Background: The importance of small dense low-density lipoprotein (sdLDL) cholesterol in coronary heart disease has been demonstrated in many studies. Body fat accumulation, especially abdominal ...adiposity, is one of the important factors modifying the expression of sdLDL in adults. Objective: To determine the prevalence of sdLDL in obese children, and to investigate its relationship with anthropometric and metabolic variables. Subjects: A total of 30 obese children (22 males, 8 females) aged 12.6+/-0.6 years (mean+/-s.e.), who presented to our outpatient clinic with obesity. Methods: LDL peak particle diameter was determined using gel electrophoresis. LDL subclasses were classified into sdLDL (pattern B; diameter<25.5 nm) and non-sdLDL (pattern A; diameter>or=25.5 nm). Anthropometric and metabolic variables were also determined to identify factors modifying LDL particle size. Results: sdLDL was detected in 11 children (40.0%). In children with sdLDL, waist/height ratio was significantly higher (P=0.0466), and they had significantly higher triglyceride (TG) (P=0.0035) and lower high-density lipoprotein cholesterol (HDLC) levels (P=0.036). Peak LDL diameter as a continuous variable was significantly correlated with HDLC and TG levels. In multiple regression analysis, body mass index and waist/height ratio were significant determinants of the peak LDL diameter variability. Conclusions: We found a high prevalence of sdLDL in obese children, and a relationship of peak LDL diameter with abdominal fat accumulation, HDLC and TG levels. The presence of sdLDL might be an important risk factor for the metabolic syndrome.
BACKGROUND:Palmitoleic acid (16:1n-7) is a product of endogenous lipogenesis. In human obesity, 16:1n-7 is reported to correlate with indexes of adiposity and insulin concentrations. OBJECTIVE:We ...investigated the relation between adiposity, especially in the abdominal region, and plasma monounsaturated fatty acid (MUFA) profiles in obese children. DESIGN:A case-control study was performed. The study subjects were 59 obese children (Formula: see text ± SD age: 11.8 ± 3.8 y) and 53 age- and sex-matched healthy, nonobese children (aged 12.5 ± 0.5 y). The study's variables included anthropometric measurements, serum lipids, leptin, and fatty acid composition in plasma. RESULTS:MUFA profiles of obese subjects showed a significantly higher content of 16:1n-7, 18:1n-9, and 20:1n-9 and significantly higher stearoyl-CoA desaturase (SCD) activity (ratio of 16:1n-7 to 16:0) than in nonobese controls. In a multiple regression analysis, percentage body fat, waist-to-height ratio, and waist-to-hip ratio (WHR) were significant determinants of 16:1n-7 content. SCD activity had a positive, significant correlation with leptin. However, in a multiple regression analysis that included percentage body fat, WHR, and leptin as independent determinants, WHR was the only determinant of SCD activity. CONCLUSIONS:Plasma 16:1n-7 content has a significant relation with abdominal adiposity in obese children. This change in the MUFA profile may be caused by activation of SCD that is not sufficiently suppressed by leptin. Endogenous lipogenesis may be an important factor in the pathogenesis of obesity in children.
Background
: In order to know whether the changes in indexes of overweight, body mass index (BMI; kg/m2) and percentage of overweight (POW) (%), really represent the tendency toward obesity, we ...examined longitudinal individual changes in these indexes, and the change in body composition in boys during early pubertal period.
Methods
: The subjects were 50 school boys who lived in Shizuoka, Japan. Standing height and weight were measured, and BMI and POW were obtained. Body fat percentage (BF%), fat mass (FM) and lean body mass (LBM) were estimated by bioelectrical impedance method. The influence of predictive variables (LBM, FM) on the changes in BMI and POW was investigated by multiple regression analysis. We examined the 3‐year changes in BMI, POW and predictive variables in each individual, from 9 to 12 years of age.
Results
: The mean change of BMI was 1.7 ± 0.3 (mean ± SEM) kg/m2 and that of POW was 2.2 ± 1.9%. The influence of predictive variables on the changes in BMI and POW was determined. The variance of the change in POW could be explained by that in FM (r2 = 0.737, P < 0.0001), while the change in BMI was influenced by both LBM and FM (r2 = 0.891, P < 0.0001).
Conclusions
: Based on the definition of obesity, POW is the better index of body fatness to assess its individual change for boys during early pubertal period, because the index independent from the change in LBM is supposed to be the appropriate index for obesity in practical use.
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