Pituitary Disorders and Osteoporosis

Table 1

Mechanism of bone effects of certain hormones acting in pituitary disorders.

Hormone	Physiological effect	Effect of hormone excess	Effect of hormone deficit
GH, IGF-1	Anabolic effect, influence bone size, OB stimulation, OC promotion, necessary for attaining normal PBM	Thickening of bone,; ↑cortical BMD	↓PBM, ↓BMD
Prolactin	None	OC stimulation,; ↓trabecular BMD	None
Cortisol	None	OB inhibition,; OC stimulation,; ↓trabecular BMD,; ↓PBM	None
Sex steroids	Necessary for attaining normal PBM	None	OC stimulation,; ↓trabecular BMD
Thyroxine	Necessary for bone growth and attaining normal PBM	↓PBM, OC stimulation	↓PBM

OB—osteoblast; OC—osteoclast; PBM—peak bone mass; BMD—bone mineral density.