Postmenopausal and Senile Osteoporosis: Current Concepts of Etiology and Treatment

Calcium Supplements Increase Bone Mineral Density in Women with Low Serum Calcium Levels During Long-Term Estrogen Therapy.

“…Our subjects in this study had the first bone measurement at 33-48 months after the initiation of CEE therapy and we could not detect an initial increase in BMD. During our experiments, the BMD of women treated with CEE alone did not show significant changes, and our present study confirmed a previous report which suggested that long-term estrogen therapy would arrest or slow bone loss as bone formation is decreased [9]. It has been shown that calcium absorption decreases with age [10].…”

Changes in cortical thickness of the clavicle and serum bone gamma-carboxyglutamic acid-containing protein in the elderly in an island community in western Japan.

“…Although we do not know an overall kinetics of bone loss with age from the present study , the finding that changes in both CTC and biochemical parameters become manifest in 5th and 6th decades of age in women may indicate that endocrinological changes caused by menopause may play some role on bone loss with age (Meema et al . 1965 ;Riggs 1979). Nutritional condition, especially the amount of calcium intake has been shown to affect calcium balance and bone turnover .…”

Metabolic Bone Disease and the Elderly: Current Approach to Diagnosis and Therapy

“…37,38]. In addition to these hormonal factors, the advent of the menopause in the female causes many changes not only because of the decrease in es trogen levels themselves, but because of the effect de creased estrogen levels are believed to have on bone physiology and bone-related hormones: estrogen defi ciency may cause increased calcium release from bone, which, in turn, causes decreased PTH levels, decreased conversion of 25(OH)D to 1.25-dihydroxyvitamin D,and decreased 1,25-dihydroxyvitamin D production with a resulting decrease in calcium absorption [39]. Estrogen deficiency itself may also decrease 25(OH)D-1 -alpha-hy droxylase activity [40].…”

“…Patients with increased PTH levels show a significant increase in the number of os teoclasts and forming surface of bone [59]. Some data support a decreased calcitonin response to calcium infu sion in osteoporosis [60] and implication of calcitonin deficiency with increasing age in the development of osteoporosis [31,34,39,61]. 25(OH)D levels have been reported to be normal [35,58] or elevated [62] in osteopo rosis.…”

“…25(OH)D levels have been reported to be normal [35,58] or elevated [62] in osteopo rosis. Several studies report that serum 1,25-dihydroxyvitamin D levels are significantly lowered in postmeno pausal osteoporosis [35,63,64]; this has been hypothe sized to account for the decreased calcium absorption seen in osteoporosis [35,39]. However, two other studies have not confirmed lowered 1,25-dihydroxyvitamin D status in osteoporosis [65,66], Postmenopausal osteoporosis may involve an un coupling effect of estrogen deficiency superimposed on the age-related decrease in the ability to effectively cou ple bone formation and bone resorption [67], Bone for mation and resorption are interrelated processes and since bone is constantly being remodelled, the balance between formation and resorption and the endocrine mechanisms which mobilize and regulate calcium is finely tuned.…”