Leptin and adiponectin levels in pubertal children: relationship with anthropometric variables and body composition.

Background: Adipocytokines play an important role in controlling energy homeostasis, and in various metabolic processes related to obesity. The aim of this study was to describe serum leptin and adiponectin concentrations in a sample of pubertal Spanish children and to evaluate their association with anthropometric parameters and body composition.

Methods: The study included 833 pubertal boys and girls.

Sex hormone-binding globulin and lipid profile in pubertal children.

Men and women have different lipid profiles throughout life, related to changes in sex hormones; and this has been associated with sex-related differences in the prevalence of coronary heart disease. The influence of sex hormone changes during puberty on the lipid profile has been reported, but levels of sex hormone-binding globulin (SHBG) (the specific plasma binding protein of sex hormones) have not been evaluated even though its regulatory role might be crucial. The aim of this study was to analyze the relationship between sex hormones and SHBG and changes in plasma lipid levels during puberty.

Sex hormone-binding globulin levels and metabolic syndrome and its features in adolescents.

Background: Low levels of sex hormone-binding globulin (SHBG) are associated with obesity, insulin resistance, and metabolic syndrome (MS) in men and women, and it has been suggested that SHBG could be a useful marker for MS risk.

Objective: The aim of this study was to analyze the relationship of SHBG levels with MS and its components in Spanish adolescents.

Methods: The sample population of this cross-sectional study was comprised of 386 male and 429 female adolescents, aged 12-16 yr.

Fat intake influences the effect of the hepatic lipase C-514T polymorphism on HDL-cholesterol levels in children.

Polymorphisms in the hepatic lipase gene have been associated with variability in plasma HDL-C concentrations, but contradictory results have been reported regarding the effect of diet on this association in adults. In our study, we examined whether dietary fat intake modified the association between lipid levels and the C-514T polymorphism in the hepatic lipase gene (LIPC C-514T) in prepubescent children. The LIPC C-514T polymorphism was determined by PCR and restriction analysis in 1260 healthy school children, aged 6-8.

Genetic determinants of plasma HDL-cholesterol levels in prepubertal children.

Introduction: Genetic determinants have been related to variation of high-density lipoprotein cholesterol (HDL-C) levels, but the extension of this association remains controversial. In our study, we analyzed the contribution of several polymorphisms on HDL-C-related genes to variation of plasma HDL-C in prepubertal children.

Methods: We studied 1269 (641 males and 628 females) 6-8 years old healthy children, who participated in a cross-sectional study examining cardiovascular risk factors in Spain.

High-density lipoprotein cholesterol and paraoxonase 1 (PON1) genetics and serum PON1 activity in prepubertal children in Spain.

Background: Oxidative stress plays an important role in atherosclerosis. Paraoxonase 1 (PON1) is a high-density lipoprotein (HDL)-associated enzyme that inhibits low-density lipoprotein (LDL) oxidation and may play a protective role against coronary heart disease. The aim of this study was to analyze the relationship between HDL-cholesterol (HDL-C) and PON1 in a Spanish prepubertal population with high plasma HDL-C levels.

Hormone levels in 12- to 15-year-old boys and girls in Spain and their relationship with anthropometric variables.

Objective: To determine hormone levels in a population-based sample of pubertal children and evaluate their association with anthropometric parameters.

Methods: Sex steroid levels were assessed using RIA and IRMA.

Results: In boys, changes in weight and height across the period were accompanied by changes in testosterone and SHBG.

Dehydroepiandrosterone sulfate (DHEA-S) distribution in Spanish prepuberal children: relationship with fasting plasma insulin concentrations and insulin resistance.

Background: The aim of this study was to analyze dehydroepiandrosterone sulfate (DHEA-S) levels in a population-based sample of Spanish prepuberal children and to investigate the relationship between DHEA-S and insulin.

Methods: 854 (440 boys and 414 girls) randomly selected prepuberal children were included in our study after a sampling. Children were 6 to 8 years old and were classified for the analysis in half-year intervals.