Relation of serum leptin and insulin-like growth factor-1 levels to intima-media thickness and functions of common carotid artery in children and adolescents with type 1 diabetes

BACKGROUND AND AIM: Leptin and insulin-like growth factor-1 (IGF-1) have been suggested to be involved in the pathogenesis of atherosclerosis. The aim of this study was to evaluate the relationship between serum leptin, IGF-1 and intima-media thickness (IMT) and functions of common carotid artery (CCA) in children and adolescent patients with type 1 diabetes. MATERIAL AND METHODS: Serum leptin and IGF-1 levels were measured in 45 diabetic patients (23 girls and 22 boys). Age, diabetes duration as well as major cardiovascular risk factors, including anthropometric and metabolic parameters, were matched between girls and boys. The relation of serum leptin and IGF-1 levels to CCA structure and functions were measured by ultrasonography as IMT, cross-sectional compliance (CSC), cross-sectional distensibility (CSD), diastolic wall stress (DWS) and incremental elastic modulus (IEM). RESULTS: Serum leptin levels of diabetic girls were higher than those in the boys (21.8 +/- 14.5 microg/l vs 8.9 +/- 10.6 micro/l, p = 0.002). However, the difference for serum IGF-I levels was not significant between diabetic girls and boys (240.7 +/- 96.8 ng/ml vs 234.7 +/- 93.2 ng/ml; p > 0.05). In all subjects, leptin levels were correlated with CSC (p = 0.04), CSD (p = 0.04) and IEM (p = 0.01), and IGF-1 levels were only correlated with CSC (p = 0.01). Leptin did not show any correlation with ultrasonographic measurements in both girls and boys separately. IGF-1 was correlated with CSC (p = 0.001), CSD (p = 0.002) and IEM (p < 0.001) in boys but not in girls. In a multivariate regression model, IGF-1 emerged as independent correlates for mean CSD and IEM in boys but not in girls. CONCLUSION: Serum leptin and IGF-1 levels in children and adolescent patients with type 1 diabetes are associated with functions of common carotid artery, and the association of IGF-1 levels is influenced by sex.     

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.     

Correlates of adiponectin and the leptin/adiponectin ratio in obese and non-obese children

Adiponectin is an adipocyte secreted protein that has been reported to increase fatty acid oxidation and improve insulin sensitivity. Our aim was to study the relationship between adiponectin and leptin, body fat, insulin and lipoproteins in obese compared to non-obese children matched for age and gender. Adiponectin serum concentrations were significantly lower in the obese compared to the non-obese children (9.1+/-3.7 vs 17.1+/-12.3 microg/ml, p <0.05), in contrast to serum leptin concentrations which were greater in the obese compared to the non-obese subjects (31.8+/-11.1 vs 8.2+/-5.7 ng/ml, p <0.001). When considered as a single group to assess adiponectin concentrations over a spectrum of body size, adiponectin values correlated inversely with body weight (r = -0.33, p <0.05) and BMI (r = -0.35, p <0.05). Adiponectin values correlated directly with HDL-C (r = 0.47, p <0.005), but not with total cholesterol, IGF-I, or leptin binding activity. Since leptin and adiponectin change inversely in relation to BMI, the leptin/adiponectin (L/A) ratio was determined as a potential index relating adiposity to the development of complications of obesity. The L/A ratio was eight-fold greater in the obese compared to the non-obese children, and correlated more strongly with BMI (r = 0.779, p <0.0001) and with HDL-C (r = -0.53, p <0.001), than did adiponectin alone. The L/A ratio also correlated significantly with triceps skinfold thickness (TSF) (r = 0.77, p <0.001) and percent body fat (r = 0.79, p <0.0001) in non-obese children. These data suggest that adiponectin concentrations are already differentially regulated in childhood obesity. The index of increased leptin concentration corrected by reduced adiponectin values (L/A ratio) merits investigation as a marker for morbidities associated with childhood obesity.     

