Relationship of Serum Leptin Level with Chronological Age and Body Mass Index in Adolescent Girls (original) (raw)
Related papers
International Journal of Obesity, 1997
OBJECTIVE: Leptin, the product of the ob gene, is present in higher concentrations in blood of obese subjects than of lean subjects. There is scarce information on the role of leptin in the pathogenesis of human obesity and little is known about leptin serum levels in obese children. DESIGN, SUBJECTS AND MEASUREMENTS: To evaluate the in¯uences of age, sex, pubertal development and weight excess on serum leptin levels, we have studied 390 obese subjects (OS) and 320 normal weight subjects (NWS) aged 5±16 y. Fasting insulin concentrations were assayed in NWS, and an oral glucose tolerance test was carried out in OS and total insulin area under the curve (TIA) was calculated. RESULTS: Log-transformed values of leptin serum concentrations appeared to be distributed according to an acceptable Gaussian pattern. As observed in adults, serum leptin concentrations in children and adolescents were also increased (4±5 times) in OS as compared to NWS. In both males and females, subdivided according to pubertal stages, serum leptin varied signi®cantly in stage IV±V as compared to the lower stages, with a reduction in males and an increase in females. On comparing the two sexes, greater serum leptin concentrations were observed in females of both NWS and OS. A signi®cant linear correlation was found in both groups, subdivided according to sex and pubertal stage, between log values of serum leptin and standard deviation scores (SDS) of body mass index (BMI), and logtransformed relative body weight (RBW). Using partial correlation analysis in subjects subdivided according to sex and pubertal stages, log values of serum leptin and fasting insulin values, adjusted by age and SDS of BMI, correlated signi®cantly with a weaker correlation in males than in females. In OS, the leptin concentrations correlated better with TIA than with fasting insulin. A weight reduction program (WRP) was carried out in 141 OS and signi®cant reductions of serum leptin and fasting insulin were observed, showing a reduction of RBW. There was a correlation between the reduction of RBW and of serum leptin, but not of fasting insulin. No variation was found in non-responsive OS. RBW reduction correlated with leptin, but not with insulin (fasting and TIA), evaluated before the therapeutic program started. CONCLUSION: As observed in adults, obese children and adolescents have higher serum leptin concentrations. However, several conditions should be taken into account when evaluating leptin concentrations in children. There are differences, independent of BMI, relative to pubertal stage and sex, females having greater leptin concentrations than males. There is evidence of a possible role for leptin in the effectiveness of a weight reduction program in OS.
2011
The aim of the study was to analyze the relationship between leptin serum levels, body mass index and certain parameters of lipid and carbohydrate metabolism in children and adolescents with various degree of obesity. We assessed 86 children and adolescents (45 boys and 41 girls) between 6 and 18 years of age within the Ist Pediatric Clinic from Târgu Mure ; 68.60% of the children were overweight, 29.07% had class I obesity and 2.33% had class II obesity. Leptin serum levels were measured and compared with BMI, age and parameters of carbohydrate and lipid metabolism (blood glucose, cholesterol, triglycerides, HDL cholesterol, and LDL cholesterol). Leptin serum levels were increased in all overweight and obese adolescents: we found leptin serum levels of 45.69 ± 28.04 ng/mL in boys, and significantly higher values (72.96 ± 22.02 ng/mL) in girls. These values were positively correlated with BMI (r = 0,34 in boys and r = 0,44 in girls). A positive correlation was found between leptin, ...
2004
The rising epidemic worldwide in overweight and obese children requires urgent attention. Leptin has been found to be associated with body weight control and possibly affects insulin sensitivity. Since insulin resistance is associated with obesity in adults and possibly in adolescents, we set out to investigate the association of plasma leptin level with various anthropometric indices, body fat mass (FM), lipids, and insulin resistance (IR) index in nondiabetic adolescents. DESIGN: A cross-sectional study from three high schools in Taipei City in Taiwan. SUBJECTS: A total of 402 nondiabetic subjects (162 boys and 240 girls; age range, 10-19 y; mean age, 15.871.9 y, and mean body mass index (BMI), 24.874.6 kg/m 2 ) were recruited. MEASUREMENTS: The fasting plasma leptin, plasma glucose, insulin, lipids, and anthropometric indices including height, weight, waist (WC) and hip circumferences, and waist-to-hip ratio (WHR) were examined. Total body FM and percentage body fat (FM%) were obtained from dual-energy X-ray absorptiometry. The homeostasis model was applied to estimate the degree of IR. RESULTS: The plasma leptin levels were significantly higher in girls (17.45710.13 ng/ml) than boys (8.8176.71 ng/ml, Po0.001). The plasma leptin levels were positively correlated to BMI, WC, WHR, FM, FM%, and triglycerides (TG). The IR index was positively correlated to BMI, WC, WHR, FM, FM%, TG, and leptin. Using the multivariate linear regression models, we found that plasma leptin remains significantly associated with IR index even after adjusting for age, gender, BMI, FM, WC, Tanner stage, and TG. CONCLUSION: Plasma leptin was associated with IR index independent of age, gender, BMI, FM, WC, Tanner stage, and TG. Plasma leptin levels in adolescents could be a predictor for the development of the metabolic syndrome disorders and cardiovascular diseases.
