一个bstract
Bone mineral density assessed using a low-dose chest computed tomography in cystic fibrosis presented a strong correlation with DXA. For CF patients, there is an additional possible benefit of assessing lung and bone health using only one method.http://bit.ly/2vscyrq
致编辑:
Bone mineral density is usually normal in children with a good nutritional status and preserved lung function, and commonly reduced in adolescents and adults with cystic fibrosis [1,,,,2]。然而,一些研究记录了儿童骨矿物质密度低的流行率[3,,,,4], with 28–47% of them with osteopenia and 20–34% with osteoporosis. S塔尔等。[[5] observed that approximately 42% of cystic fibrosis patients present some type of bone fracture up to 25 years.
早期检测到改变的骨矿物质密度对于监测和评估骨骼健康状况很重要。双能X射线吸收法(DXA)目前是测量骨矿物质密度的金标准方法[5]。However, it is considered limited in young individuals with cystic fibrosis [6]。Other methods are used to evaluate bone mineral density, including central and peripheral quantitative computed tomography (QCT), ultrasound, radiography and magnetic resonance imaging [7]。
我n addition, measures such as Hounsfield score (HU), a standardised computed tomography (CT) attenuation coefficient, can provide information necessary for the diagnosis of bone mineral density reduction, with no additional patient costs and no extra radiation exposure in examinations obtained for clinical purposes [8,,,,9]。Schreiber等。[[9] in a cross-sectional study of adults found a significant correlation between Hounsfield score and bone mineral density (r=0.44; p<0.0001). However, we could not find previous studies using chest CT to assess bone mineral density in patients with cystic fibrosis. Considering the elevated number of examinations and tests that cystic fibrosis patients undergo, the benefit of assessing lung and bone health using one test may be even higher.
这项研究的目的是确定患有囊性纤维化的儿童和青少年在腰椎胸椎和DXA的Hounsfield评分之间的相关性。
This was a retrospective cross-sectional study. All cystic fibrosis patients aged between 8 and 19 years, with chest CT and DXA scans, assisted in the outpatient cystic fibrosis clinic of Hospital São Lucas, were included.
根据囊性纤维化基金会共识报告,确认了囊性纤维化患者的诊断[10]。从其电子记录中收集了受试者的人口统计学,诊所和营养数据。我们收集了有关遗传突变,细菌定植和肺功能的数据。计算按年龄和身高按年龄计算的体重指数(BMI)得分,并根据世界卫生组织进行分类[11,,,,12]。
通过胸腔CT(通过Hounsfield评分测量)和腰椎DXA评估骨矿物质密度(通过G·CM测量-2)。使用扫描仪CT 16多层(Lightspeed VCT; GE Healthcare,Milwaukee,WI,美国)进行胸腔CT。13]。我们使用放置在椎骨中心的感兴趣区域中的三个连续胸椎(T10,T11,T12)测量了Hounsfield评分,避免了皮质骨,大血管和病变。平均Hounsfield得分通过三个度量的总和计算出来。在检查前指示所有患者以保持正常的呼吸。DXA扫描是在Hologic Discovery Wi光密度计(Hologic Inc.,美国马萨诸塞州沃尔瑟姆)上进行的。来自DXA扫描的信息,包括Z分数和骨矿物质密度(以G·CM进行测量-2),获得第一到第四腰椎[14]。骨矿物质密度由强度分类rnational Society for Clinical Densitometry, considering z-score ≤2 as low bone mineral density. These examinations are performed routinely (in annual check-up) in patients with cystic fibrosis, at ages between 8 and 19 years.
