Significance of gender of obese children and body weight of parents and siblings for the results of the treatment of obesity in childhood

We studied the influence of family size, family history of obesity, and the obese children's sex on the short and medium term outcome of an obesity therapy in children aged 10.7 +/- 3 years with mean percentage overweight of 41.4 +/- 16.9%. Family parameters such as obesity on other family members, single child families, and sex of the obese children did not influence the decision to stop or to complete therapy. Boys were more successful in weight reduction than girls both after 3-6 months and after 3-5 years; the difference being not significant, however. Children without family history initially were significantly less overweight than those with familial obesity, and they exhibited the best short and medium term results. Children of obese families initially were the fattest ones. They reduced their weight more than average, but they tended to regain weight during the following 3-5 years, reaching the highest levels of overweight after that time. Children without family history of obesity did not regain weight, however. Thus even after good short term results obese children of obese parents should be regarded at risk for relapse and should be checked for years after therapy to prevent weight regain.     

Effects of breastfeeding on weight changes in family-based pediatric obesity treatment

Research indicates that breastfeeding may provide protective effects against the development of obesity; however, breastfed children may still become obese because of the obesogenic environment. This study is designed to examine the effects of retrospective recall of breastfeeding on weight changes in children participating in a 6-month behavioral treatment program for childhood obesity. The independent variable of breastfeeding was defined as children who were exclusively breastfed for 4 weeks (excluding water or medication) versus those who were never breastfed. Child percent overweight and body mass index changes during 6 and 12 months were evaluated for 94 families based on mother report of breastfeeding status using analysis of covariance, controlling for socioeconomic status and initial child weight status. Data were compiled for secondary analysis from pediatric obesity randomized controlled outcome studies evaluating core components of family-based treatments. Results showed that, compared with nonbreastfed (formula) children (n = 28), breastfed children (n = 66) showed significantly larger reductions in (mean +/- SEM) percent overweight at 6 months (-15.2 +/- 1.1 vs -10.2 +/- 1.7, p <.05) and 1 year (-10.3 +/- 1.3 vs -5.9 +/- 1.8, p <.05). Similarly, breastfed children showed greater reductions in body mass index at 6 months (-2.1 +/- 0.19 vs -1.1 +/- 0.28) and 1 year (-0.8 +/- 0.23 vs +0.1 +/- 0.32). Findings suggest the beneficial effects of breastfeeding may extend beyond obesity prevention to include improved outcome in family-based pediatric obesity treatment. Potential mechanisms relating breastfeeding, obesity prevention, and enhanced outcome in pediatric obesity treatment are discussed.     

Short- and intermediate-term results of treatment of children with obesity

We report on the short- and medium-term outcome of obesity therapy in 160 obese children and youths aged 10.7 +/- 3 years, who had been admitted to our department between 1982 and 1984. Mean initial percentage overweight of all children was 41.4 +/- 16.8%. 59 of the children stopped therapy after 1-2 visits, and 101 children (group 1) continued the therapeutic regimen until the end. Our treatment consists of individual consultations with the aim of behaviour modification, and reduction or modification of caloric intake. Within 3-6 months mean weight reduction was 15.3% in the children of group 1. After 3-5 years the medium-term outcome of 48 of these children (group 2) was controlled by phone. Their initial weight reduction had been 17.2%, and after 3-5 years their percentage overweight was still 10.6% below their initial values. During therapy 68% of the children had successfully reduced their overweight below the margin of 20%, and after 3-5 years still 42% of the children remained in this range. Our short term results are similar to those of other studies on obese children, but there are no other comparable publications for medium term outcome. According to our results children should be checked for years after successful obesity therapy in order to prevent relapses.     

Treatment of childhood obesity. Long-term outcome and predictive factors of success in a group of 130 subjects

BACKGROUND: In the last years the prevalence of childhood obesity has notably increased. The treatment of this condition is very difficult, because of the frequent relapses. The aim of our study was to examine the long-term outcomes of different dietary treatments (1200 or 1400 calories or chetogenic diet, derived from the protein sparing modified fast) in children and adolescents with primary obesity, in order to show factors predictive of the long-term success. METHODS: A group of 130 obese children previously undergoing a dietary treatment have been re-evaluated after a 3, 5 and 7 years period from the beginning of the diet. RESULTS: Ninety-seven out of 130 contacted patients (52 males and 45 females; mean age: 16+/-3 years) participated in this study. An overall improvement of the weight indexes has been observed (relative DBMI mean value: -10.5%). About 1/5 of the whole study-group is not overweight anymore. The statistical analysis (ANOVA and multiple regression analysis) showed that the factors positively affecting the long-term outcome were the following: use of chetogenic diet, initial success of the treatment, older age and strong motivation at the beginning of the diet, gender (male) and lack of familiarity for obesity. CONCLUSIONS: It is important, in the clinical practice, to consider the above factors that can predict the long-term success of the dietary treatment, in order to individualize the therapy.     

