Birthweight and stature, body mass index and fat distribution of 14-year-old Polish adolescents

OBJECTIVES: The relationships between intra-uterine growth retardation and stature, relative weight and fat distribution at adolescence have not been comprehensively established. The aim of this report is to assess the effect of low birthweight on stature, relative weight and fat distribution in 14-year-old boys and girls from Wroclaw, Poland. METHODOLOGY: Cross-sectional measurements of 1197 boys and 819 post-menarcheal girls aged 13.50-14.49 years were performed during medical examinations in 1997. Stature, body mass index (BMI; kg/m2), waist-to-hip ratio (WHR) and waist-to-thigh ratio (WTR) were used in the present study. A cut-off value of the 10th percentile of birthweight for particular gestational weeks was used in order to define subjects born small for gestational age (SGA) or appropriate for gestational age (AGA). Two-way ANOVA was used to evaluate the effect of birthweight on anthropometric variables of 14-year-old adolescents, allowing for socioeconomic status (determined by the level of the mother's education). RESULTS: Birthweight affected stature in boys and girls (P < 0.001), BMI in boys (P < 0.05) and WHR and WTR in girls (P < 0.001 and P < 0.05, respectively). At the age of 14 years, both SGA boys and girls were shorter than their AGA peers. The SGA boys had lower BMI, whereas SGA girls accumulated more centralized fat compared with their AGA counterparts. CONCLUSION: Fetal growth retardation has a long-lasting adverse effect on later physical growth. Polish SGA children do not catch up with their peers in terms of stature by adolescence. Moreover, central fat distribution, as observed among SGA girls, constitutes a significant risk for several adult degenerative diseases.     

Sex‐specific association between leptin receptor polymorphisms and leptin levels and BMI in healthy adolescents*

Aim: To examine the relationship of three common polymorphisms in the leptin receptor (LEPR) gene, implicated in the regulation of body weight, with leptin levels and obesity‐related phenotypes in a population‐based sample of healthy pubertal children in Spain. Methods: The study included 806 boys and girls aged 12–16 whose anthropometrical data and body composition were recorded. Serum leptin levels were determined by ELISA. The LEPR Q223R, K109R and K656N polymorphisms were determined by TaqMan® allelic discrimination assays. Results: When analysing the Q223R polymorphism, we observed that female carriers of the RR genotype had significantly higher plasma leptin levels (18.2 vs. 15.1 ng/mL p = 0.016) and significantly higher mean BMI values (22.5 vs. 21.3 Kg/m² p = 0.032) than QR carriers. Furthermore, the frequency of the RR genotype in overweight‐obese girls was significantly higher than that found in normal‐weight girls. No significant differences were observed in boys. Neither boys nor girls showed significant differences when comparing leptin levels, anthropometric variables or body composition by K109R or K656N genotype. Conclusion: The fact, that the Q223R polymorphism in the LEPR gene is significantly associated with leptin levels and BMI only in girls, suggests a sex‐specific influence of this polymorphism on these variables.     

Serum leptin levels during childhood and adolescence: relationship with age, sex, adiposity and puberty

We studied serum leptin levels in 189 healthy children to evaluate related factors during childhood and adolescence. Leptin correlated with body mass index (BMI), triceps skinfold thickness (p<0.001) and body weight (p<0.01). Obese children and girls had higher leptin levels than non-obese children and boys, respectively (p<0.001). In girls, leptin correlated positively with age, skinfold thickness and BMI (p<0.001). In boys, leptin correlated negatively with age (p<0.001) and positively with skinfold thickness (p<0.05). Prepubertal boys had higher leptin levels than prepubertal girls and pubertal boys (p<0.05). Pubertal girls had higher leptin levels than prepubertal girls and pubertal boys (p<0.001). Leptin levels in girls were higher at Tanner stages 4 and 5 than at stage 1 (p<0.001). In conclusion, serum leptin levels are related with adiposity, have obviously age-related gender differences during childhood and adolescence, and may be involved in the maturation of reproductive capacity.     

Study of top ballet school students revealed large deficiencies in their body weight and body fat

Aim

This study assessed the nutritional status and physical activity levels of 150 female students aged 10–18 from three top Polish ballet schools, where the most promising dancers go on to pursue professional ballet careers.

Methods

We analysed the girls’ body composition, physical activity level (PAL) and PAL coefficient. The ballet students also completed a questionnaire.

