) by insulin clamp. The relationship between lipids and insulin sensitivity was analyzed by correlation analysis and by comparing TG levels among tertiles of M. Despite relatively low mean (+/- SD) TG level (87.8 +/- 55.2 mg/dL), there were statistically significant correlations of M with TG (r = -0.23, P < .002), high-density lipoprotein cholesterol (HDL-C; r = 0.19, P < .01), and TG/HDL-C ratio (r = -0.23, P < .002). The correlations were strongest in men. Subjects with TG in an intermediate range (110-149 mg/dL) had insulin resistance equivalent to that of the high-TG group (>/=150 mg/dL). In African Americans, TG levels below the current metabolic syndrome threshold criterion are associated with insulin resistance.

Effect of obesity and high blood pressure on plasma lipid levels in children and adolescents

OBJECTIVE

To examine the extent of blood lipid abnormalities in overweight children and to determine whether the prevalence of dyslipidemia is different in overweight children with elevated blood pressure (BP) compared with overweight children with normal BP (NBP).

METHODS

A retrospective, case-control study on 497 patients 2 to 18 years of age at the Nemours Weight Management Clinic of duPont Hospital for Children was conducted to compare the prevalence of abnormal plasma lipid levels in overweight children with high BP with overweight children with NBP.

RESULTS

Elevated BP was detected in 34.7% of the sample; 27.9% had prehypertension (pre-HTN), and 6.8% had HTN. The rates of abnormal plasma lipid levels were high among overweight children with both NBP and HTN. Significantly more boys with high BP had low high-density lipoprotein cholesterol compared with boys with NBP (49.4% vs 27.6%). Significantly more severely obese boys had low high-density lipoprotein cholesterol compared with moderately obese boys (40.3% vs 29.3%). The prevalence of elevated BP was much greater in severely obese boys and girls (46.5% and 39%) than moderately obese boys and girls (28.1% and 23.1%).

CONCLUSIONS

The high prevalence of dyslipidemia found in this overweight sample supports recent recommendations to collect plasma lipid levels in not only overweight children with BP > or =90th percentile but also in all overweight children.

Lifestyle-only intervention attenuates the inflammatory state associated with obesity: a randomized controlled study in adolescents

OBJECTIVES

The primary goals were to understand the relationship among the inflammatory factors, C-reactive protein (CRP), interleukin-6 (IL-6), and fibrinogen, and indices of obesity in normoglycemic, insulin-resistant adolescents and to investigate the impact of a lifestyle-only intervention on these nontraditional risk factors for cardiovascular disease (CVD).

STUDY DESIGN

Randomized controlled lifestyle-only intervention study in adolescents. Of the 21 adolescents studied, 15 obese subjects (body mass index [BMI] = 37.6 +/- 3.3 kg/m 2 ) were randomized to either a lifestyle intervention program or usual care. The lean controls were studied only at baseline. Analysis of variance (ANOVA) for repeated measures was used to study intervention effect and t test, one-way ANOVA, and discriminant function analysis for baseline comparisons.

RESULTS

The intervention group maintained weight, whereas the control group gained weight (P = .02). A redistribution of body composition and a decrease in insulin resistance were observed. Elevated circulating concentrations of CRP, fibrinogen, and IL-6 were significantly reduced (all P <or=.02) in response to intervention, but not in controls.

CONCLUSIONS

Modest lifestyle-only change in previously sedentary obese adolescents redistributes the parameters of body composition in the absence of weight loss and reverses, at least in part, the inflammatory state in association with an improvement of insulin resistance.

Dysmetabolic syndrome: multiple risk factors for premature adult disease in an adolescent girl

The clinical diagnosis of dysmetabolic syndrome in an adult defines a patient with abnormal glucose metabolism (or diabetes), hypertension, hyperlipidemia, and obesity. This disorder accelerates atherosclerosis and significantly raises the risk for cardiovascular events. With the marked rise in the prevalence of obesity in childhood, obesity-linked risk factors are being expressed at young ages. The case of a 12-year-old girl with dysmetabolic syndrome is described and discussed. Emerging clinical data now indicate that the presence of 1 risk factor for cardiovascular disease in an overweight child should prompt screening for additional clinical abnormalities, with the aim of finding treatable disorders.

