Donovan D S, Papadopoulos A, Staron R B, Addesso V, Schulman L, McGregor C, Cosman F, Lindsay R L, Shane E
Departments of Medicine and Radiology, College of Physicians and Surgeons, Columbia University, New York, USA.
Am J Respir Crit Care Med. 1998 Jun;157(6 Pt 1):1892-9. doi: 10.1164/ajrccm.157.6.9712089.
Osteoporosis and fractures are increasingly recognized in children and adults with cystic fibrosis. To investigate the prevalence and pathogenesis of osteoporosis and low bone mass in adults with advanced pulmonary disease due to cystic fibrosis, we examined the relationships between bone mineral density (BMD), anthropomorphic variables, pulmonary status, glucocorticoid therapy, and vitamin D concentrations. BMD of the lumbar spine, hip, and proximal radius was measured by dual energy X-ray absorptiometry in 30 white adults (16 women), age 30 +/- 2 yr (mean +/- SEM). Compared with a normal control population, the patients had significantly reduced BMD at the lumbar spine (17 +/- 3%), total hip and femoral neck (24 +/- 3% and 20 +/- 4%, respectively). The radius was significantly less demineralized (4 +/- 2%; p <= 0.003) than the other sites. Moreover, only 21% of patients with cystic fibrosis had normal BMD (T score > -1.0) at the lumbar spine, 23% at the hip sites, and 39% at the radius. Age, weight, and body mass index (BMI) were most strongly correlated with bone mass, whereas glucocorticoid therapy and pulmonary function were not predictive. Despite oral vitamin D (400 to 800 IU daily), the mean serum 25-hydroxyvitamin D (25-OHD) concentration was at the low end of the normal range (16 +/- 2 ng/ml; normal 10 to 52 ng/ml); 8 of 20 patients (40%) had frankly low (<= 10 ng/ml) levels. BMD was significantly lower in patients with low 25-OHD concentrations at the lumbar spine (0.774 +/- 0.02 versus 0.913 +/- 0.04 g/cm2; p = 0.01) and total hip (0.648 +/- 0.04 versus 0.811 +/- 0.04 g/cm2; p = 0.01). Vertebral fractures were present in 19% of subjects and 41% had a confirmed history of previous fracture. In summary, osteoporosis, low bone mass, and fractures are common in adults with advanced cystic fibrosis lung disease. Despite oral supplements, vitamin D deficiency is also common and is associated with more severe demineralization at the lumbar spine and hip. We conclude that the widespread practice of oral supplementation with 400 to 800 units of vitamin D is ineffective in maintaining normal vitamin D stores in many patients with cystic fibrosis. To ensure adequacy of vitamin D stores, measurement of serum 25-OHD should be included in the routine management of patients with cystic fibrosis.
骨质疏松症和骨折在患有囊性纤维化的儿童和成人中越来越受到关注。为了研究患有晚期囊性纤维化所致肺部疾病的成人骨质疏松症和低骨量的患病率及发病机制，我们检测了骨矿物质密度（BMD）、人体测量学变量、肺部状况、糖皮质激素治疗及维生素D浓度之间的关系。采用双能X线吸收法测量了30名白人成人（16名女性）的腰椎、髋部和桡骨近端的BMD，年龄为30±2岁（均值±标准误）。与正常对照人群相比，患者的腰椎BMD显著降低（17±3%），全髋和股骨颈分别降低24±3%和20±4%。桡骨的脱矿程度明显低于其他部位（4±2%；p≤0.003）。此外，仅21%的囊性纤维化患者腰椎BMD正常（T值＞-1.0），髋部为23%，桡骨为39%。年龄、体重和体重指数（BMI）与骨量的相关性最强，而糖皮质激素治疗和肺功能无预测价值。尽管每日口服维生素D（400至800 IU），但血清25-羟维生素D（25-OHD）的平均浓度仍处于正常范围的下限（16±2 ng/ml；正常范围为10至52 ng/ml）；20名患者中有8名（40%）的水平明显偏低（≤10 ng/ml）。25-OHD浓度低的患者腰椎（0.774±0.02对0.913±0.04 g/cm²；p = 0.01）和全髋（0.648±0.04对0.811±0.04 g/cm²；p = 0.01）的BMD显著更低。19%的受试者存在椎体骨折，41%有既往骨折确诊史。总之，骨质疏松症、低骨量和骨折在患有晚期囊性纤维化肺病的成人中很常见。尽管口服补充维生素D，但维生素D缺乏也很常见，且与腰椎和髋部更严重的脱矿有关。我们得出结论，对许多囊性纤维化患者而言，每日口服补充400至800单位维生素D的普遍做法在维持正常维生素D储备方面无效。为确保维生素D储备充足，在囊性纤维化患者的常规管理中应包括检测血清25-OHD。