Serum leptin level in children with atopic dermatitis-treated topical steroids

Leptin, the obese gene product, is a 16-kDa peptide hormone secreted by adiposities. Systemic administration of exogenous glucocorticoids has been found to increase circulating leptin levels. In this study, we aimed to assess serum leptin in children with atopic dermatitis (AD)-treated with local steroids. Twenty children with AD were included during the 2001-2002 time period. The study was conducted prospectively. Atopy was defined as the presence of at least one aeroallergen-specific immunoglobulin E (IgE) antibody. Serum leptin was determined using a commercially available radioimmunoassay kit with 3.4-8.3% intra-assay and 3.0-6.2% interassay coefficients of variation, and 0.5 ng/ml sensitivity. Fourteen boys and six girls with AD, the mean age of the patients was 3.1 +/- 2.2. Forty-three percentage of the family histories for atopy were positive, 60% of the cases passive smoking histories were positive. In seven patients the aeroallergen-specific IgE were positive. All 20 patients treated clobetasone 17-butirate (0.05%). There was no significant difference in serum leptin between patients (mean +/- s.d.: 4.6 +/- 3.8), and controls (mean +/- s.d.: 6.2 +/- 3.6) (p > 0.05). Local steroid does not influence circulating leptin levels, suggesting that regulation of body weight is unaffected.     

Serum leptin levels in obese Indian children relation to clinical and biochemical parameters

OBJECTIVE: To evaluate serum leptin levels in obese Indian children and its correlation to anthropometric and biochemical parameters. DESIGN: Cohort study. SETTING: Referral tertiary hospital. METHODOLOGY: Leptin levels were measured in 36 children (26 boys, age 1.5 to 15 years) and 37 adults (21 men, age 25 to 69 years) with obesity and 29 normal weight controls (15 children and 14 adults). RESULTS: Leptin levels were higher than controls in obese children (19.4 +/- 6.4 ng/mL against 5.4 +/- 1.7 ng/mL, p = 0.0001) and obese adults (18.9 +/- 6.4 ng/mL against 7.8 +/- 5.6 ng/mL, p = 0.0001). Leptin levels were higher than males in obese girls (23.5 +/- 1.7 ng/mL against 18.0 +/-7.6 ng/mL, p = 0.040) and women (21.3 +/- 4.4 ng/mL against 15.8 +/- 7.4 ng/mL). Leptin levels correlated with body mass index, waist circumference and waist to-hip ratio. A positive correlation was observed between serum leptin and cholesterol, triglycerides and LDL-cholesterol. No correlation was seen with fasting blood glucose and HDL-cholesterol. CONCLUSIONS: Leptin levels correlate significantly with anthropometric and laboratory parameters in obese children. There is a need for further studies on the role of leptin in childhood obesity and metabolic syndrome.     

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.     

Serum leptin levels in patients with progressive central precocious puberty.

Leptin is a metabolic signal that may be involved in signaling adequacy of energy metabolism for the onset of reproductive function. The aim of this study was to investigate the relationship between leptin serum levels and pubertal development in girls with progressive central precocious puberty (CPP). We investigated longitudinally 14 girls with CPP before and during treatment with depot leuprorelin acetate. Mean (+/-SEM) chronological age and bone age at start of therapy were 6.0+/-0.6 y and 9.5+/-0.7 y, respectively. Leptin was determined by RIA. Girls with CPP showed no significant difference in leptin levels at pretreatment and after 1 and 2 y of treatment compared with healthy girls of the same body mass index (BMI). Mean leptin SD score adjusted for BMI was 0.31+/-0.4, 0.24+/-0.2, and 0.49+/-0.3, respectively (not significant). In a stepwise regression analysis model with BMI, bone age, chronological age, basal and stimulated LH, estradiol, dehydroepiandrosterone, androstenedione, and clinical pubertal signs, BMI was the only parameter that showed a significant correlation with leptin (p = 0.006). In conclusion, these data suggest that serum leptin levels are not significantly elevated at the onset of CPP compared with normal girls. Treatment with depot gonadotropin releasing hormone agonist seems to have no influence on leptin concentrations. As in normal girls, serum leptin levels in girls with CPP are mainly determined by BMI. Thus, we have no evidence that alterations of leptin are related to premature onset of puberty.     