Childhood obesity. Medical and familial correlates and age of onset

The prevalence of obesity in U.S. children is rising. Etiologic studies have focused on infants and school age children but little is known about obesity in early childhood. To study the development of childhood obesity and its medical correlates, the authors reviewed 175 charts of obese children seen in a nutrition clinic. The 61 study subjects (37% of charts reviewed) had growth records for ages 7 years and less and were without developmental delay syndromes. Thirty-nine (64%) of 61, were girls; ages at presentation were 1 to 14 years. Data collection included previous and presenting weights, heights, medical problems, and evidence of parental and sibling obesity. Study subjects' mean percent of ideal body weight for height (% IBWH) at presentation was 160 percent. Many study subjects had medical problems considered to be related to obesity: 30 percent had asthma, 25 percent elevated blood pressure, and 28 percent hyperlipidemia. Thirty (63%) of 48, study subjects with data on maternal weight and height, had obese mothers and 14 (31%) of 45 had obese fathers. Fourteen (50%) of 28 had one or more obese siblings. Among all study subjects, the proportion of obese (% IBWH greater than 120%) and severely obese children (% IBWH greater than 140%) increased between ages 1 and 7 years. For example, the proportion greater than 140% IBWH was zero percent at 1 year and 3 years; 0.1 at 2 years; 0.2 at 4 years; 0.5 at 5 to 6 years; and 0.6 at 7 years.(ABSTRACT TRUNCATED AT 250 WORDS)     

Childhood obesity increases duration of therapy during severe asthma exacerbations.

OBJECTIVES: Childhood obesity contributes to a wide array of medical conditions, including asthma. There is also increasing evidence in adult patients admitted to the intensive care unit (ICU) that obesity contributes to increased morbidity and to a prolonged length of stay. We hypothesized that obesity is associated with the need for increased duration of therapy in children admitted to the ICU with status asthmaticus. DESIGN: Retrospective cohort study. SETTING: A tertiary pediatric ICU in a university-affiliated children's hospital. PATIENTS: We retrospectively examined data from all children older than 2 yrs admitted to the ICU with status asthmaticus between April 1997 and June 2004. Children were classified as normal weight (<95% weight-for-age percentile) or obese (>95% weight-for-age). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of the 209 children admitted to the ICU with asthma, 45 (22%) were obese. Compared with children of normal weight, the obese children were older (9.7 +/- 4.4 vs. 8.0 +/- 4.3 yrs, p = .02), more likely to be female (60% vs. 37%, p < .01), and more likely to have been admitted to the ICU previously (40% vs. 20%, p = .01). The obese children also had a statistically significant difference in race (more likely to be Hispanic) and in baseline asthma classification (more likely to have persistent asthma). Despite similar severity of illness at ICU admission, obese children had a significantly longer ICU length of stay (116 +/- 125 hrs vs. 69 +/- 57 hrs, p = .02) and hospital length of stay (9.8 +/- 7.0 vs. 6.5 +/- 3.4 days, p < .01). Obese children also received longer courses of supplemental oxygen, continuous albuterol, and intravenous steroids. CONCLUSIONS: Childhood obesity significantly affects the health of children with asthma. Obese children with status asthmaticus recovered more slowly from an acute exacerbation, even after adjustment for baseline asthma severity and admission severity of illness.     

Parental obesity and higher pre-intervention BMI reduce the likelihood of a multidisciplinary childhood obesity program to succeed--a clinical observation

