Han Z H, Palnitkar S, Rao D S, Nelson D, Parfitt A M
Bone & Mineral Division, Henry Ford Hospital, Detroit, Michigan, USA.
J Bone Miner Res. 1997 Apr;12(4):498-508. doi: 10.1359/jbmr.1997.12.4.498.
We measured histologic indices of bone remodeling and turnover separately on the cancellous, endocortical, and intracortical subdivisions of the endosteal envelope, and on the combined total surface, in transiliac bone biopsies obtained after double tetracycline labeling in 142 healthy women, aged 20-74 years, 34 black and 108 white, 61 premenopausal and 81 postmenopausal. The data were analyzed by two-way analysis of variance of the four groups defined by age/menopause and ethnicity and by linear regression of the major variables on age. None of the interaction terms was significant and none of the regression slopes on age differed between blacks and whites, indicating that, as for the previously reported structural indices, the effects of ethnicity and of age/menopause are independent. Accordingly, the data were also analyzed separately for the effect of ethnicity (pre- and postmenopausal combined) and age/menopause (blacks and whites combined). The analyses led to the following conclusions. (1) The geometric mean bone formation rate on the combined total surface was 25% lower in blacks than in whites; other histologic differences between ethnic groups were inconsistent between surfaces. (2) Serum osteocalcin (OC) but not bone-specific alkaline phosphatase (BSAP) was lower by about 15% in blacks than in whites. (3) The lower bone turnover in blacks is most likely in the directed rather than in the stochastic component because of a higher bone mass and consequent reduced susceptibility to fatigue damage. (4) All Class 1 bone formation variables and the three resorption indices were significantly higher in the postmenopausal compared with the premenopausal subjects, reflecting a 33% increase in activation frequency. (5) BSAP, but not OC, was increased relatively more (66%) than the bone formation rate (BFR). Consequently, BSAP is more sensitive to the effects of menopause than OC, but OC is more sensitive to the effects of ethnicity than BSAP. (6) There were highly significant differences between the three subdivisions of the endosteal envelope for every non-cell-related variable. All Class 1 formation variables were highest on the endocortical surface, but the magnitude and pattern of the differences otherwise was inconsistent between variables. The contributions of the different subdivisions to the total bone formation rate were cancellous 54%, endocortical 13%, and intracortical 33%. (7) The previously reported changes in bone surface location, together with the presently reported changes in activation frequency and wall thickness indicated that there was no significant effect of age/menopause on erosion depth on the cancellous and intracortical surfaces but a large increase in erosion depth on the endocortical surface. (8) The increase in bone turnover that results from hormonal changes is most likely in the stochastic rather than in the directed component because it serves no purpose but has harmful effects on skeletal integrity.
我们在142名年龄在20 - 74岁之间的健康女性（34名黑人、108名白人，61名绝经前、81名绝经后）的双侧四环素标记后的髂骨活检标本中，分别测量了骨内膜包膜的松质骨、骨内膜皮质内表面、皮质内表面以及整个总表面的骨重塑和骨转换的组织学指标。通过年龄/绝经状态和种族定义的四组的双向方差分析以及主要变量与年龄的线性回归对数据进行分析。没有一个交互项具有显著性，黑人和白人在年龄上的回归斜率没有差异，这表明，就像之前报道的结构指标一样，种族和年龄/绝经状态的影响是相互独立的。因此，我们还分别分析了种族（绝经前和绝经后合并）和年龄/绝经状态（黑人和白人合并）的影响。分析得出以下结论：（1）黑人在整个总表面上的几何平均骨形成率比白人低25%；种族之间的其他组织学差异在不同表面上并不一致。（2）黑人的血清骨钙素（OC）比白人低约15%，但骨特异性碱性磷酸酶（BSAP）没有差异。（3）黑人较低的骨转换很可能是在定向成分而非随机成分中，因为骨量较高，因此对疲劳损伤的易感性降低。（4）与绝经前受试者相比，绝经后受试者所有1类骨形成变量和三个吸收指标均显著更高，反映出激活频率增加了33%。（5）BSAP相对骨形成率（BFR）的增加幅度更大（66%），而OC没有。因此，BSAP对绝经的影响比OC更敏感，但OC对种族的影响比BSAP更敏感。（6）对于每个非细胞相关变量，骨内膜包膜的三个亚部位之间存在高度显著差异。所有1类形成变量在骨内膜皮质内表面最高，但除此之外，变量之间差异的大小和模式并不一致。不同亚部位对总骨形成率的贡献分别为：松质骨54%、骨内膜皮质内表面13%、皮质内表面33%。（7）之前报道的骨表面位置变化，以及目前报道的激活频率和壁厚度变化表明，年龄/绝经状态对松质骨和皮质内表面的侵蚀深度没有显著影响，但骨内膜皮质内表面的侵蚀深度大幅增加。（8）激素变化导致的骨转换增加很可能是在随机成分而非定向成分中，因为它没有任何作用，反而对骨骼完整性有有害影响。