The relationship between different subcutaneous adipose tissue layers, fat mass and leptin in obese children and adolescents

We studied the relationships of subcutaneous adipose tissue layers (SAT-layers), body fat mass (FM) and waist-to-hip ratio (WHR) with leptin in obese children and adolescents. Twenty-nine obese children and adolescents (12 boys: age: 11.3 +/- 3.7 yr; body mass index [BMI]: 28.5 +/- 4) and 17 girls (age: 12.2 +/- 2.2 yr; BMI: 29.8 +/- 4.7) (mean +/- SD) were studied. FM was estimated by bioelectrical impedance. SAT-layers were determined at 15 different body sites from 1-neck to 15-calf by the Lipometer optical device. Leptin and insulin were determined by RIA. Maturity was associated with a greater thickness of certain SAT-layers from the upper body and with a lower thickness of SAT-layers from the abdominal region and lower extremities. Significant correlations were found for all estimates of adiposity and leptin (all p<0.001). Waist and hip circumferences were not correlated to leptin after adjustment for FM. SAT-layers from the upper body were significantly and positively correlated to leptin. Multiple regression analysis revealed FM as a main contributor to the variation in leptin (R2=0.53, p<0.0001). FM together with SAT-layers 5-front chest and 13-rear thigh explained 72% of the variation in leptin (p<0.0001). In a body fat distribution model, hip circumference together with SAT-layers 4-upper back and 2-triceps explained 75% of the variation in leptin (p< 0.0001). The results suggest that SAT-layers and their topography are main determinants for leptin in obese children and adolescents. Maturity in obese children is associated with higher values of upper body SAT-layers and lower values of abdominal and lower extremities SAT-layers. Whether leptin is under the control of certain subcutaneous adipose tissue depots from the upper body remains to be elucidated by longitudinal studies.     

0～14岁儿童血肥胖抑素含量及其意义

目的了解0～14岁儿童血肥胖抑素(Leptin) 水平.方法对154名(男 78名,女 76名)0～14岁健康非肥胖儿童(38例)和超重/肥胖儿童(39例)的Leptin分布、性别/年龄变化趋势、与人体测量学参数(腰围、腰臀比、瘦体重、全身体脂含量、体脂百分数、BMI/Kaup指数)和血胰岛素水平的相互关系进行了研究.结果 (1)健康非肥胖儿童Leptin值为1.01～29.92 (ng/ml),均值为2.99±2.13 (ng/ml).90%可信限范围,男童为1.36～14.21 (ng/ml),女童为1.74～21.17 (ng/ml).血浆与血清Leptin值差异无显著意义;(2)超重/肥胖儿童血Leptin值明显高于非肥胖儿童(P＜0.001).(3)Leptin性别差异有显著意义(P=0.023),在非肥胖儿童中更明显(P=0.004).多元回归分析表明,加入体脂因素后性别因素不再与Leptin 水平相关(P=0.138,0.241,0.990),而BMI、体脂含量和体脂百分数的影响差异有显著意义(P＜0.001);(4)Leptin值与年龄存在相关关系(P=0.005),超重/肥胖组更著,女性随年龄增长而升高的趋势更明显(P=0.001).青春期前期Leptin值开始上升,女性明显高于男性(P=0.045).不同年龄组其Leptin值明显不同(P＜0.001).(5)Leptin值与BMI、体脂含量和体脂百分数显著正相关、与瘦体重相关关系弱,男童与腰臀比不相关,女童存在相关关系.曲线回归方程(Quadatic)比直线相关方程更好的指示上述相关.(6)0～7岁儿童Leptin值与出生体重明显相关(P=0.001),自学龄期后无相关关系(P=0.456).(7)Leptin值与空腹胰岛素水平呈正相关(P＜0.001).结论儿童血Leptin值的发育与脂肪发育及重聚规律一致.     

