Gallacher S J, McQuillian C, Harkness M, Finlay F, Gallagher A P, Dixon T
Medical Unit, Southern General Hospital, Glasgow, Scotland, UK.
Curr Med Res Opin. 2005 Sep;21(9):1355-61. doi: 10.1185/030079905X59148.
It is well established that vitamin D levels are sub-optimal in the elderly and that adults with fragility fracture are more likely to have serum vitamin D levels either lower than those of control patients of similar age, or below the normal range.
To investigate the prevalence of vitamin D inadequacy in an elderly population presenting to the South Glasgow Fracture Liaison Service with non-vertebral fragility fractures in order to assess the extent of the problem.
The retrospective arm of this study used data from an established database to identify patients aged over 50 years admitted to South Glasgow University Hospitals over the previous 4 years with hip fracture. The prospective arm identified the first 50 patients aged over 50 presenting with a clinical non-vertebral fragility fracture with osteoporosis as measured by axial spine and/or hip DEXA (T-score < -2.5) after November 2004.
In the retrospective arm, 626 patients were identified from the database: mean age 80.5 years; 94% were aged over 60 and 74% were aged over 75. Data analysis was limited to 548 patients aged over 60 years with vitamin D recordings and not receiving supplementation with calcium and vitamin D. The mean vitamin D level was 24.7 nmol/L (9.9 ng/ml) SD = 17, however, it is likely that the true mean is lower since in approximately 25% of cases vitamin D levels were reported as < 15 nmol/L (effectively unrecordable). These were transcribed as 15 nmol/L in order to permit a numerical value to be calculated. In the absence of an agreement on what should constitute a diagnostic serum level of vitamin D inadequacy, a number of thresholds were considered--97.8% had vitamin D levels below 70 nmol/L and 91.6% had vitamin D levels below 50 nmol/L. There were no significant differences by patient sex, age or season of presentation. The mean age of patients in the prospective arm was 65.8 years (range 50.6-83.8), 72% were aged over 60 and 16% were aged over 75. The mean vitamin D level was 44.1 nmol/L (18.4 ng/ml) SD = 25.3; 82% had vitamin D levels below 70 nmol/L and 72% had vitamin D levels below 50 nmol/L. Although numbers were too small to justify extensive subgroup analyses, the mean vitamin D level in the 13 patients with hip fracture (34.5 nmol/L) was lower than in the 37 with non-hip fractures (48.2 nmol/L).
This study confirms almost universal vitamin D inadequacy among 548 elderly patients admitted to hospital with hip fracture, regardless of whether a threshold of 50 nmol/L or 70 nmol/L was used. However, among a prospective subset of 50 patients with clinical fragility fractures, especially those with non-hip fractures, the prevalence of inadequacy was substantially lower. It may be that vitamin D represents a correctable risk factor for fragility fracture in the elderly, possibly specifically for the hip.
众所周知，老年人的维生素D水平不理想，而且患有脆性骨折的成年人血清维生素D水平更有可能低于年龄相仿的对照患者，或低于正常范围。
调查就诊于南格拉斯哥骨折联络服务处、患有非椎体脆性骨折的老年人群中维生素D不足的患病率，以评估该问题的严重程度。
本研究的回顾性部分使用了一个已建立数据库中的数据，以识别过去4年里因髋部骨折入住南格拉斯哥大学医院的50岁以上患者。前瞻性部分纳入了2004年11月之后出现临床非椎体脆性骨折且经脊柱和/或髋部双能X线吸收法（T值＜-2.5）测量患有骨质疏松症的首批50例50岁以上患者。
回顾性部分从数据库中识别出626例患者：平均年龄80.5岁；94%的患者年龄超过60岁，74%的患者年龄超过75岁。数据分析仅限于548例年龄超过60岁、有维生素D记录且未补充钙和维生素D的患者。维生素D平均水平为24.7 nmol/L（9.9 ng/ml），标准差=17，然而，实际平均水平可能更低，因为约25%的病例报告维生素D水平＜15 nmol/L（实际上无法记录）。为了能够计算数值，这些数据被记录为15 nmol/L。由于对于维生素D不足的诊断血清水平尚无定论，因此考虑了多个阈值——97.8%的患者维生素D水平低于70 nmol/L，91.6%的患者维生素D水平低于50 nmol/L。患者的性别、年龄或就诊季节之间无显著差异。前瞻性部分患者的平均年龄为65.8岁（范围50.6 - 83.8岁），72%的患者年龄超过60岁，16%的患者年龄超过75岁。维生素D平均水平为44.1 nmol/L（18.4 ng/ml），标准差=25.3；82%的患者维生素D水平低于70 nmol/L，72%的患者维生素D水平低于50 nmol/L。尽管样本数量过少，无法进行广泛的亚组分析，但13例髋部骨折患者的维生素D平均水平（34.5 nmol/L）低于37例非髋部骨折患者（48.2 nmol/L）。
本研究证实，548例因髋部骨折入院的老年患者中几乎普遍存在维生素D不足，无论采用50 nmol/L还是70 nmol/L的阈值。然而，在50例临床脆性骨折患者的前瞻性亚组中，尤其是那些非髋部骨折患者，不足的患病率要低得多。维生素D可能是老年人脆性骨折的一个可纠正风险因素，可能尤其针对髋部骨折。
