leptin and Adrenocortical-Hyperfunction

An established fact in the polycystic ovarian syndrome (POS) is an abnormal ovarian steroidogenesis. Though this suggest an intrinsic ovarian defect, the syndrome could also be influenced by factors outside the ovaries. Although of unknown etiology, the POS is one of the most frequent endocrine disorders in the gynecologic practice. The disorder is characterized by ultrasound findings of enlarged polycystic ovaries, hyperandrogenism, menstrual disorders, obesity and including the appearance of infertility. There are a series of mechanisms involved in the extraovarian androgen increase in patients with POS. Among these mechanisms are implicated those of central and peripheral origin, genetic factors and adrenocortical dysfunction. In the same way, the alterations produced could imply genetic, molecular biological, biochemical, physiological and endocrinological factors. Sometimes all these factors could interact at the same time. The high serum androgen level could stop the pituitary gonadotropin production, either as a direct mechanism or as a result of its peripheral conversion. The increased androgens also explain the manifestations of clinical acne, hirsutism, and the detention in follicular ovarian maturation. All these manifestations are related with the menstrual disorders, anovulation, and infertility that these patients develop. The characteristics of the extraovarian POS include the 17-hydroxyprogesterone elevation in response to the ACTH test and the dexamethasone suppression of adrenal androgens. It is possible to improve the ovarian function in some patients with POS. This could be achieved with clomiphene citrate associated with glucocorticoids to induce ovulation.

Topics: 11-beta-Hydroxysteroid Dehydrogenases; 17-alpha-Hydroxyprogesterone; 3-Hydroxysteroid Dehydrogenases; Adrenal Cortex; Adrenal Hyperplasia, Congenital; Adrenocortical Hyperfunction; Adrenocorticotropic Hormone; Adult; Androgens; Catecholamines; Clomiphene; Corticotropin-Releasing Hormone; Cortisone; Dexamethasone; Female; Glucocorticoids; Gonadal Steroid Hormones; Humans; Hydroxysteroid Dehydrogenases; Hyperinsulinism; Hyperprolactinemia; Hypothalamo-Hypophyseal System; Infant, Newborn; Infertility, Female; Insulin Resistance; Leptin; Mineralocorticoids; Obesity; Ovary; Ovulation Induction; Pituitary-Adrenal System; Polycystic Ovary Syndrome; Pseudopregnancy; Steroid 11-beta-Hydroxylase; Steroid 17-alpha-Hydroxylase; Steroids; Sterol Esterase; Stress, Psychological

Administration of growth hormone (GH) induces changes in body composition, namely, increases in both bone and lean mass and a decrease in fatty tissue. However, the contrary issue, i.e. the way in which body composition affects the secretion of GH, is highly controversial. Disease states such as obesity and chronic hypercortisolism are associated with increased adiposity and/or the central distribution of fat. Ageing, characterized by excess adiposity, is also associated with impaired secretion of GH. In these states, both spontaneous and stimulated secretion of GH is severely impeded. At the other extreme, malnutrition and fasting are both associated with increased secretion of GH when confronted with most, if not all, stimuli. As the common factor in all of these situations is the increased or decreased adiposity, or the changes in energy homeostasis, it has been postulated that adipose tissue exerts a relevant role in the control of GH secretion in man. The link between adipose tissue and GH seems to be exerted through at least two signals produced by adipocytes: free fatty acids (FFA) and the recently cloned protein, leptin. An increase in FFA blocks secretion of GH, while a decrease in FFA enhances secretion. Leptin, a hormone whose main role is to regulate the intake of food and energy expenditure, seems to regulate GH secretion by acting at the hypothalamic level. In summary, body composition affects GH secretion by way of the degree of adiposity, and free fatty acids and leptin would appear to be the messages through which adipocytes participate in the regulation of GH secretion. This framework clarifies the metabolic control of GH, a hormone with profound metabolic activities.