Elevated serum selenium in diabetic children

Twenty-seven diabetic children, 16 girls and 11 boys, 5-18 years of age, with a duration of the disease ranging from 2-15 years, comprised the study group. Thirteen children with a similar age and sex distribution, living in the same area served as healthy controls. All 40 children had a normal growth pattern. The mean serum selenium concentration in the diabetic children, determined by neutron activation analysis, was 7.4 +/- 0.8 micrograms/100 ml (mean +/- SD) and in the healthy controls 6.5 +/- 0.8 micrograms/100 ml. The difference between the two groups was statistically highly significant (p less than 0.01). Boys and girls in both groups had nearly identical mean serum selenium levels and no correlation was observed between the selenium concentrations and either the age, weight or height of the children or the indicators of diabetic control. The selenium status in diabetic children has not been reported previously. The possibility of elevated serum selenium in diabetic children in response to altered lipid metabolism is discussed.     

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。     

Serum leptin concentrations in relation to pubertal development

OBJECTIVES: The amount of adipose tissue influences pubertal development and fertility in girls. A candidate for mediating this is the hormone leptin, derived from adipocytes. This work was carried out to determine whether the leptin concentration in serum is regulated during pubertal development. SUBJECTS AND METHODS: Serum concentrations of leptin were determined by radioimmunoassay in a sample of 252 healthy children representing all pubertal stages. RESULTS: Serum leptin concentrations correlated directly with age (r = 0.53), body mass index (BMI) (r = 0.71), and weight for height SD score (r = 0.44) in girls and with BMI (r = 0.33) and weight for height SD score in boys (r = 0.36). Leptin concentrations increased with pubertal development in girls, resulting in significantly higher concentrations at pubertal stages 4 and 5 than at the prepubertal stage, whereas there was no change in the boys. CONCLUSIONS: Serum leptin concentrations increased during pubertal development in the girls, but remained constant in the boys. Whether the increase in serum leptin concentrations in girls is of importance for, or a consequence of, pubertal development is still to be determined.     

Possible effect of leptin on renal magnesium excretion in adolescent patients with type 1 diabetes

BACKGROUND: Hypomagnesaemia and hyperleptinemia are common in patients with diabetes. Moreover, it has been demonstrated that leptin stimulates diuresis and natriuresis. The aim of this study was to evaluate the relationship between serum leptin, serum magnesium (Mg) and urinary Mg/urinary creatinine levels in patients with type 1 diabetes. METHODS: Serum leptin and Mg and urinary Mg/urinary creatinine levels were measured in 67 patients with diabetes (33 girls and 34 boys). The age, diabetes duration, anthropometric and metabolic parameters of the subjects were matched between girls and boys. The relation of serum leptin levels to serum and urinary Mg/urinary creatinine levels was assessed. RESULTS: Serum leptin levels of girls with diabetes were higher than those of the boys (14 +/- 5.3 microg/L vs 5.8 +/- 1.5 microg/L, P < 0.001, respectively). The differences for serum Mg and for urinary Mg/urinary creatinine levels were not significant between girls and boys with diabetes. Leptin levels were correlated with urinary Mg/urinary creatinine levels in both girls and boys (r = 0.39, P = 0.02 and r = 0.37, P = 0.03, respectively). In a multivariate regression model, leptin emerged as independent correlates for mean urinary Mg/urinary creatinine in both girls and boys with the total variance explained being 14%, and 15%, respectively. CONCLUSION: The data suggest that serum leptin might be related to increased urinary Mg loss in patients with type I diabetes.     

