New criteria of normal serum lipid levels in Japanese children: the nationwide study

Prevalence of obesity, hyperlipemia and insulin resistance in children with suprasellar brain tumors

Weight gain is a common sequela of suprasellar tumors, referred to as hypothalamic obesity. We undertook an evaluation of obesity and metabolic aberrations among patients treated at our institute. During the 12 mo from Apr. 2005, 23 patients (10 males and 13 females) with remitted suprasellar tumors attended our clinic: 10 patients with craniopharyngioma, 7 with germinoma, 4 with optic nerve glioma and others. Of these, 12 patients (52%) were found to have obesity on the basis of percent overweight and/or percent body fat. Elevated cholesterol and/or triglyceride (TG) was found in 9 patients (39%), and insulin resistance was suspected in 7 patients (30%). Three patients exhibited strikingly elevated postprandial TG levels. All 6 patients with the growth without GH phenomenon had at least one metabolic aberration. In conclusion, the prevalence of hypothalamic obesity was nearly half in our series, and hyperlipemia and insulin resistance were also frequently found. The increased risk for metabolic aberration in growth without GH patients was suggested.

Relationship Between Lipid Abnormalities and Insulin Resistance in Japanese School Children

Objective— Dyslipidemia and insulin resistance (IR) are risk factors for coronary heart disease (CHD) in adults. To help prevent the development of CHD, it may be useful to understand the relationship between lipid abnormalities and IR during childhood.

Methods and Results— IR was assessed by the homeostasis model approximation index. We studied 1175 Japanese school children (642 boys and 533 girls), aged between 7 and 12 years. Obesity was defined by the body mass index standard deviation score (BMISD) (obese: BMISD ≥2.0). BMISD was most significantly associated with IR in nonobese children ( P =0.000). Associations of IR with lipid-related parameters were affected by BMISD. After being corrected by BMISD, in nonobese children, log triglycerides (TG), apoB and low-density lipoprotein (LDL) size in boys and log TG, LDL size, and high-density lipoprotein (HDL) cholesterol in girls were still significantly associated with IR ( P =0.000 to 0.017). In obese children, all parameters except for LDL cholesterol in boys and LDL size in girls were significantly associated with IR ( P =0.000 to 0.030). Multiple regression analysis showed that log TG and LDL size in nonobese children, log TG in obese boys and LDL size in obese girls were independently associated with IR. Children with IIb and IV hyperlipidemia had significantly higher IR than those with normolipidemia and IIa, even after correcting for BMISD and age.

Conclusion— Our results suggest that in addition to controlling body weight, it may be important for school children to characterize lipid phenotypes to prevent progression to CHD and/or type 2 diabetes and to identify subjects who are at high risk for these disorders.

Relationship between serum adiponectin level and lipid composition in each lipoprotein fraction in adolescent children

The association of lipid composition in each lipoprotein fraction with adiponectin level in relation to body fatness was investigated. The subjects were 283 children (144 boys and 139 girls) aged 11.6 years (S.D. 1.5). Cholesterol (C) and triglyceride (TG) levels in each lipoprotein fraction were measured by a combination of agarose gel electrophoresis and differential staining. Adiponectin level was not significantly different between girls and boys. In simple regression analyses, an association of adiponectin level with lipoprotein lipid profile was shown only in girls, and not in boys at all. In girls, very low-density lipoprotein (VLDL)-C, low-density lipoprotein (LDL)-C, VLDL-TG and LDL-TG were negatively correlated with adiponectin level, and high-density lipoprotein (HDL)-C and HDL-C/TG ratio were positively correlated. Multiple regression analyses including adiponectin level and body mass index (BMI) as predictors for the lipoprotein lipid profile demonstrated that adiponectin level was a significant independent predictor of VLDL-TG, LDL-C, LDL-TG, HDL-C and HDL-C/TG ratio. In conclusion, adiponectin level correlates with lipoprotein lipid profile independent of body fatness in adolescent girls.

LDL particle size, fat distribution and insulin resistance in obese children

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.

