慢性阻塞性肺疾病患者骨密度改变及相关因素分析

Changes of bone mineral density of patients with chronic obstructive pulmonary disease and analysis of the related factors

目的通过测定慢性阻塞性肺疾病（COPD）患者骨密度、肺功能、血气分析、血清钙离子、超敏c反应蛋白（hs．CRP）及生活质量的变化，探讨COPD对骨密度的影响。方法采用超声波干式骨密度仪测定32例COPD患者（COPD组）和35例健康体检者（对照组）的骨密度，测量部位为左侧跟骨，骨密度指标包括超声波传递速度（SOS）、SOST、骨折风险系数（OSI）、骨强度（TI）。COPD组根据肺功能分为轻度3例、中度14例和重度15例；根据骨密度分为骨密度正常3例、骨密度减少24例和骨质疏松5例；根据既往有无全身性糖皮质激素应用史，分为既往有全身性糖皮质激素应用史10例和既往无全身性糖皮质激素应用史22例。比较COPD组与对照组的骨密度水平，分析COPD患者的骨密度与肺功能、血气分析、血清钙离子、hs．CRP及生活质量的相关性。结果COPD组与对照组比较，骨密度减低（P〈0．05）。重度COPD患者较中度COPD患者骨密度减低（P〈0．05），重度COPD患者较轻度COPD患者SOS减低（JP〈0．05），SOS、SOST、TI比较差异无统计学意义（P〉0．05），中度COPD患者与轻度COPD患者比较差异无统计学意义（P〉0．05）；骨质疏松COPD患者较骨密度减少COPD患者及骨密度正常COPD患者的动脉血氧分压（PaO2）明显降低，hs．CRP及COPD评估测试（CAT）评分明显升高；骨密度减少COPD患者较骨密度正常COPD患者的PaO2降低，CAT评分升高（P〈0．05）；骨密度正常、骨密度减少及骨质疏松COPD患者之间血清钙离子浓度比较差异无统计学意义（P〉0．05）；既往有全身性糖皮质激素应用史COPD患者较既往无全身性糖皮质激素应用史COPD患者骨密度减低（P〈0．05）。相关性分析表明SOS、SOST、OSI、TI均与第1秒用力呼气容积占预计值的百分比（FEV。％）有相关性（r值分别为O．389、0．262、-0．295、0．265，P值均〈0．05），与PaO2有相关性（r值分别为0．391、0．100、-0．374、0．122，P值均〈0．05），与CAT评分也有相关性（r值分别为-0．659、-0．463、0．175、-0．178，P值均〈0．05），SOS与hs—CRP呈负相关（r=-0．390，P〈0．05）；Logistic回归分析表明PaO2和FEV1％是COPD患者骨密度减低的危险因素。结论COPD患者的骨密度较同龄健康体检者减低，PaO2减低、肺功能差是骨密度减低的危险因素，推测与COPD的慢性炎性反应有关。

Objective To study the relationship between chronic obstructive pulmonary disease （COPD） and osteoporosis by measuring the bone mineral density （BMD）, lung function, blood gas analysis, calcium ion, high sensitive C reactive protein （hs-CRP） and the quality of life. Methods BMD measuring was performed by ultrasound dry bone densitometer in 32 patients with COPD （COPD group） and 35 healthy controls （control group）. The ultrasonic transmission speed （SOS）, SOS T, fracture risk factor （OSI） and bone strength （TI） were measured at the sites of the left calcaneus. COPD group was divided into three groups according to lung function, 3 eases of mild, 14 eases of moderate and 15 cases of severe. According to the level of BMD, there were another three groups, 3 cases with normal BMD, 24 eases with lower BMD, and 5 eases with osteoporosis. According to the history of systemic glueoeorticoid application, COPD group was divided into two groups, 10 cases with glucocorticoid application and 22 cases without glucocortieoid application. The levels of BMD between COPD group and control group were compared, and the correlation between BMD and lung function, blood gas analysis, calcium ion, hs-CRP and the quality of life in patients with COPD was analyzed. Results COPD group had lower BMD than that in control group （P 〈 0.05 ）. In COPD group, the severe patients had lower BMD than the moderate patients （P 〈 0.05 ）, and the severe patients had only lower SOS than the mild patients（P 〈 0.05 ）, but there was no statistic significant difference in BMD between the moderate and mild patients（P 〉 0.05）. According to the level of BMD, the osteoporosis patients had lower arterial oxygen tension （PaO2） and higher hs-CRP and COPD assessment test （CAT） than the normal BMD and lower BMD patients, and the lower BMD patients had lower PaO2 and higher CAT than the normal BMD patients （P 〈 0.05）, but there was no statistic significant difference in calcium ion among them（P 〉 0.05）. According to the history of systemic glucocorticoid application, the patients with glucoeorticoid application had lower level of BMD than the other patients （P 〈 0.05 ）. SOS, SOS T, OSI and TI was correlated with one second forced expiratory volume percent predicted （FEVm%） （r = 0.389, 0.262,-0.295, 0.265; P 〈 0.05 ）, also correlated with PaO2 （r = 0.391, 0.100, -0.374, 0.122 ;P 〈 0.05）, and also correlated with CAT （r =-0.659,-0.463, 0.175,-0.178;P 〈 0.05）. There was only a negative correlation between SOS and hs-CRP （r =-0.390,P 〈 0.05 ）. Further in Logistic regression analysis, the results showed that both PaOz and FEV1% were the risk factors of BMD reduction. Conclusions Patients with COPD have lower BMD than their peers of healthy. The reduction of blood oxygen pressure and lung function are the risk factors of BMD reduction. There is a conjecture that the reduced BMD is correlated with chronic inflammation in patients with COPD.