Serum leptin concentration during puberty in healthy nonobese adolescents
Braz. j. med. biol. res
;
36(10): 1293-1296, Oct. 2003. tab, graf
Article
in English
| LILACS
| ID: lil-346483
ABSTRACT
Data obtained during the past five years have indicated that there are important age- and gender-based differences in the regulation and action of leptin in humans. To study the physiological changes of leptin during puberty in both sexes, and its relationship with body composition and sexual maturation, we measured leptin concentrations in 175 healthy adolescents (80 girls, 95 boys, 10-18 years of age), representing all pubertal stages. We excluded individuals with a body mass index (BMI) below the 5thor above the 95th percentile relative to age. Serum concentrations of leptin were determined by a monoclonal antibody-based immunofluorimetric assay, developed in our laboratory. Body composition was determined by dual-energy X-ray absorptiometry. Pubertal stage was assigned by physical examination, according to Tanner criteria for breast development in females and genital development in males. Leptin concentration in girls (N = 80) presented a positive linear correlation with age (r = 0.35, P = 0.0012), BMI (r = 0.65, P < 0.0001) and percentfat mass (r = 0.76, P < 0.0001). In boys (N = 95) there was a positive correlation with BMI (r = 0.49, P < 0.0001) and percentfat mass (r = 0.85, P < 0.0001), but a significant negative linear correlation with Tanner stage (r = -0.45, P < 0.0001) and age (r = -0.40, P < 0.0001). The regression equation revealed that percentfat mass and BMI are the best parameters to be used to estimate leptin levels in both sexes. Thus, the normal reference ranges for circulating leptin during adolescence should be constructed according to BMI or percentfat mass to assure a correct evaluation
Full text:
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Index:
LILACS (Americas)
Main subject:
Puberty
/
Sex Characteristics
/
Leptin
Type of study:
Observational study
/
Prevalence study
/
Risk factors
Limits:
Adolescent
/
Child
/
Female
/
Humans
/
Male
Language:
English
Journal:
Braz. j. med. biol. res
Journal subject:
Biology
/
Medicine
Year:
2003
Type:
Article
Affiliation country:
Brazil
Institution/Affiliation country:
Universidade Federal de Säo Paulo/BR
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