The Long-Term Effect of Menopause on Postmenopausal Bone Loss in Japanese Women: Results from a Prospective Study

Abstract

The aim of this study was to elucidate perimenopausal bone loss in relation to menstrual conditions and to investigate the long-term effect of menopause on bone loss in aged women. The rate of change in bone mineral density (BMD) was measured twice at an exact interval of 12 months by dual-energy X-ray absorptiometry (DXA) at the lumbar spine in 176 pre-and postmenopausal healthy women 41-65 years of age. Serum follicle-stimulating hormone, intact and N-fragment osteocalcin (OC), three types of vitamin D 3 , parathyroid hormone (PTH), and calcitonin were also determined. Women who exercised regularly or had anatomical changes at the lumbar spine were excluded from this study. The subjects were divided into eight groups based on their menstrual status and years since menopause. Annual bone loss at the lumbar spine of premenopausal women with regular menstruation was ؊0.2 ؎ 1.9% (95% confidence interval, ؊0.9ϳ-0.4%) and was not statistically different from zero, while that of women with irregular menstruation or at menopausal transition was ؊2.1 ؎ 3.4% (؊3.4ϳ؊0.8%), and ؊3.3 ؎ 2.3% (؊5.2ϳ؊0.3%), respectively, and was significantly different from zero. Serum OC levels of women at menopausal transition were significantly higher than those of women with regular menstruation, suggesting that bone loss had commenced in these women. The rate of annual change in BMD of women who were menopausal for 1-3, 4 -6, 10 -12, and more than 13 years was ؊3.1 ؎ 4.0% (؊4.7ϳ؊1.5%), ؊1.2 ؎ 2.6% (؊2.2ϳ؊0.2%), ؊1.0 ؎ 3.0% (؊2.3ϳ؊0.3%), and ؊2.3 ؎ 2.1% (؊3.7ϳ؊1.0%), respectively, and was significantly less than zero. But the annual bone loss of women who were menopausal for 7-9 years was ؊1.5 ؎ 2.6% (؊3.0ϳ؊0.1%) and was not statistically significant from zero. These results indicate that postmenopausal women lose BMD in two phases. The early bone loss is rapid and commences during irregular menstruation, then is attenuated within 6 years after the onset of menopause. The second bone loss commences after the attenuation of the first bone loss. Among bone metabolic hormones, intact PTH alone showed an age-related increase and was suggested as being a causal factor of bone loss in women who were menopausal for 13 years or more. (J Bone Miner Res 1998;13:303-309)

Risedronate for the Prevention and Treatment of Postmenopausal Osteoporosis: Results From Recent Clinical Trials

“…The annual rate of bone loss, as a percentage of baseline BMD, was highest in the perimenopausal group (-2.35%), lowest in the premenopausal group (-0.79%) and intermediate in the postmenopausal group (-1.24%). In a more recent study from Japan, a group of women was divided into eight categories, depending on menopausal status [5]. Results were similar to those of the study by Pouilles and colleagues, with evidence of an additional period of accelerated bone loss occurring later in life (13 years or more since menopause) (Fig.…”

“…Estrogen also may promote osteoclast apoptosis, so that estrogen withdrawal results in an increase in osteoclasts [8]. Despite the widespread use of ERT [5].) among postmenopausal women, it is not fully effective for prevention of bone loss, and its use is associated with unpleasant side effects that often make long-term compliance difficult.…”

Relation of lifestyle factors to metacarpal bone mineral density was different depending on menstrual condition and years since menopause in Japanese women

“…Lifestyle and metacarpal bone mineral density K Ishikawa et al lumbar spine BMD loss also reported that the loss commenced during irregular menstruation and was attenuated within 6 y of menopause (Okano et al, 1998). Therefore, it was suggested that early postmenopause corresponds to 4 ± 6 y after menopause.…”

“…However, the results of lifestyle factors affecting BMD were not consistent among the studies. Moreover, some studies suggested the possibility of different effects of calcium intake or exercise on bone mass among different life-stages (Lewis & Modlesky, 1998;Okano et al, 1998). However, there has been no report directly comparing the relation between lifestyle factors and BMD among different life-stages.…”

Comparison of bone mineral densities between postmenopausal women who swam regularly and those who took art classes

“…At 7-9 years after menopause, the degree of decrease in BMD remains gradual 21) , and when compared to immediately after menopause or in old age, the effects of exercise are more likely to appear. This age group is not faced with rapid though no significant intergroup differences were observed, calcium intake was greater in the art group than the swimming group, who displayed an intake of 250 mg/day less than the recommended daily calcium requirement for elderly Japanese (850 mg/day) 22) .…”