Brookes Denise S K, Briody Julie N, Munns Craig F, Davies Peter S W, Hill Rebecca J
The University of Queensland, Queensland Children's Medical Research Institute, Children's Nutrition Research Centre, Brisbane, Australia; The University of Queensland, School of Medicine, Brisbane, Australia.
The Children's Hospital at Westmead, Sydney, Australia.
J Cyst Fibros. 2015 Sep;14(5):668-77. doi: 10.1016/j.jcf.2015.04.005. Epub 2015 May 6.
The investigation of skeletal health data beyond dual X-ray absorptiometry (DXA) is limited in young individuals with CF. We assessed volumetric bone mineral densities (BMD), and bone and muscle parameters using peripheral quantitative computed tomography (pQCT) in individuals with CF and controls, 7.00-17.99 years.
Peripheral QCT (XCT 3000, Stratec) measurements were made in 53 individuals with CF and 53 controls. Bone mineral content (BMC), total volumetric BMD (vBMD) and cross sectional area (CSA) of the bone were measured at the 4% and 66% sites of the non-dominant tibia and radius. Additionally, trabecular vBMD and bone strength index (BSIc) were measured at the 4% sites, and cortical vBMD, muscle CSA (mCSA) and strength strain index (SSI) were measured at the 66% sites.
Pre-pubertal males with CF had greater trabecular vBMD (p=0.01) and total vBMD (p=0.00) at 4% tibia, and greater total vBMD (p=0.02) at 4% radius. Pre-pubertal females with CF had greater total vBMD at 66% tibia (p=0.02) and radius (p=0.04), and cortical vBMD (p=0.04) at the radius. At puberty, the CF cohort had less BMC at 4% tibia (males, p=0.02; females, p=0.01), and smaller mCSA at 66% tibia (males, p=0.02; females, p=0.01). Pubertal CF females had a smaller bone CSA (p=0.01) at 4% tibia, and lower bone strength (SSI) at the tibia (p=0.00) and radius (p=0.05) sites.
Bone strength parameters were not compromised prior to puberty in this CF cohort. At puberty, the bone phenotype changed for this CF cohort, showing several deficits compared to the controls. However, bone strength was adapting to the mechanical demands of the muscle. Altered bone parameters and their implications for lowered bone strength with increased age may be greatly influenced by: the CF cohort remaining smaller for age and/or a reduced bone strain, secondary to reduced muscle force.
在患有囊性纤维化（CF）的年轻个体中，对双能X线吸收测定法（DXA）之外的骨骼健康数据的研究有限。我们使用外周定量计算机断层扫描（pQCT）评估了7.00至17.99岁的CF患者和对照组的体积骨密度（BMD）以及骨骼和肌肉参数。
对53名CF患者和53名对照进行外周QCT（XCT 3000，Stratec）测量。在非优势胫骨和桡骨的4%和66%部位测量骨矿物质含量（BMC）、总体积BMD（vBMD）和骨横截面积（CSA）。此外，在4%部位测量小梁vBMD和骨强度指数（BSIc），在66%部位测量皮质vBMD、肌肉CSA（mCSA）和强度应变指数（SSI）。
青春期前的CF男性在胫骨4%处的小梁vBMD（p = 0.01）和总体积vBMD（p = 0.00）更高，在桡骨4%处的总体积vBMD（p = 0.02）更高。青春期前的CF女性在胫骨66%处（p = 0.02）和桡骨（p = 0.04）的总体积vBMD更高，在桡骨处的皮质vBMD（p = 0.04）更高。在青春期，CF队列在胫骨4%处的BMC较低（男性，p = 0.02；女性，p = 0.01），在胫骨66%处的mCSA较小（男性，p = 0.02；女性，p = 0.01）。青春期的CF女性在胫骨4%处的骨CSA较小（p = 0.01），在胫骨（p = 0.00）和桡骨（p = 0.05）部位的骨强度（SSI）较低。
在该CF队列中，青春期前骨强度参数未受损。在青春期，该CF队列的骨表型发生了变化，与对照组相比显示出一些缺陷。然而，骨强度正在适应肌肉的机械需求。骨参数的改变及其对随着年龄增长骨强度降低的影响可能受到以下因素的极大影响：CF队列年龄较小和/或由于肌肉力量降低导致骨应变减少。
