Increased Serum Cholesteryl Ester Transfer Protein in Obese Children

Objective: To determine whether serum cholesteryl ester transfer protein (CETP), which is one of the physiologically active gene products secreted from adipose tissue, is increased and associated with atherogenic lipoprotein profile in obese children. Research Methods and Procedures: Subjects were 42 consecutive outpatient Japanese obese children, 29 boys and 13 girls, ranging in age from 5 to 14 years, and 25 age‐matched non‐obese children, 13 boys and 12 girls, as the control group for measuring CETP mass. Blood was drawn after an overnight fast and, at the same time, and anthropometric measurements including height, body weight, waist girth, hip girth, and triceps and subscapular skinfold thicknesses were taken. Paired samples were obtained from 15 obese children who underwent psychoeducational therapy. Serum CETP mass was assayed by an enzyme‐linked immunosorbent assay. Results: The serum levels of triglyceride, total cholesterol (TC), low‐density lipoprotein cholesterol, TC/high‐density lipoprotein cholesterol (HDLC), apolipoproteins (apo) B, apo B/apo A₁, and insulin in obese children were significantly higher than the respective reference values. Serum CETP level was ～2‐fold higher (98.7 ± 3.6 vs. 50.9 ± 4.0 nM, means ± SEM, p < 0.001) in the obese children than in the controls. In 15 obese children, whose percentage of overweight declined during therapy, CETP levels decreased significantly. CETP level was correlated with HDLC, TC/HDLC, and insulin, and with percentage of overweight when the data of the obese and non‐obese children were combined. Discussion: CETP is increased and associated with the atherogenic lipoprotein profile in obese children.     

Obesity in Spanish Schoolchildren: Relationship with Lipid Profile and Insulin Resistance

This article reports cross‐sectional data from a total of 1048 children, 6 to 8 years of age, categorized by presence or absence of obesity, who participated in a voluntary survey of cardiovascular risk factors in Spain over the period of 1998 to 2000, to establish the relationship between obesity and its metabolic consequences at this age. The prevalence of obesity and overweight were 9.4% and 15.7%, respectively, in boys and 10.5% and 18.0%, respectively, in girls. We observed that, in both sexes, obese children had higher triglycerides and lower high‐density lipoprotein‐cholesterol levels than non‐obese children. No differences were found in plasma glucose or low‐density lipoprotein‐cholesterol levels between normal and obese children. However, we observed that insulin levels and the homeostasis model assessment for insulin resistance were significantly (p < 0.001) higher in obese children of both sexes but that free fatty acid levels were lower in obese children than in nonobese children, with a statistical significance in girls (0.72 ± 0.30 vs. 0.61 ± 0.16 mEq/liter). In summary, our survey found some metabolic consequences of obesity similar to those found in adults (elevated triglycerides, insulin, and the homeostasis model assessment for insulin resistance, and lower high‐density lipoprotein‐cholesterol). However, other features (glucose, total cholesterol, low‐density lipoprotein‐cholesterol, and free fatty acid levels) were found to behave differently, indicating that the association of obesity with risk factors seems to change as the children age and may depend on the chronology of sexual maturation.     

Dehydroepiandrosterone sulfate and high-density lipoprotein-cholesterol levels in overweight children

Objective: The association of childhood overweight with cardiovascular risk factors seems to change by sex and age, which may indicate that hormonal status could be the cause of this different association. In this study, we analyzed the relationship of dehydroepiandrosterone sulfate (DHEA‐S) with the alterations associated with overweight by analyzing the influence of this hormone in the differences found in biochemical variables between normal‐weight and overweight prepubertal children. Research Methods and Design: The study included 684 6‐ to 8‐year‐old children (350 boys and 334 girls) categorized by the presence or absence of overweight, according to the age‐ and sex‐specific cut‐off points proposed for children. Lipid levels were determined by standard methods. DHEA‐S and insulin levels were measured by radioimmunoassay. Biochemical variables were compared between normal‐weight and overweight children by tertiles of DHEA‐S. Results: We observed that plasma high‐density lipoprotein‐cholesterol (HDL‐C) and apolipoprotein (apo)‐AI levels were significantly lower in overweight than in normal‐weight boys only in the highest tertile of DHEA‐S. No significant differences in plasma glucose levels, total cholesterol, low‐density lipoprotein‐cholesterol, or apo B were found between overweight and normal‐weight children in any DHEA‐S tertile. In a Spearman correlation analysis, we observed a significant and negative correlation for weight and BMI with HDL‐C and for weight and apo‐AI levels only in the highest tertile of DHEA‐S. Discussion: Our study showed that, in our prepubertal population, the association of overweight with decreased HDL‐C and apo‐AI levels was present only in boys within the highest levels of DHEA‐S, supporting the importance of hormonal influences on the association of metabolic alterations with overweight.     