Determination of Lipid Composition of Plasma Lipoproteins in Children with a Rapid Agarose Gel Electrophoresis Method

The agarose gel electrophoresis and differential staining system is an easy and quick method for analyzing the serum lipid composition of each lipoprotein fraction. It has been reported in adults that measured values obtained by this method strongly correlated with those obtained by ultracentrifugation. The aim of this study was to examine the clinical application of this method for children, in comparison with the ultracentrifugation method. The subjects were sixteen hyperlipidemic and twenty-five normolipidemic children, aged from two to eighteen years old. Cholesterol (C) and triglyceride (TG) levels were determined in serum very low density lipoprotein (VLDL), low density lipoprotein (LDL), and high density lipoprotein (HDL) fractions by both methods. Correlation coefficients between the two methods for cholesterol levels were 0.937 (HDL), 0.983 (LDL) and 0.837 (VLDL), and for triglyceride levels were 0.735 (HDL), 0.621 (LDL) and 0.964 (VLDL). We confirmed the clinical application of this method to evaluate the lipoprotein lipid profile in children as well as in adults.

Serum lipid levels and factors affecting atherogenic index in Japanese children

An evaluation was made of the serum lipid levels and factors relating to atherogenicity in schoolchildren in Akita, Japan, in order to determine actual conditions and promote awareness of health. The subjects were 2878 boys and 2729 girls aged 9, 12 and 15 years, who lived in cities, towns and villages in the Akita prefecture. Physical and lifestyle data including serum lipids were collected from the subjects in their schools under the direction of the prefectural board of education. Total cholesterol levels were found to be nearly equal to those currently representative for Japanese children, ethnically situated between blacks and whites in the United States of America. Atherogenic indices (AIs) were lower than those in all other countries owing to the elevated high-density lipoprotein (HDL) cholesterol levels observed in this study. According to data obtained from the questionnaires that were part of the study, regularly taking breakfast and exercising in sports clubs seems connected to maintaining lower atherogenicity in childhood.

Association of low-density lipoprotein particle size distribution and cardiovascular risk factors in children

AIM

The objective of this study was to investigate whether the presence of small, dense lipoproteins, which are thought to be related to the metabolic syndrome caused by insulin resistance, can be predicted by routine serum lipid profiling.

METHODS

The relationship between low-density lipoprotein (LDL) particle size and serum lipid levels was analysed in 284 school children (148 boys and 136 girls), aged 7 to 13 y old. LDL particle size was determined by gradient gel electrophoresis.

RESULTS

The LDL particle diameter was significantly correlated with the serum levels of high-density lipoprotein cholesterol (HDL-C) (r = - 0.437, p < 0.001) and triglycerides (TG) (r = -0.432, p < 0.001), and with the atherogenic index (AI) [total cholesterol/ HDL-C] (r = -0.450, p < 0.001), while only weak correlations were observed with the serum levels of total cholesterol, apolipoprotein Al and apolipoprotein B. No significant relationship was observed between LDL particle diameter and the serum LDL-C level.

CONCLUSION

The presence of small, dense LDL as a metabolic marker of lifestyle-related diseases in children seems to be reflected by a serum lipid profile characterized by an elevation in TG, a reduction in HDL-C, and a raised AI.

Serum lipid profile in obese children in China

BACKGROUND

The aim of the present study was to examine the serum lipid profile in obese Chinese children, their serum lipid and apolipoprotein A-I (apoA-I) and B (apoB) levels were examined.

METHODS

The subjects were 153 patients (109 male and 44 female) aged 4-16 years with obesity, who attended the outpatient clinic of Beijing Children's Hospital. Percentage bodyweight (%BW) ([(bodyweight - standard weight)/standard weight]x 100) were obtained. Skinfold thickness and hip and waist circumference were measured. Percentage body fat (%BF) was estimated by bioelectrical impedance analyzer. Serum total cholesterol (TC), high density lipoprotein cholesterol (HDLC), triglyceride (TG), apoA-I and apoB levels were also measured.

RESULTS

TC showed an acceptable level in 86.8% of obese children. The prevalence of high TC levels (3.3%) or high LDLC levels (6.0%) was rather low. The HDLC level was reduced in 31.3% of obese children. Anthropometric variables had no linear relationship to TC, HDLC, TG, LDLC, apoA-I or apoB, but in the older age group (over 10 years old) %BW and %BF showed a weak correlation with HDLC (r = -0.202, r = -0.211, respectively).