Results

The results revealed large deficiencies in the body weight and body fat of the young ballerinas. The mean body mass index (BMI) for the group was 16.8 kg/m². Polish centile charts showed that 18% of the girls had BMIs below the norm and 54% had a lower than average body fat content, with a mean of 15.6%. The body fat content was lowest (13.8%) in the 13‐ to 15‐year age group. On average, girls aged 10–12 had 15.7% body fat, while girls aged 16–18 had 18.4%. The mean values for the anthropometric measurements were higher in older girls. The majority (72%) of the respondents reported high physical activity levels, defined as more than 15 hours of exercise per week.

Conclusion

Special attention should be paid to low BMIs and body fat in young ballet school dancers aged 10–15 years.     

Reduced gains in fat and fat-free mass, and elevated leptin levels in children and adolescents with cystic fibrosis

Aim: Bodyweight is an important prognostic indicator in children with cystic fibrosis (CF), but the relationships between body composition and clinical outcomes are less clear. We have investigated the role of leptin (a potential satiety factor) and changes in body composition, height and weight with respect to age and clinical outcome. Methods: 143 children (77 boys) with CF and a median age (range) of 5.99 (2.27-17.98) y were followed with annual measurements of height, weight, skinfolds, forced expiratory volume (FEV ₁ ), Shwachman score assessment and fasting blood sample. Our control group comprised 40 children (20 boys, 20 girls) aged 8.6-10.2 y at recruitment who were participating in a longitudinal study of growth and puberty. Results: SD scores for height, weight and BMI decreased with age; fat and fat-free mass was lower in both sexes compared to controls. Shwachman score decreased with age in both sexes and was related to fat-free mass in girls, and to both fat-free and fat mass in boys. FEV ₁ decreased with age only in boys and was related to fat-free mass. Leptin levels by age and by fat mass were higher in CF children compared to controls.

Conclusion: Despite improvements in management, contemporary children with CF still gain less body fat and fat-free mass and are shorter than controls. The higher leptin levels we observed may be due to stimulatory effects of inflammatory cytokines and we postulate that they may contribute to the anorexia, poor weight gain and growth of these children.     

经济不发达地区3～9岁儿童血清瘦素水平的变化

目的：了解经济不发达地区3～9岁儿童在营养状况相对较差时血清瘦素的水平及与相关生长发育指标的关系。方法：根据年龄和性别将研究对象分为<6岁女孩组(F36组)、<6岁男孩组(M36)、≥6岁女孩组(F69组)和≥6岁男孩组(M69组)共4组,调查其年龄、体重、身高并计算体重指数(BMI)、体脂百分量(BF%),使用双抗体夹心ELISA法检测瘦素浓度,比较各组间瘦素浓度的差异,同时在各组分析瘦素与各指标间的相关性。结果：①瘦素浓度在同性别比较中,差异无显著性(P>0.05),在同年龄比较中,女孩明显高于男孩(P<0.05);②无论是男孩还是女孩,在3～6岁儿童瘦素与BMI和BF无明显相关(P>0.05),而在6～9岁儿童瘦素浓度与BMI和BF显著相关(P<0.05)。结论：在经济不发达地区3～9岁儿童中瘦素存在性别差异,6～9岁儿童中瘦素与BMI和BF密切相关。     

Leptin profile in neonatal gonadotropin surge and relationship between leptin and body mass index in early infancy

AIM: This study was designed to investigate the longitudinal and dynamic profile of leptin and its relationship with sex hormones including luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol (E2) and testosterone (TTE) in neonatal 'minipuberty'. We also investigated the effects of leptin in the regulation of body weight gain and body mass index (BMI) in the first 3 months of life. METHODS: A longitudinal study was carried out in a cohort of 15 male and 15 female term infants during the first 3 months of life. Blood samples were collected in the morning from the infants on the 3rd, 15th, 30th, and 90th days of life. At each sample collection, anthropometric measurements were recorded. Serum leptin, LH, FSH, E2 (girls only) and TTE (boys only) concentrations were analyzed using standard biochemical methods. Association of leptin with weight gain, BMI, and these hormones during infancy was evaluated. RESULTS: Leptin levels increased significantly between the 3rd and 90th days of life in both boys and girls. BMI of both groups increased significantly from the 3rd to the 90th day. There was no significant difference in the leptin levels and leptin/BMI ratios of the two sexes at different time points. Leptin levels on the 30th and 90th days correlated significantly with BMI in both sexes. LH and FSH levels in both groups were found to be significantly higher on the 15th day of life. No correlation was observed between leptin and LH, FSH, E2 or TTE levels throughout the study. CONCLUSIONS: Leptin levels do not differ between the two sexes during early infancy and possibly there is no role for leptin in the surge of gonadotropins or sex steroids in neonatal minipuberty. The relationship between leptin and BMI could not be seen in the first postnatal days and the transient lack of the regulatory effect of BMI on leptin concentrations might reflect an adaptive resistance in the production of leptin to support catch-up growth after initial physiological weight loss in newborns.     