Adolescent Sex Differences in Adiponectin Are Conditional on Pubertal Development and Adiposity

Objective: Adiponectin is an adipose tissue protein with important insulin‐sensitizing, anti‐inflammatory, and cardioprotective properties but is paradoxically lower in obese individuals. Sex differences in adiponectin have been reported in adults and adolescents but not in prepubertal children. In this study, we hypothesized that sex differences in adiponectin would develop during puberty and would be influenced by level of adiposity. Research Methods and Procedures: Adiponectin levels were measured in 1196 white and African‐American adolescents. Insulin resistance was estimated using the homeostasis model (HOMA‐IR). Demographic, developmental, and metabolic variables, including interactions with adiposity measurements, were evaluated for independent relationships with adiponectin levels. Results: Overall, adiponectin levels varied significantly by sex, race, adiposity, and puberty stage. Significant sex differences in adiponectin developed after the onset of puberty, particularly in lean adolescents. Adolescent boys had lower adiponectin levels in post‐puberty compared with pre‐puberty (p = 0.01) and had lower levels than girls in both puberty and post‐puberty (both p < 0.001), after adjusting for race, BMI z‐score, and natural logarithm‐(HOMA‐IR). Sex differences were also conditional on adiposity level, with significant sex differences among lean (p < 0.001) but not among non‐lean (p = 0.16) adolescents. Adiponectin levels in girls decreased more with increasing adiposity than in boys (p = 0.004), but only marginally so after standardizing for girls’ higher mean adiponectin level (p = 0.11). Discussion: Sex differences in adiponectin are dependent on both puberty stage and adiposity in adolescents, such that by post‐puberty, non‐lean boys exhibit the lowest levels of adiponectin.     

Metabolic Syndrome in Overweight and Obese Japanese Children

Objective: To determine the prevalence of and sex differences related to the metabolic syndrome among obese and overweight elementary school children. Research Methods and Procedures: Subjects were 471 overweight or obese Japanese children. Children meeting at least three of the following five criteria qualified as having the metabolic syndrome: abdominal obesity, elevated blood pressure, low high‐density lipoprotein‐cholesterol levels, high triglyceride levels, and high fasting glucose levels. Fasting insulin levels were also examined. Results: Japanese obese children were found to have a significantly lower prevalence (17.7%) of the metabolic syndrome than U.S. obese adolescents (28.7%, p = 0.0014). However, Japanese overweight children had a similar incidence (8.7%) of the metabolic syndrome compared with U.S. overweight adolescents (6.8%). Hyperinsulinemia in girls and abdominal obesity in boys are characteristic features of individual metabolic syndrome factors in Japanese children. Discussion: The prevalence of the metabolic syndrome is not lower in preteen Japanese overweight children than in U.S. overweight adolescents, although it is significantly lower in Japanese obese preteen children than in U.S. obese adolescents. Primary and secondary interventions are needed for overweight preteen children in Japan.     

Fat Depot‐specific Impact of Visceral Obesity on Adipocyte Adiponectin Release in Women