CONCLUSION

In obese Chinese children, HDLC as well as TC levels should be examined in order to assess coronary risk.

Prevention of mildly overweight children from development of more overweight condition

BACKGROUND

A follow-up study has reported that not only highly obese but also mildly obese children are becoming heavier during the elementary school children. Then we determined the effect of programs for the screening and treatment of overweight elementary school children whether the programs prevented mildly overweight children from development of more overweight condition.

METHODS

Subjects were 40 overweight children who participated in both screening and treatment programs. As controls, only 240 children who participated in the screening program were used. The mean observation periods of the subjects and controls were 14 and 12 months, respectively.

RESULTS

In both groups, older and heavier children significantly decreased their indices of overweight (percent relative body weight; %RBW), indicating that mildly obese children worsened their %RBW. However, the incidence of children who worsened their %RBW was significantly lower in the subjects (5 of 40) than in the controls (133 of 240) (P < 0.0001). Finally, the subjects significantly reduced their mean %RBW (P < 0.0001) and the controls significantly worsened it (P = 0.0093).

CONCLUSION

The treatment program was found important because it prevents mildly overweight children who may worsen their overweight indices without the program from developing more overweight condition.

The Levels of Serum Low-Density Lipoprotein Cholesterol Using Direct Measurement in Healthy Japanese School Children

This study aimed to investigate the levels of serum low-density lipoprotein cholesterol (LDLC) using direct measurement in healthy Japanese school children. The subjects were 621 children (325 boys and 296 girls) aged 9 to 10 in the 4th grade, and 688 children (334 boys and 354 girls) aged 12 to 13 in the 7th grade. The levels of serum LDLC and high-density lipoprotein cholesterol were measured by direct determination (Cholestest LDL and Cholestest NHDL; Daiichi Pure Chemicals Co., Ltd., Tokyo, Japan). In boys in the 4th grade, the mean, the 75th, the 90th and the 95th percentiles of LDLC levels (mg/dl) were 91.6, 104, 124 and 134, respectively. In girls in the 4th grade, they were 92.8, 108, 122 and 130. In boys in the 7th grade, they were 83.4, 96, 113 and 123. In girls in the 7th grade, they were 93.0, 106, 126 and 137. Serum LDLC levels in boys in the 7th grade were lower than those of other groups. The direct measurement of serum LDLC level is useful for evaluation of dyslipidemia in healthy school children, because the method is applicable to non-fasting serum.

Criteria for medical intervention in obese children: a new definition of 'obesity disease' in Japanese children

The Committee of the Japan Society for the Study of Obesity reported the new criteria for 'obesity disease' for Japanese adults in 2000. We defined the criteria for the diagnosis of obesity in children with medical problems, corresponding to the 'obesity disease' criteria in adults. Obesity in childhood was defined as follows: percentage of overweight (POW) and body fat exceeded the criteria. 'Obesity disease in childhood' was defined as obesity associated with health or medical problems, and with indications for medical intervention. Medical problems with indications for immediate intervention were grouped as A problems, which consisted of (i). hypertension; (ii). sleep apnea or hypoventilation; (iii). Type 2 diabetes mellitus or impaired glucose tolerance; and (iv). increased waist circumference or accumulation of visceral adipose tissue. Metabolic derangements or equivalent associated with obesity were grouped as B problems: (i). liver dysfunction; (ii). hyperinsulinemia; (iii). hypercholesterolemia; (iv). hypertriglyceridemia; (v). low serum high-density lipoprotein cholesterol; (vi). acanthosis nigricans, and (vii). hyperuricemia. Obese children over 5 years of age with following conditions were diagnosed as 'obesity disease in childhood': (i). any 'A problem', (ii) POW >or= 50% and any 'B problem', or (3) POW < 50% and more than one 'B problem' or equivalent. We decided to take physicosocial problems related to obesity into consideration as the criteria. The resultant criteria are proposed by the Committee for Research of Appropriate Body Build in Children*.