Serum leptin levels in overweight children and adolescents
British Journal of Nutrition, 2009
Leptin is an adipocyte-secreted hormone which plays a key role in energy homeostasis. Our aim was to determine the relationship between serum leptin and clinical and biochemical features in overweight children and adolescents. Overweight children and adolescents followed in this Unit with serum leptin ascertained were included. Clinical, biochemical and abdominal ultrasound data were analysed. Statistical analysis was performed by t test, X2. Pearson's correlation and linear regression. One outlier of serum leptin was excluded to perform correlation and regression. Serum leptin was determined in 357 patients. At the first visit, the mean age was 9-5 (so 3.2) years and mean BMI z-score was 1.72 (so 1-34) (girls 1.71 (So 1-16); boys 1.72 ). Serum leptin levels were significantly related to: sex (mean: girls 48.0 ng/ml, boys 34-4 ng/ml; P=0.003); Tanner stage (mean: I-IE 37-0ng/ml, III-V 45-2nglml; P=0.035); systolic blood pressure (mean: normal 41.3ng/ml. high 44-0ng/ml; P=0.009); BMI z-score (r 0-136: P=0-010); C-peptide (r 0-17: P=0-002); insulin (r 0-34; P<0-001); homeostasis model assessment of insulin resistance (HOMA-IR) (r 0-25; P<0.001) and aspartate aminotransferase (r -0-12; P=0-023). In the multivariate analysis (with leptin as the dependent variable and sex. Tanner stage, BMI z-score, systolic blood pressure, aspartate aminotransferase. C-peptide. insulin and HOMA-IR as independent variables), sex and BMI were determinant factors. The present study in overweight children and adolescents showed that being female and greater BMI were significantly and independently associated with increased -erum leptin. In this large cohort other associations with leptin described in the literature can be discharged.
Serum leptin through childhood and adolescence
Clinical Endocrinology, 1997
OBJECTIVE Leptin is the protein product of the recently cloned ob gene, that has been implicated in the control of body weight and thermogenesis, but also independently stimulates the reproductive axis. As major changes in body composition and gonadal function occur during human adolescence, we have assessed serum leptin concentration through childhood. SUBJECTS AND MEASUREMENTS Serum leptin was measured in a radioimmunoassay in samples from 235 healthy children from 5 to 18 years of age. Its relationship to body mass index (BMI) (expressed as standard deviation score (SDS)) and the changes in concentration both within and between sexes over the stages of puberty were analysed. RESULTS Serum leptin was present at similar concentrations in both sexes over the prepubertal years and increased in parallel into early puberty (breast stage (B) 2, genital stage (G) 2). Thereafter serum leptin in the boys declined to a nadir in G5. In contrast in girls, leptin remained constant in mid-puberty rising to a peak at B5. Factors influencing leptin (BMI SDS, age and testicular volume) were assessed therefore in the pre-and peripubertal stages (B1-2, G1-2) compared to the later pubertal stages (B3-5, G3-5). In all groups, leptin was positively correlated to BMI SDS (r 2 ¼ 38-41% in girls, r 2 ¼ 31-35% in boys). However in B1-2 and G1-2, leptin was also positively related to age, which contributed a further 27% and 20% respectively to the variability. In B3-5, age only accounted for an additional 5% in leptin variability. In contrast in G3-5, leptin was related positively to BMI SDS (r 2 ¼ 35%) and negatively to testicular volume (r 2 ¼ 24%). CONCLUSIONS The influence of BMI on leptin is a significant factor throughout the prepubertal and pubertal years of both sexes. The additional negative effect of testicular volume in the boys contributes to the sexual dichotomy in leptin concentration at the completion of puberty. The similar rise in leptin over the prepubertal years into early puberty in both sexes, related not only to BMI SDS but also independently to age, would suggest that leptin may have a facilitatory role in human pubertal development.