The association between hypertension and other cardiovascular risk factors in young adult African Americans

Hypertension is a major cause of cardiovascular disease in African Americans. The excess morbidity and mortality due to cardiovascular disease in African Americans compared to Caucasians is not well explained. The purpose of this study was to examine the association between hypertension and other cardiovascular risk factors in young adult African Americans. A risk factor scoring system was developed, based on national guidelines for obesity, smoking, cholesterol levels, glucose tolerance, and blood pressure. Data from a previously studied cohort of 206 women and 117 men were analyzed for the association of hypertension with other risk factors. Among women, risk factor intensification is due to impaired glucose tolerance and obesity. Among men, intensification appears to be related to all major risk factor categories. These findings indicate that among hypertensive African Americans there is an amplification of other risk factors. The data also support the clinical management of multiple risk factors as well as the achievement of blood pressure control.

A cholesterol-lowering diet does not produce adverse psychological effects in children: three-year results from the dietary intervention study in children

The Dietary Intervention Study in Children (DISC), a 2-arm, multicenter intervention study, examined the efficacy and safety of a diet lower in total fat, saturated fatty acids, and cholesterol than the typical American child's diet. A total of 663 8- to 10-year-old children with elevated low-density lipoprotein cholesterol levels were randomly assigned to either an intervention or a usual-care group. Intervention included group and individual counseling sessions to assist participants in adopting a dietary pattern containing 28% or less of calories from total fat (<8% as saturated fat, up to 9% as polyunsaturated fat, and 11% as monounsaturated fat) and dietary cholesterol intake of less than 75 mg/1,000 kcal. The dietary intervention reduced low-density lipoprotein cholesterol levels, and 3-year results showed no adverse effects for children in the intervention group in terms of academic functioning, psychological symptoms, or family functioning.

A cholesterol-lowering diet does not produce adverse psychological effects in children: three-year results from the dietary intervention study in children

The Dietary Intervention Study in Children (DISC), a 2-arm, multicenter intervention study, examined the efficacy and safety of a diet lower in total fat, saturated fatty acids, and cholesterol than the typical American child's diet. A total of 663 8- to 10-year-old children with elevated low-density lipoprotein cholesterol levels were randomly assigned to either an intervention or a usual-care group. Intervention included group and individual counseling sessions to assist participants in adopting a dietary pattern containing 28% or less of calories from total fat (<8% as saturated fat, up to 9% as polyunsaturated fat, and 11% as monounsaturated fat) and dietary cholesterol intake of less than 75 mg/1,000 kcal. The dietary intervention reduced low-density lipoprotein cholesterol levels, and 3-year results showed no adverse effects for children in the intervention group in terms of academic functioning, psychological symptoms, or family functioning.

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.

Relationship of cardiovascular risk factors to echocardiographic left ventricular mass in healthy young black and white adult men and women. The CARDIA study. Coronary Artery Risk Development in Young Adults

BACKGROUND

The objective of this study was to describe the distribution of echo left ventricular (LV) mass and its association with demographic and cardiovascular risk factors in a large race- and sex-balanced cohort of young adults. Recent epidemiological data have suggested that M-mode echocardiographically determined LV hypertrophy is an independent predictor of mortality and morbidity from coronary heart disease (CHD) in older adults. Echocardiographic LV mass has been associated in middle-aged and older adults with multiple factors including age, arterial blood pressure, body mass, and sex. However, there are few data describing the distribution of echo LV mass among black and white young adult men and women and relating LV mass to cardiovascular disease risk factors within race-sex subgroups.