Leptin, insulin-like growth factor (IGF)-I and IGF binding protein-3 levels in children with constitutional delay of growth

This study was planned in order to investigate the role of insulin-like growth factor-I (IGF-I), IGF binding protein-3 (IGFBP-3) and leptin, the product of the ob gene synthesized by fat tissue cells, in constitutional delay of growth and puberty (CDGP) which is the most frequent cause of short stature in children. This study was conducted on 80 children with CDGP aged 6-15 years, and 60 healthy children served as controls. Serum IGF-I, IGFBP-3, insulin and plasma leptin levels were measured by immunoradiometric assay. Mean IGF-I and leptin levels were significantly lower in the CDGP group compared with the controls, but the mean IGFBP-3 level was not different in the two groups. Mean leptin levels were 3.72 +/- 2.29 in CDGP and 4.68 +/- 3.08 in the control group (p <0.05). There was a statistically significant relationship between leptin levels and height, weight, and body mass index. Leptin levels were also correlated with chronological age, bone age and height age. When evaluated according to pubertal status, a significant difference was found in IGF-I, leptin and IGFBP-3 levels between prepubertal and pubertal groups. Leptin levels were significantly different in the prepubertal CDGP group compared with controls but in the pubertal CDGP group only IGF-I levels were significantly different from controls. As the weight of children with CDGP was lower than in the control group, it is postulated that the reason for short stature and pubertal delay may be this decrease in weight which is also the cause of low levels of leptin and IGF-I.     

Impact of ethnicity upon body composition assessment in Sri Lankan Australian children

OBJECTIVES: Obesity is a disease with excess body fat where health is adversely affected. Therefore it is prudent to make the diagnosis of obesity based on the measure of percentage body fat. Body composition of a group of Australian children of Sri Lankan origin were studied to evaluate the applicability of some bedside techniques in the measurement of percentage body fat. METHODS: Height (H) and weight (W) was measured and BMI (W/H(2)) calculated. Bioelectrical impedance analysis (BIA) was measured using tetra polar technique with an 800 microA current of 50 Hz frequency. Total body water was used as a reference method and was determined by deuterium dilution and fat free mass and hence fat mass (FM) derived using age and gender specific constants. Percentage FM was estimated using four predictive equations, which used BIA and anthropometric measurements. RESULTS: Twenty-seven boys and 15 girls were studied with mean ages being 9.1 years and 9.6 years, respectively. Girls had a significantly higher FM compared to boys. The mean percentage FM of boys (22.9 +/- 8.7%) was higher than the limit for obesity and for girls (29.0 +/- 6.0%) it was just below the cut-off. BMI was comparatively low. All but BIA equation in boys under estimated the percentage FM. The impedance index and weight showed a strong association with total body water (r(2)= 0.96, P < 0.001). Except for BIA in boys all other techniques under diagnosed obesity. CONCLUSIONS: Sri Lankan Australian children appear to have a high percentage of fat with a low BMI and some of the available indirect techniques are not helpful in the assessment of body composition. Therefore ethnic and/or population specific predictive equations have to be developed for the assessment of body composition, especially in a multicultural society using indirect methods such as BIA or anthropometry.     