所有统计分析均使用SPSS(版本17.0; IBM Corporation,Armonk,NY,USA)进行。连续变量表示为平均值±sd或非对称分布的中位数(四分位间范围)。分类变量表示为频率和百分比。计算了皮尔逊的相关系数,以评估胸CT和DXA测量的骨矿物质密度之间的关联。p值<0.05被认为是显着的。该研究得到了巴西Pontifícia大学Católicado Rio Grande do Sul的伦理委员会的批准(CAAE:49692115.7.0000.5336)。
一个total of 18 children and adolescents, with mean age 16.1±3.4 years, were evaluated. There was a predominance of males (66.7%) and 15 (83.3%) participants were Caucasians. Three (16.7%) patients were homozygous for F508del, while nine (50%) were heterozygous for F508del; the remaining six (33.3%) patients carry other CFTR mutations.铜绿假单胞菌was found in six (33.3%) patients. Mean forced expiratory volume in 1 s was 73.6±32.5% pred. The median BMI z-score was 0.03 (−0.88 to 0.81) and 15 (83.4%) patients were classified as normal weight.
The median of bone mineral density z-score by DXA was 0.65 (−1.60 to 0.20) and the mean of thoracic CT was 229.2±30.6 HU. 15 (83.3%) patients were diagnosed as normal and three (16.7%), as low bone mineral density.
通过胸CT和DXA测量的骨矿物密度之间观察到很强的正相关(r = 0.740; p <0.001)(P <0.001)(图1)。
we found a strong positive correlation between bone mineral density measured by thoracic CT and DXA in children and adolescent with cystic fibrosis. In addition, our study results may provide additional early information on bone disease in cystic fibrosis patients.
胸部CT经常用于评估囊性纤维化肺部疾病的进展。从CT扫描获得的Hounsfield评分以评估骨矿物质密度,用S描述chreiber等。[[9] 25例平均年龄71.3岁的患者。结果表明,Hounsfield评分与DXA之间存在显着相关性,他们得出结论,CT数据可能对诊断骨质疏松症很有用。
many studies have evaluated bone mineral density by DXA or peripheral QCT [6,,,,15,,,,16]。However, these methods result in an additional cost. According to international guidelines, DXA scan should first be performed from about 8 to 10 years [2]。我t is a bidimensional method that does not differentiate the cortical and trabecular bone. In addition, peripheral QCT is not widely available, technically demanding and, consequently, it not commonly used in clinical practice.
This study has some methodological limitations like a small sample size, retrospective cross-sectional design, single reference centre and DXA as reference standard. The fact that only three subjects had low bone mineral density is a further limitation. In addition, there is no paediatric reference database to determine z-scores when evaluating bone mineral density by CT of the thoracic vertebrae. Establishing normative data would be a critical step in developing the utility of chest CT to screen for decreased bone density in children. In spite of these concerns, this is the first study to evaluate the correlation between Hounsfield score and DXA in children with cystic fibrosis. Bone health status measured by thoracic CT provides many advantages, such as differentiating the cortical and trabecular bone; it is also possible to evaluate fractures and their complications. It is a simple method and widely used by radiologists, performed without additional cost and in a clinical setting. For cystic fibrosis patients, there is the additional possible benefit of assessing lung and bone health using only one method.
我n conclusion, the present study showed a strong positive correlation between thoracic CT and lumbar DXA to evaluate bone health in children and adolescents with cystic fibrosis, suggesting the possibility of early diagnosis, and thereby enabling the development of new strategies to prevent and treat bone disease. Further studies with larger sample sizes are necessary to confirm the usefulness of chest CT to assess bone health in cystic fibrosis patients.
Footnotes
Conflict of interest: R.G. Feijó Andrade has nothing to disclose.
Conflict of interest: G.C. Forte has nothing to disclose.
Conflict of interest: B. Hochhegger has nothing to disclose.
Conflict of interest: L.A. Pinto has nothing to disclose.
Support statement: Fundação de Amparo à Pesquisa do Rio Grande do Sul (FAPERGS), the National Research Council of Brazil (CNPq) and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior CAPES.
- 已收到January 11, 2019.
- 公认march 13, 2019.
- 版权所有©ERS 2019