Our objective was to examine omental and subcutaneous adipocyte adiponectin release in women. We tested the hypothesis that adiponectin release would be reduced to a greater extent in omental than in subcutaneous adipocytes of women with visceral obesity. Omental and subcutaneous adipose tissue samples were obtained from 52 women undergoing abdominal hysterectomies (age: 47.1 ± 4.8 years; BMI: 26.7 ± 4.7 kg/m²). Adipocytes were isolated and their adiponectin release in the medium was measured over 2 h. Measures of body fat accumulation and distribution were obtained using dual‐energy X‐ray absorptiometry and computed tomography, respectively. Adiponectin release by omental and subcutaneous adipocytes was similar in lean individuals; however, in subsamples of obese or visceral obese women, adiponectin release by omental adipocytes was significantly reduced while that of subcutaneous adipocytes was not affected. Omental adipocyte adiponectin release was significantly and negatively correlated with total body fat mass (r = ?0.47, P < 0.01), visceral adipose tissue area (r = ?0.50, P < 0.01), omental adipocyte diameter (r = ?0.43, P < 0.01), triglyceride levels (r = ?0.32, P ≤ 0.05), cholesterol/high‐density lipoprotein (HDL)‐cholesterol (r = ?0.31, P ≤ 0.05), fasting glucose (r = ?0.39, P ≤ 0.01), fasting insulin (r = ?0.36, P ≤ 0.05), homeostasis model assessment index (r = ?0.39, P ≤ 0.01), and positively associated with HDL‐cholesterol concentrations (r = 0.33, P ≤ 0.05). Adiponectin release from subcutaneous cells was not associated with any measure of adiposity, lipid profile, or glucose homeostasis. In conclusion, compared to subcutaneous adipocyte adiponectin release, omental adipocyte adiponectin release is reduced to a greater extent in visceral obese women and better predicts obesity‐associated metabolic abnormalities.     

High childhood obesity in an Australian population

Objective: The objective was to determine the prevalences of overweight and obesity in regional Australian children and to examine the association between BMI and indicators of socioeconomic status (SES). Research Methods and Procedures: Regionally representative cross‐sectional survey of 2184 children, 4 to 12 years of age, was conducted, and the socio‐demographic characteristics of their parents from regional Victoria, Australia, 2003 to 2004, were obtained. Results: The prevalences of overweight and obesity were 19.3 ± 0.8% (proportion ± standard error) and 7.6 ± 0.6%, respectively, using international criteria, and the proportion of overweight/obese girls was significantly higher than that of boys (29.6 ± 1.4% vs. 23.9 ± 1.3%, χ² = 9.01, p = 0.003). Children from households of lower SES had higher odds of being overweight/obese; lower SES was defined by lower paternal education (adjusted odds ratio, 1.18; 95% confidence interval, 1.08 to 1.30) and lower area‐level SES (adjusted odds ratio, 1.13; 95% confidence interval, 1.02 to 1.25), adjusted for age, gender, height, and clustering by school. Discussion: The prevalences of overweight and obesity are increasing in Australian children by about one percentage point per year. This equates to ～40,000 more overweight children each year, placing Australian children among those at highest risk around the world. In addition, girls are more likely to be overweight, and there is a general trend for children of lower SES to be at even greater risk of overweight and obesity.     

Total and Regional Fat and Serum Cardiovascular Disease Risk Factors in Lean and Obese Children and Adolescents

Objective: This study was conducted to evaluate the association of total and central adiposity with serum cardiovascular disease (CVD) risk factors in lean and obese Portuguese children and adolescents. Research Methods and Procedures: A total of 87 girls (13.2 ± 1.6 years old, 29.9 ± 6.4% body fat [mean ± SD]) and 72 boys (13.2 ± 1.6 years old, 20.8 ± 9.9% body fat) volunteered for the study. Whole‐body composition and fat distribution, from DXA and anthropometry, and serum lipids, lipoproteins, and apolipoproteins were evaluated. Results: The sum of three trunk skinfolds (STS) was highly correlated with total trunk fat mass measured by DXA (p < 0.001). Body mass index, DXA‐measured percentage of body fat, trunk fat mass, STS, and the waist‐to‐height ratio were generally found to be associated with triacylglycerol, the ratio of total cholesterol (TC) to high density lipoprotein‐cholesterol (HDL‐C), low density lipoprotein‐cholesterol (LDL‐C), and apolipoprotein B levels, (significant age‐adjusted r between 0.16 and 0.27, p < 0.05). Body mass index, STS, and the waist circumference were also associated with HDL‐C (p < 0.05), whereas no body composition variable significantly correlated with TC or apolipoproteins A‐I. The STS was significantly correlated with HDL‐C (p < 0.01), TC/HDL‐C (p < 0.05), and apolipoproteins A‐I (p < 0.05) independently of whole‐body fatness. Obese subjects (n = 73) had higher TC, LDL‐C, TC/HDL‐C, and apolipoprotein B than did non‐obese subjects (n = 86), and significant associations between central adiposity and some lipid variables (triacylglycerol and HDL‐C) were found in obese children and adolescents that were not present in leaner individuals. Discussion: DXA‐ and anthropometry‐based whole‐body and central fat measures are associated with serum CVD risk factors in Portuguese boys and girls. Obese children and adolescents have a poorer lipid profile than do their leaner counterparts. Trunk skinfolds, which are easy to obtain even in large samples, predict CVD risk factors to the same extent as DXA‐based variables, in some cases, independently of total fatness.     

