BONE LOSS WITH AGE--EPIDEMIOLOGY, FAMILIAL AND CROSS-CULTURAL CONSIDERATIONS

成人骨丢失是一种普遍现象，并可能导致骨折 和骨质疏松症。 该项目调查了流行病学，遗传学， 骨丢失的横截面，纵向和跨文化方面， BLSA的参与者，以及来自欧洲，日本， 大洋洲、中美洲和非洲。作为我们持续研究的一部分 在BLSA人群中，我们研究了 股骨颈骨矿物质密度（femBMD）， 能量X射线吸收法（DEXA），吸烟391 白人男性和404名白人女性，年龄在21-93岁之间， 分类为当前吸烟者、既往吸烟者和从不吸烟者（吸烟者曾吸烟 2年或以上）。在调整了男性的年龄，体重，身高之后， 目前和以前吸烟者的股骨BMD显著低于从未吸烟者 吸烟者（0.92 ± 02 g/cm 2，0.95 ± 01 g/cm 2， 0.98 ± 0.01g/cm ~ 2，p <0.05），但在 女性（调整雌激素状态）。多年来，吸烟 戒烟多年后，男性的影响会增加，但对女性则不然。 将进一步探讨这种性别差异的原因， 由于暴露的差异。我们还研究了体重的影响 和肥胖对负重时骨密度的影响， 18-96岁的高加索男性和女性的非承重骨骼。在 桡骨，年龄单独解释了女性BMD变异的49%（n=494）， 男性为19%（n=974）。体重可以解释5-6%的差异， 性别，但并没有改善年龄模型。身高一项就能解释20%的 女性和男性的差异为10%;身高和年龄解释了52%的 女性桡骨骨密度的变化，男性为22%。在股骨颈， 年龄单独解释女性BMD变异的36%（n=454）， 男性（n=393）。 仅体重就能解释11%的性别差异; 年龄和体重解释了女性42%和男性22%的变异。高度 单独解释女性股骨颈BMD变异的3%， 男性，但不改善年龄或年龄和体重模型。肥胖、 通过身体脂肪百分比（从皮肤褶皱估计）和腰臀测量 比值不是两个部位BMD的独立预测因子。年龄和 身高可以预测桡骨的BMD，而年龄和体重可以解释桡骨的大部分BMD。 髋部骨密度的变化。

Adult bone loss is a universal phenomenon, and may lead to bone fracture and osteoporosis. This project investigates the epidemiological, genetic, cross-sectional, longitudinal and cross-cultural aspects of bone loss among participants of the BLSA, and among genetic isolates from Europe, Japan, Australasia, Central America and Africa. As part of our ongoing studies of bone status in the BLSA population, we examined the association between femoral neck bone mineral density (femBMD) measured by dual energy x-ray absorptiometry (DEXA), and cigarette smoking in 391 Caucasian men and 404 Caucasian women aged 21-93 years, who were categorized as current, former, and never smokers (smokers had smoked for 2 or more years). After adjustment for age, weight, height, in men, current and former smokers have significantly lower femBMD than never smokers (0.92plus\minus.02 g/cm2, 0.95plus\minus.01 g/cm2 vs. 0.98plus\minus.01g/cm2, p lesser than 0.05), but this is not found in women (with adjustment for estrogen status). Controlling for years smoked and years since quitting increases the effect in men, but not in women. Reasons for this gender difference will be pursued further, and may be due to differences in exposure. We also examined the effects of weight and obesity on bone mineral density (BMD) in weightbearing and non-weightbearing bones in Caucasian men and women aged 18-96. At the radius, age alone explains 49% of the variance in BMD in women (n=494), and 19% in men (n=974). Weight explains 5-6% of the variance in both sexes, but does not improve the age model. Height alone explains 20% of variance in women and 10% in men; height and age explain 52% of the variance in radial BMD in women, and 22% in men. At the femoral neck, age alone explains 36% of the variance in BMD in women (n=454), and 15% in men (n=393). Weight alone explains 11% of the variance in both sexes; age and weight explain 42% of variance in women and 22% in men. Height alone explains 3% of variance in femoral neck BMD in women, and 6% in men, but does not improve the age or age and weight models. Obesity, measured by percent body fat (estimated from skinfolds) and waist-hip ratio are not independent predictors of BMD at either site. Age and stature predict BMD at the radius, while age and weight explain most of the variance in BMD at the hip.