OBJECTIVE: To assess the effects and identify factors associated with success of a combined, structured multidisciplinary weight management program in obese children and adolescents. METHODS: Seventy-seven obese children (age 6-16 years) participated in a 12-month combined dietary-behavioral-exercise intervention. Thirty-seven (age and maturity comparable) obese children who did not participate in the structured program served as controls. Body weight, BMI, and BMI percentiles were measured at baseline, after 6 months, and at the end of the intervention. RESULTS: The combined intervention was associated with a significant decrease in BMI (from 25.9+/-0.4 to 24.5+/-0.4 kg/m2, p <0.0005) and BMI percentile (from 97.3+/-0.2% to 92.6+/-0.9%, p <0.0005). In contrast, obese children who did not participate in the structured program gained weight (from 51.4+/-3.6 to 57.7+/-3.7 kg, p <0.0005), increased their BMI (from 25.2+/-1.0 to 26.6+/-0.9 kg/m2, p <0.0005), and had a non-significant increase in BMI percentiles (from 94.9+/-0.8% to 95.4+/-0.9%, NS). Children with higher BMI percentiles and parental overweight tended to respond less favorably to the combined multidisciplinary program (p <0.01). CONCLUSIONS: A prolonged (12 mo), combined, structured multidisciplinary intervention for childhood obesity resulted in a significant decrease in BMI and BMI percentiles. Higher pre-intervention BMI percentiles and parental obesity were associated with less favorable responses to the combined intervention.     

Low-intensity family therapy intervention is useful in a clinical setting to treat obese and extremely obese children.

AIMS: To study the influence of low-intensity solution-focused family therapy with obese and extremely obese pediatric subjects on body mass index (BMI) z-scores and self-esteem. MATERIALS AND METHODS: Fifty-four obese children, aged 6-17 years, were referred to an outpatient obesity clinic. The families received solution-focused family therapy provided by a multidisciplinary team. Height and weight were recorded; BMI and BMI z-scores were derived. Self-esteem was assessed with a validated questionnaire, "I Think I Am." Parents completed "The Family Climate Scale" assessing family dynamics. RESULTS: Eighty-one percent of the children (n =44, mean age 11.9 years, mean BMI z-score 3.67, range 2.46-5.48) and their parents participated in the follow-up. Eleven children were treated for 6-12 months, and 33 for more than 12 months. On average, the families received 3.8 family therapy sessions. Intervention resulted in a mean decrease in BMI z-score of 0.12 (p =0.0001). Self-esteem on the global scale improved after intervention (p =0.002), and also on sub-scales, depicting physical characteristics (p <0.001), psychological well-being (p =0.026), and relations with others (p =0.046). The Family Climate Scale showed improvement in the sub-scales for Expressiveness (p = 0.002) and Chaos (p =0.002). CONCLUSIONS: Solution-focused family therapy provided by a multidisciplinary team to obese and extremely obese children may prove useful in the clinical setting, with a positive impact on obesity and self-esteem.     

Bone mineral density in childhood obesity

There are several metabolic and hormonal disturbances in childhood obesity. The purpose of this study was to determine the relationship between childhood obesity and bone mineral density (BMD). We studied BMD in 37 obese children and in 37 non-obese children. BMD was measured at L2-L4 level by using dual energy X-ray absorptiometry. BMD was significantly related to age, height and weight. The mean BMD in the obese children and control group was 0.655 +/- 0.175 and 0.626 +/- 0.159 g/cm2, respectively, without any statistically significant difference (p>0.05). There was no correlation between BMD values and osteocalcin or calcitonin levels. According to Tanner's pubertal staging, the mean BMD of pubertal obese children was higher than that of prepubertal obese children. BMD of the pubertal obese children was significantly higher than that of the pubertal control group (p<0.05). Girls had higher mean BMD values than boys. In conclusion, our results show that BMD is not influenced by obesity in children but higher values in puberty were observed in obese children which may due to hormonal changes.     

Exercise therapy and hypocaloric diet in the treatment of obese children and adolescents

Fourteen obese children and adolescents were treated with a combined therapy of low calorie diet and exercise and their progress compared to that of 11 obese children treated with diet only. Children treated with combination therapy were encouraged to perform aerobic exercises daily, for a period of time which was calculated to consume approximately 250 kcal per exercise session. After 4 months of therapy, a significantly (P less than 0.05) larger decrease of % overweight was observed in the group of children treated with diet and exercise (-25 +/- 13.5%) than in those treated with diet only (-15.8 +/- 10.5%). Treatment compliance was better in the group treated with diet and exercise than in the group which followed a low calorie diet only. We think that unsupervised exercise therapy can be successfully combined with a low calorie diet in the treatment of childhood obesity.     

