Endocrine Abstracts

Background: Primary hypothyroidism affects about 3% of the general population (5.1% women and 0.9% men). The majority of people are treated adequately with levothyroxine. However about 5–10% of hypothyroid patients (representing between 75 000 and 150 000 adults in the UK) continue to experience profound and sometimes disabling symptoms, such as fatigue/depression/impaired cognition, in spite of being adequately replaced biochemically. Before any trial of alternatives to ...

Leptin is regarded as an essential adipokine for controlling energy homeostasis, caloric intake reduction and increase of caloric expenditure by negative feedback mechanisms via receptors in the hypothalamus. Puberty is said to be triggered by leptin, which signals the hypothalamus that adequate fat reserves are available for initiation of energetically costly process of reproduction. Leptin activates gonadotropin releasing hormone (GnRH) system, which stimulates luteinizing h...

During the time of puberty, thyroid hormones (THs), thyroxin (T4) and triiodothyronine (T3), influence growth and developmental processes by working in association with growth hormone (GH), insulin like growth factor-I (IGF-1), glucocorticoids, insulin and gonadal steroids. THs have a direct effect on GH secretion, which stimulates IGF system. It has been suggested that THs control increase in bone length through synergy with GH. This investigation determ...

Ghrelin receptor GHSR1α is expressed in hypothalamo–pituitary–gonadal tissues. Ghrelin reduces GnRH secretion in pre-pubertal period and concentrations of ghrelin are positively correlated with testosterone at adulthood. Nevertheless, the role of ghrelin in affecting pituitary and gonadal functions during normal pubertal development remains elusive. A possible correlation between ghrelin and LH, FSH, testosterone and inhibin B was examined in boys (n=55...

The G protein coupled receptor of obestatin GPR39 is expressed in pituitary and gonads, indicating its possible role in regulation of pituitary and testicular function. The present study examined a possible association of obestatin with LH, FSH, testosterone, and inhibin B at puberty. Blood samples were collected from 10 to 20 years old boys (n=557) and concentrations of obestatin, LH, FSH, testosterone, and inhibib B were determined using specific ELISA. Data were an...

Puberty, one segment of a larger developmental continuum in humans, is characterized by major transformations in body such as highest growth, sexual development and distribution of fat in different body regions. Leptin is regarded as an essential adipokine that regulates intake of food, expenditure of energy and body fat mass. It is well known that alterations in nutritional states markedly influence growth hormone (GH) secretion, which in turn regulates linear growth, muscle ...

The maturation of hypothalamo-pituitary-gonadal (HPG) axis causes the onset of puberty, which stimulates the development of secondary sex characteristics and changes in the size and composition of the body. Furthermore, the size of the thyroid gland increases and its function also changes as an adaptation to the requirements of the transformation of child to an adult. It has also been reported that the thyroid hormones including thyroxin (T4) and triiodothyronine (T3) have a f...

Leptin, a key metabolic signal controlling both energy intake and energy reserves, informs the brain about energy stores of the body to initiate reproductive processes at puberty. Thyroid hormones are important determinant of overall energy expenditure, basal metabolic rate and thermogenesis. The present study examined the relationship between leptin and thyroxine (T4) and triiodothyronine (T3) in boys (n=540) between the age of 1 and 20 years. B...

The reawakening of the hypothalamo-pituitary-gonadal (HPG) leading to attainment of sexual maturation and reproductive capacity is influenced by several internal and external factors. Amongst external factors, adverse physical or psychological conditions may alter the timing of onset of puberty. The present study examined the effect of persistent and severe physical stress on timing of onset of puberty. The study included non-working school/college going and working boys of 10...

Adrenarche is a normal maturational event that in humans occurs at around 6–8 years of age. During adrenarche, a new zone of the adrenal cortex, the zona reticularis, is developed, resulting in increased production of adrenal androgens, androsteindione, DHEA and DHEAS. The increase in the secretion of adrenal androgens causes the appearance of axilliary and pubic hair, a brief increase in linear growth velocity and bone maturation, and the development of the brain. The pr...