Lower Serum Adiponectin Levels in African‐American Boys

Objective: To examine adiponectin, an adipocyte‐secreted hormone with anti‐inflammatory and insulin‐sensitizing effects, in relation to race or gender in younger subjects. Research Methods and Procedures: The relationship of adiponectin, quantitated by radioimmunoassay, to anthropometric and metabolic factors (fasting insulin, glucose, and leptin) and reproductive hormones was examined in 46 healthy African Americans (25 girls/21 boys) and 40 whites (20 girls/20 boys) ranging in age from 12 to 21 years. Results: There was no statistical difference in BMI or in BMI percentile among the four groups. Sums of skinfolds, but not skinfold percentile, were significantly lower in boys than girls (p = 0.001 and p = 0.896, respectively), whereas there was no difference between racial groups. Leptin was significantly greater in girls (p = 0.0002). There was no difference in fasting serum glucose, insulin, or homeostasis model assessment score among any of the groups. There was a significant negative univariate relationship between serum adiponectin and both BMI and BMI percentile for the entire group (p = 0.006 and p = 0.005). In a multivariate model, BMI percentile (p = 0.005) and the interaction between race and gender (p = 0.026) were significant predictors of serum adiponectin. In this model, African‐American boys had the lowest serum adiponectin level, 37% less than white boys, who had the highest adiponectin levels. Discussion: Serum adiponectin levels are reduced in young obese subjects (African Americans and whites) and are lower in African‐American boys than white boys. A lower adiponectin level in African‐American boys may predispose this group to a greater risk of diabetes and cardiovascular disease.     

Plasma visfatin concentration as a surrogate marker for visceral fat accumulation in obese children

Objective: This study was designed to elucidate whether the plasma visfatin level reflects visceral or subcutaneous fat accumulation and metabolic derangement in obese children. Methods and Procedures: Fifty‐six obese Japanese children, including 37 boys and 19 girls were enrolled in the study. The age of the subjects ranged from 5 to 15 (10.2 ± 0.3; mean ± s.e.m.) years. The age‐matched control group for measuring visfatin consisted of 20 non‐obese children. Visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) areas were measured by computed tomography. The plasma concentrations for visfatin and leptin were assayed by enzyme‐linked immunosorbent assay kits. Results: The plasma visfatin level was higher in the obese (14.7 ± 0.9 ng/ml) than in the control children (8.6 ± 0.6 ng/ml). In a univariate analysis, the visfatin correlated significantly with age, height, body weight, waist circumference, VAT and SAT area, triglyceride (TG), insulin, and the homeostasis model assessment for insulin resistance (HOMA‐R). After being adjusted for age and sex, only the VAT area retained significant partial correlation with visfatin, and in contrast the body weight, BMI–s.d., and SAT area with leptin. The plasma visfatin concentration was not correlated with leptin. The plasma visfatin levels in the control, non‐metabolic syndrome (MS) (n = 49), and MS groups (n = 7) were significantly different from each other. Discussion: These results suggest that plasma visfatin level is a specific marker for visceral fat accumulation in obese children. As a good surrogate marker, plasma visfatin level can predict the VAT area in obese children.     

