Role of Growth Hormone and Sex Steroids in Achieving and Maintaining Normal Bone Mass

Abstract

It is now established that adults with growth hormone (GH) deficiency, of childhood or adult onset, have reduced bone mass. GH deficiency is believed to interfere with acquisition of bone mass, although an alternative mechanism is required to explain the reduction in bone mass present in adults who acquire GH deficiency after peak bone mass has been achieved. GH replacement increases bone turnover and may increase bone mass in the longer term, although short-term studies show a decrease in bone mass which can be explained by an increase in bone resorption before new bone formation occurs. Abnormalities of GH secretion have also been implicated in the development of osteoporosis, but the effect of GH treatment on bone mass in such patients is disappointing. Sex steroids have an important role to play in the acquisition of bone mass, and reduced sex steroid levels during adolescence have a deleterious effect on bone mass. The importance of sex steroids in the maintenance of bone mass is illustrated by the development of osteopenia in men and women with hypogonadism, and by the preservation of bone mass by restoration of normal endogenous sex steroid levels, or by treatment with exogenous sex steroid. Sex steroids also influence circulating levels of GH and insulin-like growth factor-1, and the interaction between these hormones is likely to be important in the acquisition and maintenance of normal bone mass.

Deletion of β-adrenergic receptor 1, 2, or both leads to different bone phenotypes and response to mechanical stimulation

“…Among the molecules regulating peak bone mass acquisition and longitudinal growth, IGF-1 plays a central role. Indeed, the growth hormone (GH)/IGF-1 axis is upregulated during the pubertal period (33,34) ; serum IGF-1 levels are directly related to bone growth and peak bone mass acquisition (28)(29)(30) ; IGF-1 is the most abundant growth factor synthesized and stored in bone (35)(36)(37) ; and physiological levels of IGF-BP have anabolic effects on bone. (38) Accordingly, we found that serum IGF-1 and IGF-BP3 were markedly decreased in young Adrb1b2 À/À mice compared with WT, whereas IGF-1 and IGF-2 mRNA levels in bone were normal, suggesting an inhibition of the somatotropic axis and/or a downregulation of liver IGF-1 production in absence of b1-and b2-adrenergic signaling.…”

RNA-seq profiles from grass carp tissues after reovirus (GCRV) infection based on singular and modular enrichment analyses

“…The appropriate level of methionine can improve growth performance and digestion and absorption capacity (Bingrong et al, 2012). Steroid hormones are fat soluble hormones that play roles in maintaining homeostasis (Funder et al, 1997), regulating glucose metabolism (Gupta and Lalchhandama, 2002), immunomodulation (Casto et al, 2001) and ontogenetics (Holmes and Shalet, 1996).…”

Bone mineral status in prepubertal children with constitutional delay of growth and puberty

“…We can only speculate about the possible mechanisms for these findings. The influence of GH/IGF-I on bone mineralization is well documented (16)(17)(18)(19) as it is for the influence of sex steroids (20,21). Causes for CDGP are far from clear.…”