Defining Growth Hormone Status in Adults with Hypopituitarism

Abstract

The identification of adults with severe growth hormone (GH) deficiency (GHD) is not straightforward. The insulin tolerance test remains the gold standard diagnostic test, although other stimuli such as GH-releasing hormone-arginine are gaining acceptance. Insulin-like growth factor-I has a poor diagnostic sensitivity in adult-onset GHD, but is more useful in the subgroup of adults with childhood-onset GHD. Therapeutic developments include increasing recognition of the need to continue GH therapy beyond final height in young adults with severe GHD on retesting. Consensus guidelines have provided a useful algorithm to identify individuals requiring retesting and the number of tests needed. The concept of partial GHD, recognized by paediatric endocrinologists for many years, is being examined in adults with hypothalamic-pituitary disease. Preliminary evidence suggests that this entity is associated with metabolic and anthropometric abnormalities intermediate between those in severe GHD and in healthy controls. It remains to be seen whether this subgroup will derive benefit from GH therapy. To date, therapeutic benefits of GH have been demonstrated only in adults with severe GHD. It is, therefore, imperative that these individuals are unequivocally identified; the diagnosis becomes more uncertain in the presence of obesity, increasing age, and in the absence of additional pituitary hormone deficits.

Evaluation of the Quantitative Expression and Correlation between Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH) During Follicular phase in Primary Infertile Women of Reproductive Age

“…Gynaecologists, having established that the male partner is fertile, consider a woman to be infertile if the woman has not conceived after twelve months of contraceptive free intercourse, if the female is under the age of 34, or the woman has not conceived after six months of contraceptive free intercourse if the female is over the age of 35 [2]. Primary infertility describes a state in which a woman has never been able to conceive [3]. Between 8 and 12 percent of couples around the world have difficulty conceiving a child at some point in their lives, and in some areas, the figure reaches one-third or more [4].…”

Treatment for 24 months with recombinant human GH has a beneficial effect on bone mineral density in young adults with childhood-onset GH deficiency

“…Several studies have yielded evidence to support the efficacy of GH in preventing the adverse changes in body composition (26,30,31). Thus, the practice of discontinuing GH in all patients after attainment of adult height is under review and it is suggested that continuation of GH replacement in GHD individuals during the post-pubertal 'transition' phase may alleviate the metabolic complications of GH deficiency, including maturation of bone (32,33).…”

Does the pituitary somatotrope play a primary role in regulating GH output in metabolic extremes?

“…In humans, circulating GH levels are negatively correlated with body mass index. 63,64 Obese patients also show a blunted or absent response to all known GH stimuli, [65][66][67][68][69][70][71] where in some cases these changes can be difficult to differentiate from organic GH deficiency (GHD). 71 Significant weight loss (by exercise/diet or gastric bypass) results in the recovery of circulating GH concentrations.…”

“…63,64 Obese patients also show a blunted or absent response to all known GH stimuli, [65][66][67][68][69][70][71] where in some cases these changes can be difficult to differentiate from organic GH deficiency (GHD). 71 Significant weight loss (by exercise/diet or gastric bypass) results in the recovery of circulating GH concentrations. [72][73][74] Therefore, the metabolic alterations associated with weight gain are thought to be the precipitating events leading to suppression of the GH-axis.…”