High-molecular-weight adiponectin and anthropometric variables among elementary schoolchildren: a population-based cross-sectional study in Japan

ABSTRACT: BACKGROUND: Studies about the relationship between high-molecular-weight adiponectin (HMW-adn) and anthropometric variables among population-based elementary schoolchildren have been too limited, especially in Japan, where blood collection is not usually performed in the annual health examination at elementary schools. The objective of the present study was to investigate the relationship between HMW-adn and anthropometric variables (body mass index [BMI], percent body fat [%BF], waist circumference [WC], and waist-to-height ratio [WHtR]) among population-based elementary schoolchildren in Japan. METHODS: Subjects comprised all fourth-grade schoolchildren (9 or 10 years of age) in the town of Ina, Saitama Prefecture, Japan during 2005--2008 (N = 1675). After excluding 21 subjects because of refusal to participate or incomplete data, data from a total of 1654 subjects (846 boys and 808 girls) were analyzed. The height, weight, %BF, and WC of each subject were measured, while blood samples were drawn from the subjects to measure adiponectin levels (HMW-adn and total adiponectin). Childhood obesity was determined according to the age- and sex-specific cut-off points proposed by the International Obesity Task Force. Spearman's correlation coefficients between adiponectin levels and anthropometric variables were calculated for each sex. RESULTS: The anthropometric variables were negatively correlated with HMW-adn in both boys and girls. Correlation coefficients of HMW-adn with anthropometric variables in the obesity group were consistently higher than those in the non-obesity group among both boys and girls. In addition, only WHtR was significantly correlated with HMW-adn regardless of sex and physique (obesity or non-obesity); the correlation coefficient was -0.386 among boys and -0.543 among girls in the obesity group, while it was -0.124 among boys and -0.081 among girls in the non-obesity group. CONCLUSIONS: HMW-adn was negatively correlated with anthropometric variables, while the correlation coefficients of HMW-adn with anthropometric variables in the obesity group were consistently higher than those in the non-obesity group. Moreover, only WHtR was significantly associated with HMW-adn regardless of sex and physique. The results of this study suggested that it is useful to monitor WHtR as a surrogate for HMW-adn among elementary school students, especially obese children.     

Insulin and insulin resistance index are not independent determinants for the variation in leptin in obese children and adolescents

Recent findings have questioned the independent influence of insulin on leptin. We studied whether insulin contributes to leptin in obese children, independent of confounding parameters, such as total adiposity, fasting insulin resistance index, and fat free mass. In 100 obese boys and 103 obese girls, blood levels of leptin, insulin, glucose, and triglycerides were determined. The fasting insulin resistance index (FIRI) was calculated, and body composition was assessed by means of impedance. Leptin and glucose were higher in girls, and all estimates of adiposity were significantly associated with leptin. However, when adjusted for adiposity, the relationship between insulin and leptin, and also between FIRI and leptin, remained significant in boys and girls (p<0.05). Although several regression models were tested, neither insulin nor FIRI were found to contribute significantly and independently to leptin. BMI together with triglycerides and FFM were the main determinants for the variation in leptin in boys (adj. R2=0.46, p<0.0001). In girls, BMI explained a great magnitude of the variation in leptin (adj. R2=0.60, p<0.0001). These findings indicate that in the state of childhood and adolescent obesity, total adiposity but not insulin or insulin resistance index is the main determinant for leptin. In contrast to obese girls, the fat free mass and triglycerides contribute significantly to the variation in leptin in obese boys. The biological significance for these findings should be elucidated in longitudinal studies.     

Leptin is closely related to body fat in prepubertal children aged 8-11 years

BACKGROUND: In adults and obese children, serum leptin concentrations are closely related to body fat. AIM: To investigate whether such a relationship between leptin concentrations and body fat is also evident in children with a relatively normal body composition. METHODS: The study was a cross-sectional population study in 170 Caucasian children (91 boys and 79 girls), with a mean age of 9.9+/-0.6 y (range 8.5-10.9 y) and a mean BMI of 17.4+/-2.6 (range 12.8-28.1). Serum leptin was measured and compared to total body fat as determined by dual-energy X-ray absorptiometry. RESULTS: In the whole population, serum leptin concentrations were highly correlated with total body fat (r=0.83, p<0.001). A stepwise forward multi-regression analysis revealed that the inclusion of other anthropometrical data did not add any significance to the model. Leptin concentrations were significantly higher in girls (5.2 ng/ml) than in boys (3.2 mg/ml; p=0.003). Gender differences still prevailed (p=0.007) after adjusting for number of kilograms of fat tissue. CONCLUSION: This study shows that, already at the young age of 9-11 y, an adult-like pattern of regulation of leptin exists. This indicates similar risk factor dependency of leptin across all age groups.     

Time course and determinants of leptin decline during weight loss in obese boys and girls.

