Efficiency of Estrogen Replacement Therapy in Osteoporosis
Estrogen therapy has been taken as a settled approach for both prevention and treatment of osteoporosis, especially in post-menopausal women as well as for the treatment of symptoms associated with menopause. Recent studies suggest that nuclear factor kappa-B ligand/receptor activator of nuclear factor kappa-B/osteoprotegerin system plays a signi cant role in osteoclastic activity regulation, with receptor activator of nuclear factor kappa-B ligand signaling in the presence of macrophage colony stimulating factor leading to increase in osteoclastic differentiation and functioning while osteoprotegerin neutralizing receptor activator of nuclear factor kappa-B ligand. Estrogen acts by increasing osteoprotegerin levels, and decreasing macrophage colony stimulating factor and receptor activator of nuclear factor kappa-B, thereby reducing bone resorption. Furthermore, estrogen is also known to be causing increased calcium absorption through gut and kidneys. The use of estrogen therapy in patients of osteoporosis is also considered to be highly cost effective. On the negative side, studies have shown that oral estrogen therapy can lead to complications like cholelithiasis, thrombophlebitis and pulmonary embolism, the most detrimental being endometrial cancer. But studies have shown that it can be virtually eliminated with the addition of progesterone in the cyclic combined regimen. Majority of bene cial effects occur with long term use of estrogen therapy, but the compliance by most of women appears to be poor and is usually due to lack of awareness, misconceptions, advice of physician and phobia of side effects. Additional studies should therefore be conducted to evaluate in detail the causes of non-compliance and strategies to improve compliance. The bene t of quality of life improvement with estrogen therapy should be taken into account and further evaluated via studies.