Association of a mutation in the β3-adrenergic receptor gene with obesity and response to dietary intervention in Chinese children

This study aimed to determine whether the Trp64Arg mutation in the beta3-adrenergic receptor beta3-adr) gene is related to childhood obesity and the response to dietary intervention for obesity. The study included 311 healthy children aged 8-11 y selected at random from 4 primary schools in Beijing. Fasting insulin and lipids were measured and anthropometry was carried out for all samples. The mutation of the beta3-adr gene was determined by polymerase chain reaction-restriction fragment length polymorphism analysis. Forty-seven obese children were selected and divided into two groups. One group received dietary intervention (36 subjects); the other served as the control group (11 subjects). After 3 mo of dietary intervention, anthropometry was carried out again in 47 obese children. The frequency of the mutated allele was similar in 73 overweight and 238 normal-weight children (0.18 and 0.17, respectively). Adjusted for age and sex. there was no significant difference in body mass index (BMI) and the levels of fasting lipids and insulin between those with and without the mutation of the 311 children. However, after 3 mo of dietary intervention. increases in weight and BMI were significantly lower in obese children without the mutation than in the control group (2.41 +/- 0.56 vs 4.43 +/- 0.70. p < 0.05: 0.48 +/- 0.24 vs 1.55 +/- 0.35, p < 0.05. respectively), but the changes in weight and BMI in obese children with the mutation were similar to the results in the controls (4.32 +/- 0.69 vs 4.43 +/- 0.70; 1.47 +/- 0.32 vs 1.55 +/- 0.35). CONCLUSION: The Trp64Arg mutation of the beta3-adr gene may predict the result of dietary intervention in obese children to some extent, but it was not a major factor affecting weight in Chinese children.     

Obesity in infants. A series of 14 cases

The infants aged less than two years, though often overweight, are seldom obese with a weight exceeding 2.5 SD above average for their height. This study includes 14 cases of obesity with early onset. The children were referred at age 17 +/- 5.7 months, with a mean height of +1.07 +/- 1.15 SD for age and a mean weight of +4.54 +/- 2.44 SD for height. They were reported as overfed, without any associated abnormality in their prenatal and postnatal history, and without emotional disturbances. In 8 cases, one of the parents was obese. For obtaining a weight decrease in these very young patients, a severely restricted diet has been necessary, with 50-60 cal/kg/day, corresponding in fact to 65-85 cal/kg of the average weight for height when the weight excess is 4 to 9 SD, and sometimes less, and hospital care. This diet, continued for 1 to 8 months, has allowed to reduce the weight excess at the level of +2.66 +/- 1.38 SD for height. It has been harmless, but not well accepted, so that in spite of the good results 10 of the 14 babies and mothers were lost for follow-up. The data show that true obesity is different from common weight excess in infants, is rare and very difficult to manage, and is poorly understood.     

The effect of weight control on lipid changes in obese children

The effects of weight change on serum lipid changes were assessed in a sample of 56 obese children randomly assigned to family-based behavioral obesity treatment vs controls given no treatment. Fasting serum lipid levels, height, weight, and fitness were measured at program entry and after 6 months of treatment. Children assigned to treatment showed significantly greater relative weight and weight changes than children in the control group, and the weight changes were significantly related to reductions in fasting serum triglyceride and total serum cholesterol levels and increases in high-density lipoprotein serum cholesterol. Results after 5 years of follow-up available for a small sample of treated children showed that a change in relative weight and fitness from 6 months to 5 years was also associated with changes in the high-density lipoprotein level. These results suggest that weight control in obese preadolescent children may be associated with improvement in lipoprotein profiles.     

The effect of a combined intervention on body mass index and fitness in obese children and adolescents - a clinical experience

We assessed the effect of a weight management programme on body weight, body mass index (BMI), and fitness in obese children and adolescents. The study was designed as a longitudinal, non-randomised, clinical experience of a 3 and 6 month combined dietary-behavioural-exercise intervention. A total of 177 obese children (age 6-16 years) participated in the 3 month programme, of whom 65 completed the 6 month intervention. A group of 25 age- and maturity-matched obese children who did not participate in the structured programme served as controls. Body weight, BMI, and fitness were evaluated at baseline, and after the 3 and 6 months intervention. Body weight and BMI were significantly reduced ( P<0.05), and endurance time significantly increased ( P<0.0005) following the 3 months intervention. Obese children who continued the programme for 6 months maintained the decrease in BMI and further improved endurance time. In contrast, obese children who did not participate in the structured programme gained weight, increased their BMI, and improved fitness less significantly. Gender, pubertal status, and the degree of obesity had no influence on BMI changes. Children without parental overweight had significantly greater decreases in BMI compared to children of obese parents. CONCLUSION: a combined, structured multidisciplinary intervention for childhood obesity results in decreased body weight, decreased body mass index and improved fitness.     