Relationship between Plasma Adiponectin Levels and Metabolic Risk Profiles in Taiwanese Children

Objective: Adiponectin, a novel adipokine with antiinflammatory and insulin‐sensitizing properties, has an important role in glucose metabolism and is negatively correlated with body fat amount in adults. The purpose of this study was to evaluate the association of plasma adiponectin level with metabolic risk profiles and insulin resistance status among Taiwanese children. Research Methods and Procedures: We enrolled 1248 children (608 boys and 640 girls) to ascertain their demographic, anthropometric, and cardiovascular risk factors distribution in Taipei. We measured plasma insulin, adiponectin, and leptin levels by radioimmunoassay (Linco Research Inc, St. Charles, MO). We calculated an insulin resistance index (IRI) using the Homeostasis Model Assessment model and also calculated an insulin resistance syndrome (IRS) summary score for each individual by adding the quartile ranks from the distribution of systolic blood pressure, serum triglyceride, high‐density lipoprotein‐cholesterol (HDL‐C) (inverse), and insulin levels. Results: In general, the boys had larger BMI, higher systolic blood pressure, serum total cholesterol, and triglyceride, and lower plasma leptin and adiponectin levels than girls. Plasma adiponectin levels were correlated negatively with BMI, leptin, insulin, IRI, and IRS summary score but positively correlated with HDL‐C in both boys and girls. In multivariate regression analyses, adiponectin was negatively associated with insulin (girls only), IRI (girls only), and IRS score, and positively associated with HDL‐C in both genders even after adjusting for age, BMI, plasma leptin level, and other potential confounders. Discussion: These data suggest that plasma adiponectin levels were negatively associated with metabolic risk profiles that may have played a protective role in the development of insulin resistance among Taiwanese school children.     

Visceral Adipose Tissue and Markers of the Insulin Resistance Syndrome in Obese Black and White Teenagers

Objective: To determine the relationships between visceral and general adiposity, cardiovascular fitness, and markers of the insulin resistance syndrome in obese black and white teenagers. Research Methods and Procedures: Cross‐sectional survey of 81 obese 13‐ to 16‐year‐old youths. Visceral adipose tissue was measured with magnetic resonance imaging, and percentage body fat was measured with dual‐energy X‐ray absorptiometry. Cardiovascular fitness was assessed with a submaximal treadmill test. Fasting blood samples were analyzed for lipids/lipoproteins and insulin. Resting blood pressure was obtained using an automated cuff. Results: Visceral adipose tissue was significantly correlated with unfavorable levels of: triacylglycerol (r = 0.27, p < 0.05), total cholesterol (r = 0.27, p < 0.05), high‐density lipoprotein cholesterol (r = ?0.26, p < 0.05), the ratio of total cholesterol/high‐density lipoprotein cholesterol (r = 0.42, p < 0.01), low‐density lipoprotein cholesterol (r = 0.27, p < 0.05), apolipoprotein B (r = 0.38, p < 0.01), and systolic blood pressure (r = 0.30, p < 0.01). Multiple regression analyses revealed that visceral adipose tissue was more powerful than percentage body fat for explaining variance in lipoproteins (e.g., for the ratio of total cholesterol/high‐density lipoprotein cholesterol, r² = 0.13, p < 0.01, and for systolic blood pressure, r² = 0.07, p < 0.05). Ethnicity was the most powerful of the demographic predictors for blood lipids (r² = 0.15 for triacylglycerol with lower levels in blacks; r² = 0.10 for high‐density lipoprotein cholesterol with higher levels in blacks; r² = 0.06 for the ratio of total cholesterol/high‐density lipoprotein cholesterol with lower levels in blacks). Cardiovascular fitness was not retained as a significant predictor of markers of the insulin resistance syndrome. Discussion: Some of the deleterious relationships between visceral adiposity and markers for the insulin resistance syndrome seen in adults were already present in these obese young people.     

Comparison of body fat composition and serum adiponectin levels in diabetic obesity and non-diabetic obesity