Estimation of body fatness by air displacement plethysmography in African American and white children

The purpose of this study was to determine the ability of air displacement plethysmography (ADP) to estimate body fatness in prepubertal and early pubertal African American and white children. One hundred nineteen nonoverweight and overweight boys (N = 56) and girls (N = 63), age (mean +/- SD) 9.8 +/- 1.7 y, body mass index 25.9 +/- 7.6 kg/m2 (range, 14.2-47.0 kg/m2), and mean percent body fat (%BF) by dual-energy x-ray absorptiometry (DXA) 39.2 +/- 11.7% (range, 12.2-57.5%), were studied. %BF by ADP was compared with DXA %BF estimates and with body fat by several field methods: skinfold thicknesses using the Slaughter et al. equations (Hum Biol 60: 709-723, 1988), bioelectrical impedance analysis (BIA) using the Houtkooper et al. equation (J Appl Physiol 72: 366-373, 1992), and a predictive equation using skinfold thicknesses, BIA, and weight (Goran et al.: Am J Clin Nutr 63: 299-305, 1996). All methods used to estimate %BF were significantly correlated with DXA (all p < 0.0001), with r2 ranging from 0.85 (skinfold measurements) to 0.95 (ADP). ADP using the Siri equation underestimated %BF by -1.9% (p < 0.001); the Bland-Altman limits of agreement (defined as +/-2 SD) were +/-7.4%. %BF by ADP-Siri underestimated %BF by DXA by 3.0% for girls (p < 0.001) and by 0.6% for boys (NS). Agreement between body fat estimation by ADP and DXA did not vary with age, race, or pubertal stage. Application of the age-adjusted Lohman model to ADP significantly increased the magnitude of the underestimation to -6.9% (p < 0.0001). Prediction of %BF by the Slaughter skinfold thickness equation showed no significant mean bias for the overall data, but significantly underestimated %BF in girls (-3.7%) while overestimating %BF in boys (+2.4%) with wide limits of agreement (+/-17.7%, p < 0.01 versus ADP). %BF by the Houtkooper BIA equation or Goran model underestimated %BF to a significantly greater degree than ADP (Houtkooper, -8.1%; Goran, -10.1%; both p < 0.0001 versus DXA or ADP). Determination of %BF from ADP using the Siri model slightly underestimates %BF as determined by DXA in girls, but appears to be superior to existing field methods both in accuracy and limits of agreement. Because of the ease with which it can be performed, ADP may prove useful for investigations of adiposity in children.     

The relationship between leptin, metabolic hormones, exercise and body composition in adolescents

During adolescence, little is known about the relationship between leptin and metabolic hormones and how these are modified by body composition and exercise. This study determined: 1) the relationships between leptin, triiodothyronine, cortisol, and insulin, and 2) whether these relationships were modified by body composition and exercise. Fasting hormonal concentrations were assessed from 80 girls and 80 boys, aged 11-18 yr. In a multiple regression model, including the hormones and gender, only gender and insulin were significant predictors of leptin (R2 = 0.394; p <0.001). In a second model, including body fat and exercise, the levels of body fat, gender, free triidothyronine and cortisol explained 59.6% of the variance in leptin (p <0.05). The results suggest that in adolescents, the relationship between leptin and insulin is mediated by body fat. Leptin is negatively associated with cortisol in boys and with thyroid hormones in girls; these hormones possibly interact to sustain normal growth and maturation.     

Changes of serum allopregnanolone levels in the first 2 years of life and during pubertal development.

Allopregnanolone is the best characterized among neurosteroids, and its role in the control of neuroendocrine axes has attracted increasing interest recently. However, there is no available information about circulating levels of allopregnanolone during infancy, childhood and puberty. We studied two groups of children: 1) those aged between 0 and 2 y (n = 72), and 2) those aged between 6 and 18 y, at different Tanner's stages (n = 82). In each of these patients, serum allopregnanolone, progesterone, cortisol, and dehydroepiandrosterone levels were evaluated after informed consent; allopregnanolone was measured by RIA after acid extraction on cartridge. There was no significant variation of serum allopregnanolone levels either in male and female children during the first 2 y of life. Furthermore, although serum dehydroepiandrosterone levels showed a significant decrease, inversely correlated with age of the children (p < 0.01), serum cortisol and progesterone levels showed a significant age-related increase during the first 2 y of life. Cortisol and allopregnanolone levels were positively correlated (p < 0.01). During puberty, we observed a progressive increase in serum allopregnanolone levels in both boys and in girls, which were higher at Tanner' s stage IV-V (0.7+/-0.01 nM; mean +/- SEM) than at stages I-II (0.32+/-0.02 nM; p < 0.01); mean levels were significantly higher at puberty than in the first 2 y of life (p < 0.01). Furthermore, during puberty, serum progesterone and dehydroepiandrosterone levels also increased progressively with age in both boys and girls. Allopregnanolone and dehydroepiandrosterone levels were positively correlated throughout puberty. The present results indicate that serum allopregnanolone levels do not change during the first 2 y of life but increase during pubertal development, suggesting that this steroid may be involved in the adaptive neuroendocrine mechanisms related to puberty.     