METHODS AND RESULTS

CARDIA (Coronary Artery Risk Development in Young Adults) is a multicenter study of young adults, including approximately equal proportions of black and white men and women aged 23 to 35 years at the time of echo examination (1990 through 1991). Two-dimensionally guided M-mode echocardiograms were attempted in 4243 participants with recordings deemed acceptable for calculation of LV mass, that is, of at least fair quality score, obtained in 3840 (90.5% of the 1990-1991 cohort). M-mode LV mass was calculated from the formula of Devereux and Reicheck, adapted for use with measurements made according to the American Society of Echocardiography Standards. LV mass was greater in men than in women and greater in blacks than in whites (P < .001) (mean +/- SD): black men, 176 +/- 42 g; white men, 169 +/- 40 g; black women, 135 +/- 38 g; and white women, 125 +/- 33 g. In all race-sex groups, LV mass was positively correlated (P < .0001) in bivariate analyses with body weight, subcapular skinfold thickness, height, and systolic blood pressure. In multivariate analyses, LV mass remained independently and positively related to body weight and systolic blood pressure and, when body weight was not considered, with subcapular skinfold thickness and height. In addition, the multivariate models allowed us to infer a direct relation between LV mass and both fatness and lean body mass. Weaker positive associations were noted of LV mass with pulse pressure in white participants and with physical activity in men. After adjustment for subscapular skinfold thickness, height, systolic and diastolic blood pressures, alcohol consumption, pulmonary function, smoking history, physical activity, total serum cholesterol, and family history of hypertension, LV mass remained higher in men than in women (P < .0001), in black men (167 +/- 43 g) than in white men (156 +/- 50 g, P < .0001), and in black women (142 +/- 49 g) than in white women (137 +/- 43 g, P < .002).

CONCLUSIONS

In the healthy young adults of the CARDIA cohort, LV mass was highly correlated with body weight, subscapular skinfold thickness, height, and systolic blood pressure across race and sex subgroups. Furthermore, after adjustment for anthropometric, blood pressure, and other covariates, LV mass remained higher in men than in women and in blacks than in whites. Longitudinal studies are necessary to delineate the possible roles of these factors in the genesis of LV hypertrophy.

Echocardiographic left ventricular systolic function and volumes in young adults: distribution and factors influencing variability

Low left ventricular ejection fraction (LVEF), a measure of global systolic left ventricular dysfunction, is associated with an increased risk of recurrent coronary events or death in persons with cardiac disease. There are few data on the distribution of resting LVEF and component volumes in healthy young adults or on any association of LVEF with coronary risk factors. LVEF and left ventricular end-diastolic and end-systolic volumes (LVEDV and LVESV, respectively) were measured by two-dimensional echocardiography in 1782 men and women 23 to 35 years old without self-reported heart disease (other than mitral valve prolapse, n = 53) who were participants in the multicenter Coronary Artery Risk Development in Young Adults study. Factors analyzed as potential contributors to LVEF, LVEDV, and LVESV included age, gender, race, blood pressure, alcohol use, current smoking, family history of myocardial infarction, total and high-density lipoprotein cholesterol concentrations, obesity, reported physical activity, and fitness as assessed by treadmill exercise testing. LVEF was lower in men (mean 62.6% SD 5.7%) than in women (mean 63.9%, SD 5.7%) (p < 0.01) but did not differ significantly between black and white subjects. Ninety percent of subjects had an LVEF between 53% and 71%. LVEDV and LVESV were > 25% greater in men than in women. From multivariate analysis, male gender, history of hypertension, and current smoking were each positively and independently associated with an approximately 1% lower LVEF. Body surface area, a family history of premature myocardial infarction, and treadmill workload 150 time were positively related, whereas total skinfold thickness was negatively related to LVEDV and LVESV.(ABSTRACT TRUNCATED AT 250 WORDS)

Peripheral gangrene associated with Kawasaki disease

Three American infants with Kawasaki disease (KD) complicated by peripheral extremity gangrene are reported. Eight such patients (only 1 from Japan) have been reported previously. These 11 patients, infants less than 7 months old at onset of KD, are predominantly non-Asian. At least nine had associated giant coronary aneurysms, and eight had associated peripheral arterial aneurysms. In eight infants the diagnosis of KD was not established and therapy was not instituted until greater than or equal to 14 days after onset. Peripheral ischemia initially was noted 15-31 days after onset. Although the pathogenesis of this complication is not well understood, it likely includes some combination of local peripheral arteritis, arteriospasm, thrombosis peripherally and/or more proximally (e.g., in an axillary artery aneurysm), and cardiogenic shock. Treatment may include use of antiinflammatory agents such as salicylates and intravenous gamma globulin, vasodilative agents and/or methods, and thrombolytic and/or anticoagulant agents in an attempt to prevent the potentially devastating consequences of progressive gangrene.