Objective: Clinical aspects of diabetes and obesity are somewhat different, even at similar levels of insulin resistance. The purpose of this study was to determine differences in body fat distribution and serum adiponectin concentrations in diabetic and non‐diabetic obese participants. We were also interested in identifying the characteristics of insulin resistance in these two groups, particularly from the standpoint of adiponectin. Research Methods and Procedures: Adiponectin concentrations of 112 type 2 diabetic obese participants and 124 non‐diabetic obese participants were determined. Abdominal adipose tissue areas and midthigh skeletal muscle areas were measured by computed tomography. A homeostasis model assessment of the insulin resistance score was calculated to assess insulin sensitivity. The relationships among serum adiponectin, body fat distribution, and clinical characteristics were also analyzed. Results: Both abdominal subcutaneous and visceral fat areas were higher in the non‐diabetic obese group, whereas midthigh low‐density muscle area was higher in the diabetic obese group. The homeostasis model assessment of the insulin resistance score was similar between groups, whereas serum adiponectin was lower in the diabetic obese group. Abdominal visceral fat (β = ?0.381, p = 0.012) was a more important predictor of adiponectin concentration than low‐density muscle (β = ?0.218, p = 0.026) in cases of non‐diabetic obesity, whereas low‐density muscle (β = ?0.413, p = 0.013) was a better predictor of adiponectin level than abdominal visceral fat (β = ? 0.228, p = 0.044) in diabetic obese patients. Discussion: Therefore, factors involved in pathophysiology, including different serum adiponectin levels and body fat distributions, are believed to be responsible for differences in clinical characteristics, even at similar levels of insulin resistance in both diseases.     

Plasma Adiponectin Levels and Metabolic Factors in Nondiabetic Adolescents

Objectives: The relationship of plasma adiponectin levels with various anthropometric and metabolic factors has been surveyed extensively in adults. However, how plasma adiponectin levels are related to various anthropometric indices and cardiovascular risk factors in adolescents is not as vigorously studied. In this study, we investigated this among healthy nondiabetic adolescents. Research Methods and Procedures: Two hundred thirty nondiabetic subjects (125 boys and 105 girls, ～10 to 19 years old) were included. The plasma adiponectin, fasting plasma glucose, insulin, lipids and anthropometric indices including body height, weight, waist circumference, and hip circumference were examined. Body fat mass (FM) and percentage were obtained from DXA scan. The homeostasis model assessment was applied to estimate the degree of insulin resistance. Results: The plasma adiponectin levels were significantly higher in girls (30.79 ± 14.48 μg/mL) than boys (22.87 ± 11.41 μg/mL). The plasma adiponectin levels were negatively related to BMI, FM, FM percentage, waist circumference, waist‐to‐hip ratio, insulin resistance, plasma insulin, triglycerides, and uric acid levels, but positively with high‐density lipoprotein cholesterol (HDL‐C) with the adjustment for age and gender. Using different multivariate linear regression models, only age and HDL‐C were consistently related to the plasma adiponectin levels after adjustment for the other variables. Discussion: The relationship between plasma adiponectin and various anthropometric indices and metabolic factors, especially HDL‐C, previously reported in adults was present in the healthy nondiabetic adolescents. Whether variation of plasma adiponectin levels in healthy nondiabetic adolescents may influence their future coronary artery disease risk warrants further investigation.     

High‐density Lipoprotein Apolipoprotein A‐I Kinetics in Obesity

Objective: Low plasma concentrations of high‐density lipoprotein (HDL)‐cholesterol and apolipoprotein A‐I (apoA‐I) are independent predictors of coronary artery disease and are often associated with obesity and the metabolic syndrome. However, the underlying kinetic determinants of HDL metabolism are not well understood. Research Methods and Procedures: We pooled data from 13 stable isotope studies to investigate the kinetic determinants of apoA‐I concentrations in lean and overweight—obese individuals. We also examined the associations of HDL kinetics with age, sex, BMI, fasting plasma glucose, fasting insulin, Homeostasis Model Assessment score, and concentrations of apoA‐I, triglycerides, HDL‐cholesterol and low‐density lipoprotein‐cholesterol. Results: Compared with lean individuals, overweight—obese individuals had significantly higher HDL apoA‐I fractional catabolic rate (0.21 ± 0.01 vs. 0.33 ± 0.01 pools/d; p < 0.001) and production rate (PR; 11.3 ± 4.4 vs. 15.8 ± 2.77 mg/kg per day; p = 0.001). In the lean group, HDL apoA‐I PR was significantly associated with apoA‐I concentration (r = 0.455, p = 0.004), whereas in the overweight—obese group, both HDL apoA‐I fractional catabolic rate (r = ?0.396, p = 0.050) and HDL apoA‐I PR (r = 0.399, p = 0.048) were significantly associated with apoA‐I concentration. After adjustment for fasting insulin or Homeostasis Model Assessment score, HDL apoA‐I PR was an independent predictor of apoA‐I concentration. Discussion: In overweight—obese subjects, hypercatabolism of apoA‐I is paralleled by an increased production of apoA‐I, with HDL apoA‐I PR being the stronger determinant of apoA‐I concentration. This could have therapeutic implications for the management of dyslipidemia in individuals with low plasma HDL‐cholesterol.     