肥胖儿童血浆同型半胱氨酸含量及动脉病变的研究

目的　探讨单纯性肥胖儿童是否存在高同型半胱氨酸血症和早期动脉粥样病变。方法　68例 6 ~14岁单纯性肥胖症儿童与 26例正常同龄儿童对照,多普勒二维超声检测颈动脉内膜 中层厚度(IMT)、肱动脉血流介导的内皮依赖性扩张功能并探查肝脏形态结构,化学发光法测定血浆同型半胱氨酸。生化分析法检测全套血脂。结果　肥胖儿童右颈总动脉IMT( 0.54±0.13 )mm,右颈内动脉IMT(0.69±0.14)mm,左颈总动脉IMT(0.52±0.12)mm,左颈内动脉IMT(0.67±0.14)mm;正常儿童右颈总动脉IMT(0.45±0.04)mm,右颈内动脉IMT(0.46±0.04)mm,左颈总动脉IMT(0.45±0.05)mm,左颈内动脉IMT(0.46±0 03)mm,肥胖儿童明显增厚(P<0.01)。肥胖儿童肱动脉血流介导的内皮依赖性扩张功能 (11.0±4.3)%,与对照组 (17.5±4.9)%比较,差异有统计学意义(P<0.01)。肥胖儿童血浆同型半胱氨酸含量(7.9±2.7)μmol/L,与正常儿童血浆同型半胱氨酸含量(5.6±2.1)μmol/L比较差异有统计学意义 (P<0.01)。肥胖儿童总胆固醇 (TC)、甘油三脂(TG)、低密度脂蛋白胆固醇 (LDL-ch)、载脂蛋白B(apoB)明显高于对照组,差异有统计学意义(P<0.01);高密度脂蛋白胆固醇 (HDL ch)、载脂蛋白A(apoA)与对照组比较,差异无统计学意义(P>0.05)。58%肥胖儿童存在脂肪肝或脂肪肝倾     

Serum levels of soluble tumor necrosis factor-alpha receptor 2 are linked to insulin resistance and glucose intolerance in children

BACKGROUND: Obesity and insulin resistance are increasingly common problems in children. Tumor necrosis factor-alpha (TNF-alpha) has important effects on lipid and glucose metabolism. This effect may be mediated through soluble TNF-alpha receptor 2 (sTNFR2). OBJECTIVE: To investigate the relationship between insulin resistance and the TNF-alpha system in childhood obesity. CHILDREN AND METHODS: Twenty-one obese and six non-obese children were studied. Body mass index (BMI) z-scores, percent body fat (PBF) and waist to hip ratio (WHR) were determined. Fasting serum levels of total cholesterol, HDL-cholesterol, LDL-cholesterol, TNF-alpha and sTNFR2 were measured. A standard 2-hour oral glucose tolerance test (dose of glucose: 1.75 g/kg, max. 75 g) was done. Insulin resistance (IR) was estimated by fasting plasma insulin, plasma insulin at 120 min, homeostasis model assessment (HOMA) and insulin area under the curve (AUC) from OGTT. Insulin sensitivity was estimated by oral glucose insulin sensitivity (OGIS120). RESULTS: Among the obese participants, one child (5.2%) was found to have diabetes mellitus and four others (21.1%) impaired glucose tolerance (IGT). Obese children had significantly elevated sTNFR2 levels. Furthermore, the group of obese children with IGT and the patient with newly diagnosed diabetes mellitus together (n = 5) had significantly higher levels of serum sTNFR2 (2,865+/-320 pg/ml) than the rest of the obese (2,460+/-352 pg/ml; p = 0.016) or lean (1,969+/-362 pg/ml; p = 0.014) children. Serum sTNFR2 levels correlated positively with insulin AUC, HOMA IR, fasting plasma insulin, plasma insulin at 120 min, total cholesterol and LDL/ HDL ratio, and negatively with OGIS120. Multiple regression analysis revealed that age, WHR, sTNFR2 and LDL predicted 81% of the variability in glucose at 120 min. CONCLUSION: sTNFR2 is a candidate marker of insulin resistance and glucose intolerance.     

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.     

Nutrition, overnutrition, and obesity in the first year of line in Malm?, Sweden.

