Looker Anne C, Mussolino Michael E
National Center for Health Statistics, Centers for Disease Control and Prevention, Hyattsville, Maryland, USA.
J Bone Miner Res. 2008 Jan;23(1):143-50. doi: 10.1359/jbmr.071003.
We used serum 25(OH)D data from NHANES III and incident hip fracture cases identified using linked mortality and Medicare records, and found that serum 25(OH)D was significantly related to reduced hip fracture risk in non-Hispanic white adults >or=65 yr of age.
The role of vitamin D status in reducing fracture risk is unclear. We examined the relationship between serum 25 hydroxyvitamin D [25(OH)D] and incident hip fracture risk in older non-Hispanic white adults.
The study sample consisted of 1917 white men and women >or=65 yr of age who were examined in the third National Health and Nutrition Examination Survey (NHANES III, 1988-1994), a nationally representative survey. Incident hip fractures were ascertained using linked mortality and Medicare records that were obtained for NHANES III participants. Serum 25(OH)D values were measured with a radioimmunoassay kit. Cox proportional hazards models were used to estimate the relative risk (RR) of hip fracture by serum 25(OH)D level.
There were 156 incident hip fracture cases in the sample. Cases were older, had lower BMD and body mass index, more prevalent spine or wrist fractures and weight loss before baseline, and ate fewer kilocalories and less calcium than noncases. After adjusting for these differences, serum 25(OH)D values exceeding 60 nM were significantly related to hip fracture risk. For example, the multivariate-adjusted RR was 0.64 (95% CI, 0.46-0.89) among individuals with serum 25(OH)D values >or=62.5 nM compared with those with values below this level. When grouped into quartiles, the multivariate-adjusted RR for the second, third, and fourth versus the first quartile of serum 25(OH)D were 0.50 (95% CI, 0.25-1.00), 0.41 (95% CI, 0.24-0.70), and 0.50 (95% CI, 0.29-0.86), respectively.
Serum 25(OH)D was related to a significantly lower hip fracture risk in this cohort of older white adults, even after adjusting for several relevant confounding variables. The relationship did not seem to be linear across all values. Our results support other studies suggesting that serum 25(OH)D values exceeding 60 nM are associated with health benefits.
我们使用了来自美国国家健康与营养检查调查（NHANES III）的血清25(OH)D数据，以及通过关联死亡率和医疗保险记录确定的髋部骨折病例，并发现血清25(OH)D与65岁及以上非西班牙裔白人成年人髋部骨折风险降低显著相关。
维生素D状态在降低骨折风险中的作用尚不清楚。我们研究了血清25羟维生素D[25(OH)D]与老年非西班牙裔白人成年人髋部骨折风险之间的关系。
研究样本包括1917名65岁及以上的白人男性和女性，他们参加了第三次全国健康与营养检查调查（NHANES III，1988 - 1994年），这是一项具有全国代表性的调查。通过为NHANES III参与者获取的关联死亡率和医疗保险记录确定新发髋部骨折病例。使用放射免疫分析试剂盒测量血清25(OH)D值。采用Cox比例风险模型按血清25(OH)D水平估计髋部骨折的相对风险（RR）。
样本中有156例新发髋部骨折病例。病例组年龄更大，并具有更低的骨密度和体重指数，脊柱或腕部骨折更普遍，基线前有体重减轻，且与非病例组相比摄入的千卡热量和钙更少。在对这些差异进行调整后，血清25(OH)D值超过60 nM与髋部骨折风险显著相关。例如，血清25(OH)D值≥62.5 nM的个体与低于该水平的个体相比，多变量调整后的RR为0.64（95%可信区间，0.46 - 0.89）。当分为四分位数时，血清25(OH)D第二、第三和第四四分位数与第一四分位数相比，多变量调整后的RR分别为0.50（95%可信区间，0.25 - 1.00）、0.41（95%可信区间，0.24 - 0.70）和0.50（95%可信区间，0.29 - 0.86）。
在这个老年白人成年人队列中，即使在对几个相关混杂变量进行调整后，血清25(OH)D仍与显著更低的髋部骨折风险相关。这种关系在所有值上似乎并非呈线性。我们的结果支持其他研究，表明血清2(OH)D值超过60 nM对健康有益。