Fasting Plasma Insulin Modulates Lipid Levels and Particle Sizes in 2‐ to 3‐Year‐Old Children

Objective: Obesity and hyperinsulinemia are associated with dyslipidemia in adults and older children, but little is known about these relationships in very young children. We examined the relation of fasting insulin to lipid levels and lipid particle size in young healthy children. Research Methods and Procedures: Analyses were performed on data from 491 healthy 2‐ and 3‐year old Hispanic children enrolled in a dietary study conducted in New York City, 1992–1995. Obesity measures included BMI, ponderal index, skinfold thickness, and waist circumference. Low‐density lipoprotein (LDL)‐ and high‐density lipoprotein (HDL)‐cholesterol particle size were measured by nuclear magnetic resonance. Results: Fasting insulin level was positively correlated with triglyceride levels (r = 0.24 for boys and r = 0.23 for girls; p < 0.001 for both) and inversely correlated with HDL‐cholesterol level in boys (r = ?0.20; p < 0.01). Higher fasting insulin level was also correlated with smaller mean HDL particle size in both boys (r = ?0.21; p < 0.001) and girls (r = ?0.14; p < 0.05) and smaller mean LDL particle size in boys (r = ?0.13; p < 0.05). The associations of fasting insulin level with triglyceride and HDL‐cholesterol levels and HDL and LDL particle size remained significant after multivariate regression adjustment for age, sex, and BMI or ponderal index. Discussion: Fasting insulin level is associated with relative dyslipidemia in healthy 2‐ and 3‐year‐old Hispanic children.     

Gender specific effect of LIPC C‐514T polymorphism on obesity and relationship with plasma lipid levels in Chinese children

Hepatic lipase (LIPC) is a key rate‐limiting enzyme in lipoprotein catabolism pathways involved in the development of obesity. The C‐514T polymorphism in the promoter region is associated with decreased LIPC activity. We performed a case‐controlled study (850 obese children and 2119 controls) and evaluated the association between LIPC C‐514T polymorphism, obesity and plasma lipid profile in Chinese children and adolescents. Additionally, we conducted a meta‐analysis of all results from published studies as well as our own data. A significant association between the polymorphism and obesity is observed in boys (P = 0.042), but not in girls. And we observed a significant relationship of the polymorphism with total cholesterol (TC) and high density lipoprotein cholesterol (HDL‐C) independent of obesity in boys. The T allele carriers have higher levels of low density lipoprotein cholesterol (LDL‐C) in obese boys, and triglyceride (TG), TC and LDL‐C in non‐obese girls (all P < 0.05). In the meta‐analysis, under dominant model the T allele increased body mass index (BMI) level in boys, while it decreased BMI in girls, and increased the levels of TC both in the overall and subgroups, TG and HDL‐C in the overall and boys, and LDL‐C in the overall (all P < 0.05). Our results suggest that the T allele might carry an increased risk of obesity in Chinese boys. The meta‐analysis suggests that T allele acts as a risk allele for higher BMI levels in male childhood, while it is a protective allele in female childhood. And the polymorphism is associated with the levels of plasma lipids, which may be modulated by obesity and gender.     