The feeding pattern, calorie intake, weight and height were studied at various ages during the first 12 months in 243 infants born in Sweden. The feeding pattern and calorie intake was close to that recommended. 0-6% in each age group were found to be obese (20-40% above the standard weight) and 15-23% overweight (10-20% above the standard weight). The mean calorie intake during the months before and when obesity and overweight were diagnosed exceeded the normal by 10% or less. When re-examined at age 2 plus or minus 1/2 years, 50% of those children obese up to 1 year remained so, and only 2 earlier overweight had become obese. 25% of the obese children had one obese parent, compared with 10% of the normal children and overweight ones. The low incidence of overnutrition and the low freqency of obese and overweight infants in this study compared with previous studies support the idea that high calorie intake is of importance in the development of obesity during infancy. Accordingly, overnutrition seems to be one factor, in the multifactorial aetiology of obesity, and reduction of overnutrition can reduce, but not abolish, infantile obesity. Whether the reduction of this will subsequently prevent adult obesity remains to be proved.     

Reduced insulin removal and erythrocyte insulin binding in obese children

To study the relationship between childhood obesity, weight loss, hyperinsulinaemia and the erythrocyte insulin receptor, we measured the plasma concentrations of immunoreactive insulin (IRI) and C-peptide and the binding of ¹²⁵I-insulin to erythrocytes in 12 obese children with a mean age ±SD of 11.4±2.5 years and a mean relative weight score ±SD of 4.8±1.4 and 12 age-matched normal-weight children. Eight obese children were re-evaluated after 1 year's participation in a weight reduction programme. The obese children had higher fasting plasma concentrations of IRI (P<0.01) and C-peptide (P<0.05) and a lower C-peptide to IRI molar ratio (P<0.01) than the normal-weight children. The obese children had in addition a reduced erythrocyte insulin binding (P<0.05 or less) over the physiological range of circulating insulin concentration. There was a negative correlation (r=–0.60; P<0.01) between the insulin tracer binding and the relative weight. The weight reduction programme resulted in a decrease of 1.0SD (P<0.05) in the mean relative weight score. At the end of the therapy the obese children had lower fasting blood glucose levels (P<0.05) and lower plasma IRI concentrations at 90 min (P<0.05) after an oral glucose load than at the onset of therapy. There were no significant differences between the insulin binding characteristics at the commencement and at the end of the treatment. The low C-peptide to IRI molar ratio in obese children provides evidence of a decreased insulin clearance likely to contribute to their hyperinsulinaemia. The inverse relationship between insulin tracer binding and relative weight suggests a mechanism by which weight changes may be directly reflected in the peripheral insulin sensitivity. A moderate weight loss reduces hyperinsulinaemia in childhood obesity but does not normalize the impaired binding of insulin to its receptor.Abbreviations IRI immunoreactive insulin - ID₅₀ concentration of insulin required to reduce the tracer binding of ¹²⁵I-insulin by 50% - OGTT oral glucose tolerance test     

Leptin binding activity (LBA) in plasma of nondiabetic and diabetic adolescents and obese children: relation to auxologic and hormonal data

Leptin circulates in serum bound to high molecular weight proteins. Hypothesizing that leptin binding proteins may regulate the functional efficiency of leptin, we characterized auxologic and hormonal factors that influence leptin binding in three disparate groups: normal adolescents, obese children, and teenagers with type I diabetes mellitus (IDDM). Specific leptin binding activity (sLBA) was assessed by column chromatography after incubation of serum with 125I-leptin in the presence and absence of excess unlabeled leptin. Mean sLBA was 17.0 +/- 7% (SD) in the healthy adolescents (n=41), 6.6 +/-4.3% in the obese children (n=26), and 14.9 +/-7.3% in the diabetic teenagers (n=17). At any value of sLBA, obese children had higher serum leptin levels than non-obese adolescents or diabetic teenagers, consistent with "leptin resistance" in the obese group. sLBA was higher in males than in females only in those with diabetes (18.6 +/- 7.3 vs 10.9 +/- 5.1%, p<0.05). sLBA correlated inversely with serum insulin-like growth factor-I values in the normal group (r= -0.45, p<0.01) and with insulin in the obese children (r= -0.53, p<0.01). There was no correlation between sLBA or serum leptin values and HbA1c, in the diabetic group. The serum leptin concentration was the principal determinant explaining the total variability of sLBA in all three cohorts. However, body mass index (BMI = weight/ height2) accounted for more of the total variability of percent specific binding in the healthy adolescents than in the other groups. We conclude that sLBA reflects circulating leptin levels, body composition, and hormonal milieu. Thus, in addition to leptin, qualitative and quantitative characteristics of leptin binding may play a physiological role in the regulation of appetite and in the "leptin resistance" of obesity.