Leptin, insulin and TNF-alpha in weight loss.

Forty-eight morbidly obese patients were placed on a very low calorie (800 kcal) formula diet (OPTIFAST) for a 10-week period with the goal of achieving 10% weight loss within this time. Weekly serum leptin measurements were performed to determine whether changes in this adipose protein would serve as a useful marker of acute and chronic weight loss compliance. In the basal state, serum leptin averaged 56.

Short-term modulation of the androgen milieu alters pulsatile, but not exercise- or growth hormone (GH)-releasing hormone-stimulated GH secretion in healthy men: impact of gonadal steroid and GH secretory changes on metabolic outcomes.

Gonadal steroids are known to alter GH secretion as well as tissue metabolism. The present study was designed to examine the effects of short term (2- to 3-week) alterations in gonadal steroids on basal pulsatile (nonstimulated) and exercise- and GH-releasing hormone-stimulated GH secretion, urinary nitrogen excretion, and basal and exercise-stimulated oxygen consumption. Two protocols were conducted, which reflect a total of 18 separate studies.

Differential sex steroid negative feedback regulation of pulsatile follicle-stimulating hormone secretion in healthy older men: deconvolution analysis and steady-state sex-steroid hormone infusions in frequently sampled healthy older individuals.

The healthy aging male reproductive axis tends to exhibit a progressive decline in serum concentrations of biologically available testosterone with gradual concomitant reciprocal increases in both LH and FSH concentrations. However, relatively little is known about the sex steroid-mediated negative feedback regulation of physiologically pulsatile gonadotropin release in general, and episodic FSH release in particular, in older males. To examine the steroid hormone negative feedback control of pulsatile FSH secretion in healthy older men, we applied multiparameter deconvolution analysis to serum FSH (immunoradiometric assay) profiles obtained by sampling every 10 min over 24 h during steady state (4.

Alterations in pulsatile luteinizing hormone and follicle-stimulating hormone secretion in idiopathic oligoasthenospermic men: assessment by deconvolution analysis--a clinical research center study.

To investigate the nature of neuroendocrine disturbances of the hypothalamo-pituitary-gonadal axis in idiopathic male infertility, we studied 14 infertile men with oligoasthenozoospermia (OLIGO) and 15 age-, body mass index-, and community-matched euspermic controls by blood withdrawal at 10-min intervals for 12 h to encompass basal (8-h) and exogenous GnRH-stimulated (4-h) pulsatile release of LH and FSH (by immunoradiometric assay) as well as testosterone (by RIA). Deconvolution analysis was used to estimate endogenous LH and FSH half-lives, secretory burst frequency, amplitude, duration, and mass. OLIGO men exhibited normal serum concentrations of total, free, and percent dialyzable testosterone and estradiol, but distinct dynamic alterations within the LH and FSH axes; namely (P < 0.

Neuroendocrine alterations in the somatotropic and lactotropic axes in uremic men.

To investigate the pathophysiology of altered growth hormone (GH) and prolactin secretion in endstage renal disease, we sampled blood at 10-min intervals for 24 h and applied deconvolution analysis to calculate hormone half-lives and pulsatile secretion rates. Two-site immunoradiometric assays were employed to quantitate presumptively intact GH and prolactin in nine middle-aged men with chronic renal failure and 14 gender-, age-, body weight- and community-matched controls. We observed that the half-lives of endogenous GH and prolactin were prolonged significantly in uremia: for GH, control 17 +/- 1.