background: the relationship between metabolism and reproduction has been always considered as an important topic in female endocrinology. it seems that leptin is one of the involved factors in infertility. leptin, in addition to regulating body weight plays an important role in regulation of endocrine, reproductive and immune systems. the aim of this stduy is to compare serum and follicular fl...

BACKGROUND Several studies suggest that changes in estrogens and androgens during menopause play a role in the regulation of leptin production. Some authors present hypothesis that sex hormone replacement therapy can modulate leptin levels but up to date evidence shows that the influence of endogenous estrogens, androgens levels and sex hormone therapy on leptin concentration remains uncertain....

BACKGROUND The ob gene product leptin is secreted by fat cells and reflects the content of fat in the body. Leptin and insulin concentrations as well as body weight are interrelated and a direct correlation has been found between these concentrations in humans with normal renal function. Markedly elevated serum leptin concentrations have recently been reported in patients with chronic renal fai...

Adipose tissue secretes leptin, which interacts with receptors in the hypothalamus. In rodent models of obesity, leptin increases metabolism and decreases food intake, which helps to maintain normal body composition. Accurate and precise methods to quantitate circulating leptin concentrations are needed for physiological studies. We developed an RIA to measure leptin in rat plasma, serum, or ad...

Recent studies demonstrated significantly higher serum leptin concentrations in females as compared with males, even after correction for differences in body fat mass. The aim of our study was to measure serum leptin concentrations in a large group of obese children and adolescents to determine the possible role of sex steroid hormones on both leptin serum concentrations and production in human...

AIM To evaluate the effect of maternal diabetes on the concentrations of free and bound leptin at birth and during postnatal adaptation. METHODS Total, bound, and free leptin concentrations and the percentage of free leptin were measured in cord plasma and plasma at 3 days of age of 13 term infants of mothers with gestational diabetes mellitus (GDM) and 13 term infants of healthy mothers. Ges...

The role of gonadotropins, androgens, and insulin in the regulation of circulating leptin levels is obscure. In order to clarify the relationships of these parameters we studied serum leptin levels in 19 healthy control subjects and in 35 hyperandrogenic and hyperinsulinemic patients with polycystic ovary syndrome (PCOS). Serum leptin concentrations did not differ significantly between PCOS pat...

Administration of leptin to rodents results in weight loss through decreased food intake and increased energy expenditure that occurs in part through increased spontaneous activity. In humans, low levels of spontaneous physical activity and below normal plasma leptin concentrations predict subsequent excess weight gain. We recently found that failure to increase nonexercise activity thermogenes...

OBJECTIVE To investigate the relationship between leptin concentrations, gonadotropic hormone concentrations, and body composition during puberty in a Dutch children cohort. DESIGN In a cohort of 98 children, we determined anthropometric measurements, body composition, and concentrations of leptin, FSH, and LH. RESULTS Sex differences were observed from Tanner stage 1 onwards in weight, bod...