OBJECTIVE: To investigate whether changes in leptin concentrations during weight loss can be explained by gender, puberty, baseline adiposity and changes in adiposity, body composition, rate of weight loss, physical activity and insulin concentrations. DESIGN: A longitudinal study with 9 repeated measures during a 12-week weight loss programme. SUBJECTS: Fifty-three boys and 62 girls (7.9-15.2 years) with body mass index (BMI) standard deviation scores (SDS) of median 2.78 and 2.70, respectively. MEASUREMENTS: Height, weight, fat mass percentage assessed by bioimpedance, Tanner stages, testicular size, physical activity scores, blood leptin (ng/ml) and insulin concentrations (pmol/l) were measured at baseline, and except for Tanner stage and testicular size, repeated regularly during the programme. RESULTS: The weight loss was accompanied by a steep decline in leptin concentrations during the first 10-11 days, followed by a less steep decline until day 82. Leptin declined to 39% in boys and 51% in girls of the level that was expected given the relationship at baseline between leptin and BMI SDS, and the BMI SDS changes during weight loss. The biphasic leptin decline was independent of gender, puberty, baseline adiposity or concomitant changes in BMI SDS, fat mass percentage, rate of weight loss, physical activity scores or insulin concentrations. CONCLUSION: The biphasic leptin decline, which exceeded the level expected, was independent of puberty, baseline adiposity and changes in adiposity, body composition, rate of weight loss, physical activity scores and insulin concentrations. The dissociation of the leptin-weight relationship during weight loss may contribute to the general leptin variability in obese subjects.     

Fat patterning of Santhal children: a tribal population of West Bengal, India

A cross sectional study was undertaken to examine the body composition including fat patterning among 1012 Santal children, aged 5-12 years, in Puruliya district of West Bengal, India. The anthropometric variable measured included height, weight and skinfold thickness of triceps and subscapular. The body mass index (BMI) was also calculated. The measurements were used to estimate body fat percent (%BF) and fat-free mass (FFM) from skinfolds. Fat mass and FFM were each divided by height squared to produce the fat mass index (FMI) and fat-free mass index (FFMI). Maximum gaining of %BF and FFM was found at ages 11-12 years in both sexes. Difference of-FFM between 5 and 12 years of age was found to be highest in girls (18.7 kg) than in boys (14.92 kg). Body fat percentage of girls was significantly (p < 0.05) higher (except in 8 and 9 years old) than that of boys. FMI and FFMI of girls showed different pattern than that of boys. FFM and %BF showed significant (p < 0.01) relationship with all anthropometric variables. Results suggests a clear evidence of sexual dimorphism in fat patterning; girls showing a greater subcutaneous adiposity in comparison with boys. FMI and FFMI, both indices indicate an age-and sex-related variation among Santal children. The data of the present study could be serving as reference data in other studies of Santal children.     

Changes in leptin, insulin and body composition in obese children during a weight reduction program

BACKGROUND: Girls have higher leptin concentrations than boys at all stages of biological development and this is also seen in the state of obesity. Little is known about whether gender and biological development of obese children influence changes in leptin associated with a short-term weight reduction program. OBJECTIVE: To study whether leptin concentration, body composition and insulin levels in obese children were influenced by a 3-week intervention program including diet and sports. STUDY DESIGN: Sixty-two obese children (32 boys and 30 girls) were examined before and after the intervention program. Body composition was measured by bioelectrical impedance and BMI-SDS was calculated. Serum leptin and serum insulin were determined by RIA. RESULTS: Girls had higher leptin levels than boys, before and after the weight reduction program. Body mass, fat mass (FM), leptin and insulin were decreased after the intervention in both sexes. We found a greater change in serum leptin in girls but the change in FM was of greater magnitude in boys. However, percentage changes in leptin were not significantly different between the sexes. Before the intervention, leptin concentrations were correlated with %FM, FM and moderately with BMI-SDS in all children. Only in pubertal boys did correlation of leptin with %FM increase after the intervention (from r=0.57 to r=0.75, p<0.01). Changes in leptin were found to be associated with initial leptin values in boys (r=0.95, p<0.01) and in girls (r=0.93, p<0.01), independent of Tanner stages. CONCLUSION: Serum leptin levels were positively correlated with adiposity in obese children and a diet and sports intervention program decreased serum leptin, insulin and body fat in all children. Changes in leptin were best described by the initial leptin concentration. The increase in correlation of leptin with %FM in obese pubertal boys after the intervention could have its underlying mechanism in an increased sensitivity to leptin and anabolic hormones.     