The Journal of Clinical Endocrinology & Metabolism, 1997
It is commonly accepted that at least in girls puberty starts when a minimum level of body mass or a certain amount of body fat are present. However the precise signal by which adipose stores inform the hypothalamus of the degree of energetic reserves is unknown. Leptin is a hormone produced by the adipocytes to regulate food intake and energy expenditure at the hypothalamic level. To understand whether leptin is the adipose tissue signal that allows puberty, 789 normal children of both sexes, age 5-15 yr, were transversally studied. Leptin levels, as well as gonadal and gonadotropins levels, were analyzed in addition to the determination of auxological parameters. In an age-related analysis, leptin levels in girls rose from 5-15 yr (from 4.3 Ϯ 0.4 to 8.5 Ϯ 0.9 g/L) in parallel with body weight. Boys always had lower leptin levels than girls (3.3 Ϯ 0.3 g/L at 5 yr), but they rose in parallel with weight until 10 yr (5.3 Ϯ 0.7 g/L), when a striking decrease was observed until 15 yr (3.0 Ϯ 0.3 g/L). In girls, leptin was the first hormone to rise followed by FSH and later by LH
Metabolism, 1998
Leptin has been demonstrated to reflect body fat mass (FM) in humans, but the regulation of leptin levels during childhood growth and development is poorly understood. We studied the relation between plasma leptin, fasting insulin, insulin sensitivity, and resting energy expenditure in 22 healthy prepubertal children and 27 adolescents. Body composition was assessed by the H2(18)O-dilution principle, insulin sensitivity by a hyperinsulinemic (40 mU/m2/min)-euglycemic clamp, and energy expenditure by indirect calorimetry. Plasma leptin in prepubertal children (9.3 +/- 2.0 ng/mL) was not different from that in pubertal adolescents (10.9 +/- 2.2 ng/mL). Plasma leptin correlated with FM (r = .77, P < .001). There were no gender differences in leptin after controlling for FM differences. In prepubertal and pubertal subjects, plasma leptin correlated with fasting insulin independently of FM (r = .60, P < .001), but did not correlate with insulin sensitivity independently of body fat content. Leptin showed no relationship to resting energy expenditure after adjusting for body composition. The present cross-sectional evaluation of normal children shows that (1) plasma leptin reflects body fat content, (2) leptin concentrations are similar between prepubertal children and pubertal adolescents, (3) there are no gender differences in leptin independent of adiposity, and (4) leptin correlates with fasting insulin but not with insulin sensitivity. Contrary to animal data, our cross-sectional results in healthy children do not suggest a role for leptin in puberty or a female-related leptin resistance as reported in adults. It remains to be determined at which stage of human development the sexual dimorphism in leptin becomes evident.
EFFECT OF BODY MASS INDEX ON SERUM LEPTIN LEVELS
Background: Leptin is product of ob gene, an adipose tissue derived hormone that plays a key role in the regulation of body fat mass by regulating appetite and metabolism while balancing energy intake and energy expenditure. The objective of the study was to evaluate possible association between serum leptin levels and Body Mass Index (BMI) of gender in adult age group. Methods: Two-hundredseventy subjects aged 20-50 years were randomly selected from general population of Abbottabad. The subjects were grouped on the basis on BMI (89 normal, 92 overweight, and 89 obese). After complete evaluation, demographic data was recorded and BMI. Non-fasting venous blood samples were drawn to measure serum leptin and serum glucose levels. The data were analysed using SPSS-15 calculating mean, percentage, independent t-test and chi-square test. Correlation and regression curve analysis were obtained, and p and r values were calculated. Results: Serum leptin levels and differences between genders were significant in all body mass indices. For normal BMI group the mean values for leptin were 2.6±1.5 ηg/ml in men, and 17.3±10.2 ηg/ml for women. For Group-2 mean leptin levels in men were 9.9±6.8 ηg/ml and in women were 34.8±13.6 ηg/ml. For Group-3 BMI comprising obese subjects mean values for men were 21.3±14.2 ηg/ml and for women were 48.21±21.2 ηg/ml (p<0.001). Conclusion: A progressive increase in serum leptin concentration was observed with an increase in BMI. Significant difference between leptin concentrations in either gender was found in normal, overweight and obese subjects.
Effect of Variations in Body Mass Index on Serum Leptin Levels in
2016
Objective: To measure the serum leptin and insulin levels and assess that how body mass index and affects these levels in pre and post menopausal obese and non-obese women. Place and duration of study: It was a comparative study. Sampling was done from various Hospitals, organizations and residential areas. The experimental work was carried out at the department of Biochemistry & Molecular Biology and Center for Research in Experimental and Applied Medicine-1 (CREAM-1), NUST, Rawalpindi, Pakistan and was spread on duration of 18 months. Methodology: The samples for the study were obtained from healthy eighty subjects & divided into premenopausal and postmenopausal groups of 40 each which were further sub-divided into obese and non obese based on the body mass index (cutoff BMI value = 25 kg/m). Fasting blood sugar, triglycerides, serum Insulin and serum leptin were measured along with BMI and HOMA IR. Data was analyzed for frequencies, percentages, means and standard deviation ( ± S...