JCEM：低维生素D状态是髋部骨折的危险因素

尽管循环25–羟维生素D与髋部骨折风险之间的关系相当重要，但到目前为止仍没有被充分确立。为了研究挪威，一个处在世界范围内最高髋部骨折发生率中的高纬度国家，血清25–羟维生素D浓度（s–25(OH)D）与髋部骨折风险之间的关系，来自挪威卑尔根大学的Kristin Holvik教授及其团队进行了一项研究，该研究发现血清25–羟维生素D的最低四分位数与最高四分位数相比，受试者的髋部骨折风险增加。与先前以社区为基础的研究结果相一致，低维生素D状态是髋部骨折的中度危险因素。该研究结果在线发表在2013年5月15日的美国《临床内分泌代谢杂志》（The journal of clinical endocrinology & metabolism）上。

该研究中，入选1994–2001年期间，四个以社区为基础的健康研究中的21774例年龄65–79岁的男性和女性受试者。在最高随访10.7年期间，通过电子出院登记获取受试者继发髋部骨折的信息。使用分层病例队列设计，在髋部骨折病例（1175例；男性307例，女性868例）和性别分层随机抽样（1438例）储存血清标本中，通过HPLC–APCI–MS确定s–25(OH)D。进行适合病例队列设计的COX比例风险回归分析。

该研究结果表明，该研究观察到s–25(OH)D与髋部骨折呈负相关；在调整年龄、性别、研究中心和体重指数（BMI）的模型中，s–25(OH)D位于最低四分位数（＜42.2nmol/l）的受试者与最高四分位数（≥67.9nmol/l）的受试者相比，髋部骨折风险增加38%（95%CI 9–74%）。这种相关性在男性强于女性：HR 1.65（95%CI 1.04–2.61）对HR 1.25（95%CI 0.95-1.65）。

该研究发现，在这项迄今为止最大的髋部骨折前瞻性病例队列研究中，发现血清25–羟维生素D的最低四分位数与最高四分位数相比，受试者的髋部骨折风险增加。与先前以社区为基础的研究结果相一致，低维生素D状态是髋部骨折的中度危险因素。

Low serum levels of 25-hydroxyvitamin D predict hip fracture in the elderly. A NOREPOS study.
Abstract
Background:Despite considerable interest, the relationship between circulating 25-hydroxyvitamin D and risk of hip fracture is not fully established.Objective:To study the association between serum 25-hydroxyvitamin D concentrations (s-25(OH)D) and risk of hip fracture in Norway, a high-latitude country that has among the highest hip fracture rates worldwide.Methods:N=21,774 men and women aged 65-79 attended four community-based health studies during 1994-2001. Information on subsequent hip fractures were retrieved from electronic hospital discharge registers, with maximum follow-up 10.7 years. Using a stratified case-cohort design, s-25(OH)D was determined by HPLC-APCI-MS in stored serum samples in hip fracture cases (n=1175; 307 men, 868 women) and in gender-stratified random samples (n=1438). Cox proportional hazards regression adapted for the case-cohort design was performed.Results:We observed an inverse association between s-25(OH)D and hip fracture; those with s-25(OH)D in the lowest quartile (<42.2 nmol/l) had a 38% (95% CI 9-74%) increased risk of hip fracture compared with the highest quartile (>=67.9 nmol/l) in a model accounting for age, gender, study center, and BMI. The association was stronger in men than in women: HR 1.65 (95% CI 1.04-2.61) versus HR 1.25 (95% CI 0.95-1.65).Conclusion:In this prospective case-cohort study of hip fractures, the largest ever reported, we found an increased risk of hip fracture in subjects in the lowest compared to the highest quartile of serum 25-hydroxyvitamin D. In accordance with findings of previous community-based studies, low vitamin D status was a modest risk factor for hip fracture.