瘦素和脂联素在儿童肥胖相关性高血压发病中的作用

目的探讨瘦素和脂联素在儿童肥胖相关性高血压发病中的作用。方法基于北京市儿童青少年代谢综合征研究项目的现况调查结果，非随机选择3 502名6~18岁学龄儿童（其中男1 784名，女1 718名）为研究对象，按照超重（包括肥胖）和高血压状态将研究对象分为4组，正常体重正常血压组（对照组，1 497名）、正常体重高血压组（HBP组，125名）、超重但血压正常组（OB组，1 349名）和超重合并高血压组（OB+HBP组，531名）。通过比较4组人群血清瘦素和脂联素水平，以及瘦素和脂联素与血压之间的相关回归分析，探讨其与肥胖和血压之间的关系。结果超重肥胖人群BMI、血压、胰岛素和瘦素水平显著升高，脂联素水平降低。HBP组与对照组BMI、瘦素、脂联素水平差异无统计学意义。OB组和OB+HBP组与对照组比较，BMI、SBP、DBP、胰岛素和瘦素水平升高，脂联素水平降低，与HBP组比较仍可见BMI、胰岛素和瘦素水平升高，脂联素水平降低。与OB组比较，OB+HBP组BMI和胰岛素水平及男性的瘦素水平明显升高。血压与年龄、BMI、胰岛素、瘦素均呈显著正相关（r=0.260~0.643,P<0.01），与脂联素呈显著负相关（r=-0.171~-0.332, P<0.01）。但在调整胰岛素或BMI后，瘦素、脂联素与血压的相关性减弱或消失。结论 超重人群血压、胰岛素及瘦素水平均高于对照人群，脂联素水平低于对照人群。瘦素、脂联素可能通过肥胖或胰岛素抵抗与血压相关。     

No relationship between leptin and cortisol in obese children and adolescents

Recent findings have shown that leptin downregulates the steroid producing system in the adrenal. We studied the interactions of leptin, insulin and cortisol in obese children and adolescents at different stages of maturation. In 44 boys (age 11+/-3.1 yr, body mass index [BMI] 29+/-5.3 [mean +/- SD]) and 35 girls (age 11.4+/-2.6 yr, BMI 29+/-4.3), blood levels of leptin, insulin, cortisol, and glucose were determined. Fat mass (FM) was calculated by bioelectrical impedance. No significant differences were found between boys and girls with respect to humoral and anthropometric characteristics. When children were divided according to maturation stage (prepubertal, pubertal, and late/postpubertal) insulin was higher in the more mature groups (p<0.01) and leptin was higher in the pubertal group (p=0.03). In the prepubertal and pubertal groups, the expected positive relationship between adiposity and leptin was found although the magnitude of this association decreased with maturity. In none of the groups studied was cortisol significantly correlated to leptin. Insulin (p=0.03) and glucose (p=0.01) were positively associated with cortisol in the prepubertal group after adjustment for adiposity. However, in the pubertal group an inverse correlation was found between insulin and cortisol (p=0.03), and between insulin and glucose after control for adiposity. In the late/ postpubertal group, no significant correlations were found between estimates of adiposity and humoral parameters even after adjustment for gender. Stepwise multiple regression failed to detect a significant influence of cortisol to explain the variation in leptin, and vice versa. BMI contributed to the variation in leptin (adj. R2 =0.275, p<0.0001), and glucose added 5% to the variation in cortisol (p=0.03). The results do not confirm the inverse association between leptin and cortisol found in adults. Although BMI reflects levels of leptin, it is likely that several other factors in conjunction with fatness modulate the relationship with leptin. Whether leptin per se exerts an influence on the hypothalamic-adrenal-adipo axis remains to be investigated in longitudinal studies.     