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.     

Body composition during the first 2 years of life: an updated reference

Normative body composition during the first 2 y of life was derived from a prospective study of 76 children. We present 1) fat free mass (FFM) and its components, and fat mass (FM), 2) incremental growth rates partitioned into chemical components, and 3) age-specific and gender-specific constants for converting chemical and physical components into FFM for children during the first 2 y of life. A multicomponent model based on measurements of total body water (TBW), total body potassium (TBK) and bone mineral content (BMC) was used to estimate FFM and FM at 0.5, 3, 6, 9, 12, 18, and 24 mo of age. TBW was determined by deuterium dilution, TBK by whole body counting, and BMC by dual energy x-ray absorptiometry. FFM was higher in boys than girls between 0.5-18 mo of age (p < or = 0.05). Percent FM increased on average from 13 to 31% between 0.5 and 3-6 mo, and then gradually declined. Percent FM was significantly higher in girls than in boys at 6 and 9 mo of age (p < or = 0.02). The components of FFM on a percentage basis changed with age (p = 0.001), but not gender. The protein content of FFM increased gradually with age, while TBW declined (p = 0.001). As a percentage of FFM, osseous mineral increased from 2.0 to 3.4% in boys and from 2.1 to 3.3% in girls between 0.5 and 24 mo (p = 0.001). Density and potassium content of FFM increased gradually with age (p = 0.001). These normative body composition data provide an updated reference upon which to assess normal growth and nutritional status of pediatric populations representative of mixed feeding groups during the first 2 y of life.     

Leptin levels in children with insulin dependent diabetes mellitus

Leptin, a product of the ob gene, is a polypeptide hormone produced in adipose tissue that informs the brain about the amount of energy storage of body fat. It has very important effects on neuroendocrine functions and energy expenditure. The aim of our study was to determine leptin levels of children with insulin dependent diabetes mellitus (IDDM), which is known to affect body metabolism, and to investigate the relationship between duration of the disease, insulin dosage, HbA1c levels, body mass index (BMI), serum lipids and IGF-1 levels. Sixteen patients with IDDM (chronological age 13.8 +/- 2.6 years) whose HbAlc levels were 10.2 +/- 1.9 %, BMI 21.2. +/- 2.7 kg/m2, insulin dosage 0.9 +/- 0.4 U/kg/day and duration of the disease 6.7 +/- 2.6 years, and 12 healthy controls (13.4 +/- 2.6 years) were included in the study. Fasting plasma leptin levels were measured by radioimmunoassay method. The mean plasma leptin levels of the patient and the control groups were 19.1 +/- 7.6 ng/ml and 6.1 +/- 2.9 ng/ml, respectively, and significant difference was found between the two groups (p < 0.05). No correlation was found between leptin values and IGF-1, cholesterol, HDL-cholesterol, LDL-cholesterol, triglyceride levels, atherogenic index, insulin dosage or HbA1c levels in the patient group. A weak statistical correlation was determined between BMI and leptin levels in the IDDM group (r = 0.28, p < 0.05). A positive correlation was also found between leptin levels and the duration of the disease (r = 49, p < 0.05). As a result, it seems that leptin levels of children with IDDM differed from the levels of the control group significantly, and that the duration of insulin therapy was responsible for this difference.