Table 5.

Systemic and local regulation pathways and their effect on bone.

	Bone Resorption	Bone Formation
Calcium-Regulating Hormones
1. Parathyroid hormone	↑	↓
2. 1,25-dihydroxyvitamin D	↑	↓
3. Calcitonin	↓	–
Systemic Hormones
1. Glucocorticoids	↓	↓
2. Insulin	–	↑
3. Thyroxine	↑	↑
4. Sex hormones	↓	↓↑a
5. Growth hormones	–	↑
Growth Factors
1. Insulin-like growth factors	–	↑
2. Fibroblast growth factor	↑	↓
3. Platelet-derived growth factor	↑	↑
4. Transforming growth factor-β	↑↓	↑↓
Local Factors
1. Prostaglandin E	↑	↑↓b
2. Interleukin-1	↑	↑↓b
3. Tumour necrosis factor	↑	↑↓
4. Bone morphogenic protein	–	↑↓

^aEffects dependent on age and concentration.

^bEffects dependent on presence and concentration of glucocorticoids.