Three-Year Follow-up Study on Serum Leptin Levels in GH Deficient Children with GH Replacement Therapy

Interactions between GH and leptin have been extensively studied. However, results of long-term GH therapy on serum leptin levels in GH-deficient children were not consistent. Moreover, no such reports were available in Japanese children with this disease. We studied 35 Japanese patients with GH deficiency (26 boys and 9 girls, mean age: 9.8 ± 6.2 yr old), of whom 6 patients with complete and 29 with incomplete GH deficiency were identified by GH provocation test. Serum leptin levels, percent of ideal body weight (%IBW) and percent fat (%fat) were determined at 0, 1, 3, 6, 12, 18, 24, and 36 mo after beginning GH therapy. Baseline levels of %fat and leptin were significantly higher in girls than boys (P<0.05), though serum leptin did not change throughout the study period in either group. Further, %IBW did not change significantly, whereas %fat exhibited significant changes after 6 mo in boys and remained virtually constant thereafter for up to 3 yr. In summary, serum leptin levels did not change in GH-deficient boys and girls during the 3-yr period after the start of GH replacement therapy, despite a decrease in %fat after 6 mo of therapy in the boys. Thus, it is conceivable that long-term GH replacement therapy can be employed without an effect on normal leptin secretion.     

No evidence for leptin as an independent associate of blood pressure in childhood and juvenile obesity

We studied whether leptin is an independent associate of blood pressure in obese children and adolescence. 102 obese children (48 girls, age: 11.6 +/- 2.22 yr; body mass index [BMI]: 27.45 +/- 4.4; blood pressure: 122.5 +/- 11.1/64.7 +/- 10.6 mm Hg and 54 boys, age: 11.5 +/- 2.4 yr; BMI: 27.6 +/- 4.4; blood pressure: 122.5 +/- 13.2/60.9 +/- 8.1 mm Hg [mean +/- SD]) were investigated. Serum leptin and insulin were measured by RIA; glucose was determined enzymatically. Fat mass (FM) was calculated by bioelectrical impedance. Leptin was higher in girls than in boys (p=0.018) but no significant gender differences were found with respect to indices of adiposity and systolic blood pressure (SBP). Children were divided into three groups, according to pubertal stage (Group 1: prepubertal, 32 boys/13 girls; Group 2: pubertal, 17 boys/25 girls; Group 3: late/postpubertal, 5 boys/10 girls). SBP and DBP correlated with body weight in the whole group (r=0.49, p<0.0001, and r=0.27, p=0.004). In Group 1, BMI showed the highest correlation to SBP; in Group 3 no indices of adiposity were related to SBP. In no case was leptin significantly associated with SBP after adjustment for adiposity. In Group 2, glucose was significantly associated with SBP after adjustment for body weight. In Group 3, however, no correlations were found between SBP, DBP and metabolic characteristics, perhaps due to small sample size. Stepwise multiple regression revealed that body weight and glucose contributed to the variation in SBP in the whole group (R2=0.31, p<0.0001). Insulin accounted for almost 8% of the variation in DBP (R2=0.08, p=0.0034). Body weight contributed significantly to SBP in boys (R2=0.39, p<0.0001) and girls (R2=0.24, p< 0.001). The results imply that body weight contributes independently to the variation in blood pressure. Glucose and insulin contribute to mean blood pressure to some extent, but our data do not support the assumption that leptin per se serves as an independent predictor of blood pressure in obese children and adolescents.     

Prevalence of acanthosis nigricans in relation to anthropometric measures: Community‐based cross‐sectional study in Korean pre‐adolescent school children

Background: This cross‐sectional study was performed to assess the prevalence of acanthosis nigricans (AN) across various anthropometric measures and to identify the cut‐offs for anthropometric indices of adiposity for development of AN in Asian preadolescent school children. Methods: Body mass index (BMI), percentage weight for height (PWH), percentage body fat (PBF), and AN of the neck were evaluated in children in the fifth grade of all elementary schools in one metropolitan, Korean city (2117 boys and 1916 girls, mean age 10.9 ± 0.6 years, mean BMI 18.6 ± 3.3 kg/m²). Results: The prevalence of AN was 8.4% in boys and 5.1% in girls, and was proportional to the BMI, PWH, and PBF. The prevalence of AN rose steeply in the 80th and 90th percentiles of the BMI, PWH, and PBF in boys and girls, respectively. According to receiver operating characteristic analysis, AN was observed in boys with BMI >22.2 kg/m², and in girls with BMI >21.2 kg/m², which are below the current criteria for childhood obesity (local BMI 95th percentile and International Obesity Task Force BMI 30 kg/m²). Conclusions: AN has a good correlation with level of adiposity, and was already present in overweight children that were not considered obese by definition.