Ahlborg Henrik G, Johnell Olof, Turner Charles H, Rannevik Gunnar, Karlsson Magnus K
Department of Orthopedics, Malmö University Hospital, Malmö, Sweden.
N Engl J Med. 2003 Jul 24;349(4):327-34. doi: 10.1056/NEJMoa022464.
Bone loss increases after menopause. However, bone strength also depends on structural characteristics such as bone size. Whether bone size increases as a result of periosteal apposition and whether a strength index accounting for both bone density and bone size might predict the risk of fracture better than bone density alone are unclear.
Bone mass and the skeletal structure of the distal radius were evaluated by single-photon absorptiometry every other year in 108 women, all of whom were followed from the time of menopause for a mean period of 15 years. Postmenopausal serum estradiol levels and fractures of the distal radius were noted.
The mean (+/-SD) annual decrease in bone mineral density was 1.9+/-0.7 percent. The medullary bone diameter increased annually by 1.1+/-0.9 percent, and the periosteal diameter by 0.7+/-0.3 percent; the strength index decreased by 0.7+/-0.7 percent. The expansion of the medullary diameter and the expansion of the periosteal diameter were correlated with one another (r = 0.54, P<0.001), and women in the highest quartile of medullary expansion had more loss of bone mineral density and greater periosteal apposition than women in the lowest quartile (P<0.001 for both comparisons). The postmenopausal serum estradiol level was correlated with changes in the periosteal diameter (r = -0.25, P=0.009) and with changes in bone mineral density (r = 0.34, P<0.001). A 1-SD decrement in the strength index at base line was associated with a risk ratio for fracture of the distal radius of 3.8 (95 percent confidence interval, 1.8 to 8.0).
Increased bone loss after menopause is associated with increased periosteal apposition, which partially preserves bone strength. A strength index may be a helpful predictor of the risk of fracture.
绝经后骨质流失会增加。然而，骨强度还取决于诸如骨大小等结构特征。骨大小是否因骨膜附着而增加，以及一个同时考虑骨密度和骨大小的强度指数是否比单独的骨密度更能预测骨折风险尚不清楚。
对108名女性每隔一年用单光子吸收法评估桡骨远端的骨量和骨骼结构，所有女性均从绝经时开始随访，平均随访期为15年。记录绝经后血清雌二醇水平和桡骨远端骨折情况。
骨矿物质密度平均每年下降（±标准差）1.9±0.7%。髓腔直径每年增加1.1±0.9%，骨膜直径增加0.7±0.3%；强度指数下降0.7±0.7%。髓腔直径的扩大和骨膜直径的扩大相互相关（r = 0.54，P<0.001），髓腔扩大处于最高四分位数的女性比最低四分位数的女性有更多的骨矿物质密度丢失和更大的骨膜附着（两项比较P均<0.001）。绝经后血清雌二醇水平与骨膜直径变化相关（r = -0.25，P = 0.009），与骨矿物质密度变化相关（r = 0.34，P<0.001）。基线时强度指数下降1个标准差与桡骨远端骨折的风险比为3.8相关（95%置信区间，1.8至8.0）。
绝经后骨质流失增加与骨膜附着增加相关，这部分维持了骨强度。强度指数可能有助于预测骨折风险。