Topics: Adipose Tissue; Adrenocortical Hyperfunction; Aging; Animals; Body Composition; Fasting; Fatty Acids, Nonesterified; Growth Hormone; Human Growth Hormone; Humans; Leptin; Nutrition Disorders; Obesity; Proteins; Rats

Leptin and adiponectin are thought to modulate insulin sensitivity and pancreatic β-cell function, but there is limited information regarding the adipokine status of hyperglycemic dogs with hyperadrenocorticism. This study aimed to determine whether alterations in the leptin/adiponectin ratio, insulin sensitivity, and/or pancreatic β-cell function are associated with diabetes mellitus (DM) in dogs with pituitary-dependent hyperadrenocorticism (PDH). A total of 48 client-owned dogs were included in this prospective observational study: 20 dogs with PDH (10 normoglycemic and 10 with DM), 15 dogs with DM, and 13 healthy dogs. The serum concentrations of leptin, adiponectin, resistin, interleukin (IL)-1β, IL-6, IL-10, IL-18, and tumor necrosis factor (TNF)-α were measured, and homeostatic model assessment indices (HOMAs) were calculated and compared among the groups. Serum leptin was significantly higher in PDH dogs with and without DM than in healthy and DM dogs, and it was lower in DM dogs than in PDH dogs without DM. Serum adiponectin was significantly lower in PDH dogs with DM than in healthy and PDH dogs, and it was significantly lower in DM dogs than in healthy dogs. Serum IL-10 was significantly higher in PDH dogs with DM than in healthy and PDH dogs without DM. The leptin/adiponectin ratio was significantly higher in PDH dogs with DM than in normoglycemic PDH dogs. Serum IL-6 concentrations were significantly higher in DM dogs than in healthy dogs. Serum IL-1β concentration was significantly higher in DM dogs than in healthy dogs and PDH dogs with DM and without DM. Serum TNF-α and IL-18 concentrations were not different among groups. The HOMA

Topics: Adiponectin; Adrenocortical Hyperfunction; Animals; Cytokines; Diabetes Complications; Diabetes Mellitus; Dog Diseases; Dogs; Female; Insulin-Secreting Cells; Leptin; Male; Pituitary Gland; Resistin

To measure serum leptin concentration in dogs with pituitary-dependent hyperadrenocorticism and varying degrees of cholestatic disease and determine whether serum levels differed between dogs with pituitary-dependent hyperadrenocorticism and those with gall bladder mucocoele.. Client-owned healthy dogs (n=20), dogs diagnosed with gall bladder mucocoele (n=20) and dogs diagnosed with pituitary-dependent hyperadrenocorticism (n=60) were enrolled. Only dogs of normal body condition score were included. Dogs with pituitary-dependent hyperadrenocorticism were divided into three groups according to the severity of cholestatic disease: normal gall bladder (n=20), cholestasis (n=20) and gall bladder mucocoele (n=20). Serum leptin levels were measured using sandwich enzyme-linked immunosorbent assay.. Serum concentrations of leptin were similar between dogs with gall bladder mucocoele and those with pituitary-dependent hyperadrenocorticism accompanied by gall bladder mucocoele; these concentrations were significantly higher than those in healthy control dogs. In dogs with pituitary-dependent hyperadrenocorticism, circulating leptin concentration significantly increased with the severity of cholestasis: higher in the cholestasis group than the normal gall bladder group and higher in the gall bladder mucocoele group than the cholestasis group.. Elevated circulating leptin concentration was associated with canine pituitary-dependent hyperadrenocorticism and gall bladder mucocoele. Homeostatic imbalance of leptin concentration might be associated with severity of cholestatic disease in pituitary-dependent hyperadrenocorticism.

Topics: Adrenocortical Hyperfunction; Animals; Cholestasis; Dog Diseases; Dogs; Hydrocortisone; Leptin; Pituitary ACTH Hypersecretion

There is a tendency to adiposity in patients with congenital adrenal hyperplasia (CAH) despite physiological corticosteroid doses. This study investigated body fatness in children with CAH under corticosteroid replacement therapy. Seventeen children with CAH (female:male, 9:8; age range 1.6-10.5 years) and 18 controls (female:male, 9:9; age range 1.4-10.2 years) were studied. Serum lipids, leptin, insulin, anthropometry, body circumferences, skinfold thickness, and body fat ratio as measured with bioelectrical impedance analysis (BIA) were the study parameters. Weight standard deviation scores (SDS), body mass index (BMI), BMI-SDS, body circumferences, skinfold thickness, and body fat ratio were higher and leptin was positively correlated with all of the body circumference and skinfold thickness parameters as well as body fat ratio in the study group. Waist/hip ratio was lower in the study group. Body fatness is a serious problem starting in early childhood in CAH patients and further refinement of the glucocorticoid replacement regimens as well as lifestyle measures are needed.

Topics: Adrenal Hyperplasia, Congenital; Adrenocortical Hyperfunction; Androstenedione; Anthropometry; Child; Child, Preschool; Cholesterol; Electric Impedance; Female; Humans; Infant; Insulin; Leptin; Male; Obesity; Progesterone; Skinfold Thickness