Lipid and insulin levels in obese children: changes with age and puberty

Objective: The goal was to describe the lipid profile and insulin changes seen in obese children and adolescents at different stages of puberty. Research Methods and Procedures: A cross‐sectional study was conducted by chart review of 181 obese (BMI > 95th) children and adolescents 5 to 17 years of age, who were referred to the Center for Atherosclerosis Prevention for cardiovascular risk reduction from January 2003 through December 2003. Results: Eighty (44.2%) subjects were <12 years of age, and 101 (55.8%) were ≥12 years. Severity of obesity as expressed by BMI standard deviation score did not differ between these age groups. A significant difference with lower serum levels of total cholesterol, non‐high‐density lipoprotein cholesterol, low‐density lipoprotein cholesterol, and high‐density lipoprotein cholesterol was seen with older age and with advancing sexual maturity rating. Triglycerides, very‐low‐density lipoprotein cholesterol, and lipoprotein(a) levels remained elevated across age and pubertal stages. Insulin levels and insulin resistance as expressed by homeostasis model assessment were significantly higher with older age. Similar trends were observed both in obese boys and obese girls during puberty. Discussion: The most striking findings of this study are that in the 5‐ to 17‐year‐old obese population, the combination of elevated triglycerides and very‐low‐density lipoprotein cholesterol and low high‐density lipoprotein cholesterol levels place them at greater cardiovascular risk than their non‐obese peers, even when the changing patterns of lipids and lipoproteins seen during pubertal maturation are accounted for.     

Frequency of non-alcoholic fatty liver disease in overweight/obese children and adults: Clinical,sonographic picture and biochemical assessment

Non-alcoholic fatty liver disease (NAFLD) is a condition defined by significant lipid accumulation (5–10%) in hepatic tissue in the absence of significant chronic alcohol consumption. We aim to detect frequency of fatty liver among overweight/obese adults and children and associated clinical; anthropological measures; biochemical; genetic and imaging studies. Eighty three consecutive adults and 72 children included in the study. All patients underwent clinical measurements of height, body weight, body mass index (BMI), waist and hip circumference. Biochemical investigations were done to all subjects including liver function tests; lipid profile; fasting blood glucose; insulin resistance (IR); high sensitivity C reactive protein (hs-CRP); adiponectin and genotyping of adiponectin genes. Abdominal ultrasonography was done to search for fatty liver; to measure subcutaneous fat thickness (SFT) and visceral fat thickness (VFT). Fatty liver was detected in 47 (65.3%) children and in 52 (62.7%) adults. Correlation analysis in both groups revealed that enlarged liver was highly positively correlated to age; BMI, systolic blood pressure (SBP), diastolic blood pressure (DBP); waist circumference; hip circumference, subcutaneous fat thickness (SFT) and Visceral fat thickness (VFT), alanine aminotransferase (ALT), aspartate aminotransferase/alanine aminotransferase (AST/ALT). In addition in adults to fasting blood glucose, cholesterol, triglycerides (TG), low density lipoprotein (LDL), IR and hs-CRP. Homozygous T adiponectin genotype at position +276 was significantly increased among children with enlarged liver size and hs-CRP. NAFLD affects a substantial portion of adults and children; it is associated with the metabolic syndrome.     

Subdivision of the Subcutaneous Adipose Tissue Compartment and Lipid‐Lipoprotein Levels in Women

Objective: The aim of this study was to compare the relative importance of computed tomography‐measured abdominal fat compartment areas, including adipose tissue located posterior to the subcutaneous Fascia, in predicting plasma lipid‐lipoprotein alterations. Research Methods and Procedures: Areas of visceral as well as subcutaneous deep and superficial abdominal adipose tissue were measured by computed tomography in a sample of 66 healthy women, ages 37 to 60 years, for whom a detailed lipid‐lipoprotein profile was available. Results: Strong significant associations were observed between visceral adipose tissue area and most variables of the lipid‐lipoprotein profile (r = ?0.25, p < 0.05 to 0.62, p < 0.0001). Measures of hepatic lipoprotein synthesis such as very‐low‐density lipoprotein‐triglyceride and cholesterol content as well as total and very‐low‐density lipoprotein‐apolipoprotein B levels were also strongly associated with visceral adipose tissue area (r = 0.57, 0.57, 0.61, and 0.62, respectively, p < 0.0001). Significant associations were found between these variables and the deep subcutaneous adipose tissue area or DXA‐measured total body fat mass. However, the correlation coefficients were of lower magnitude compared to those with visceral adipose tissue area. Multivariate regression analyses demonstrated that visceral adipose tissue area was the strongest predictor of lipid‐lipoprotein profile variables (7% to 48% explained variance, 0.02 ≥ p ≤ 0.0001). Discussion: Although previous studies have generated controversial data as to which abdominal adipose tissue compartment was more closely associated with insulin resistance, our results suggest that visceral adipose tissue area is a stronger correlate of other obesity‐related outcomes such as lipid‐lipoprotein alterations.