高分辨外周骨定量CT评估阻塞性睡眠呼吸暂停患者的骨质情况

High-resolution Peripheral Quantitative Computed Tomography for the Assessment of Bone Strength and Structure in Obstructive Sleep Apnea Patients

目的通过高分辨外周骨定量CT(HR-pQCT)检测阻塞性睡眠呼吸暂停(OSA)患者的骨强度及结构,探索其与骨质疏松症之间的联系。方法连续收入2017年8月至2019年1月于本院睡眠呼吸中心就诊的男性患者,完善相关临床资料,包括爱普沃茨睡眠量表(ESS)评分、整夜多导睡眠监测等,行HR-pQCT测定其非优势侧的肱骨及胫骨的相关指标,比较不同严重程度的OSA患者及非OSA人群在骨几何学参数、骨密度及骨微结构方面的差异,并寻找OSA与骨质疏松症的联系。结果本研究共纳入83名受试者,其中轻、中、重度及不符合OSA的对照组人数分别为21、18、34及10人。4组人群在年龄、血压、ESS评分、睡眠分期及睡眠效率等方面差异均无统计学意义(P>0.05),在体质量指数(BMI)及颈围方面差异有统计学意义(F=4.234,P=0.008;F=3.100,P=0.031)。4组研究对象的桡骨HR-pQCT指标差异均无统计学意义(P>0.05)。在胫骨方面,4组研究对象骨几何参数指标皮质骨面积(Ct.Ar)差异有统计学意义(F=3.937,P=0.011);骨微结构指标骨小梁厚度(Tb.Th)、皮质骨厚度(Ct.Th)差异有统计学意义(F=6.247,P=0.001;F=3.746,P=0.014),表现为3组病例组的均值均低于对照组。进一步两两比较显示,重度OSA组的Ct.Ar明显高于轻度OSA组(P=0.019);对照组的Tb.Th明显高于轻、中度OSA组(P=0.006,P=0.001)。相关性分析显示,在一定范围内,桡骨和胫骨的总体积骨密度(Tt.vBMD)、Tb.Th与年龄呈负相关(r=-0.312,P=0.004;r=-0.328,P=0.002;r=-0.265,P=0.015;r=-0.280,P=0.010;),与BMI呈正相关(r=0.240,P=0.029;r=0.369,P=0.004;r=0.299,P=0.006;r=0.416,P=0.010)。逐步多元回归分析显示,桡骨与胫骨的Tb.Th受BMI(β=0.262,P=0.008,R^2=0.243,F=6.270,P=0.000;β=0.494,P=0.000,R^2=0.186,F=7.243,P=0.000)及年龄(β=-0.216,P=0.030,R^2=0.243,F=6.270,P=0.000;β=-0.306,P=0.003,R^2=0.186,F=7.243,P=0.000)的影响,桡骨Tt.vBMD与睡眠效率及OSA引起的夜间较低的平均血氧饱和度亦具有一定的相关性(β=0.312,P=0.002,β=-0.249,P=0.012,R^2=0.327,F=7.482,P=0.000)。结论本研究表明,在非老年男性中,OSA主要引起胫骨Tb.Th、Ct.Th的下降。骨强度及结构的改变主要与年龄及体型相关,与睡眠效率及OSA引起的夜间平均血氧饱和度的下降亦具有一定的相关性。

Objective To evaluate the bone strength and structure of patients with obstructive sleep apnea(OSA)by the high-resolution peripheral quantitative computed tomography(HR-pQCT)and to explore the relationship between OSA and osteoporosis.Methods Male patients who visited the Sleep Respiratory Center of our hospital from August 2017 to January 2019 were consecutively recruited.Clinical data including the results of Epworth sleep scale(ESS)scoring and overnight polysomnography were collected.HR-pQCT was used to compare the differences in bone geometry,density,and microstructure between OSA patients and non-OSA people;also,the radius and tibia on the non-dominant side were measured to explore the relationship between OSA and osteoporosis.Results A total of 83 subjects were enrolled in the study.The number of patients in the mild,moderate,and severe OSA groups and non-OSA group were 21,18,34,and 10,respectively.There was no significant difference in age,blood pressure,ESS score,sleep stage,and sleep efficiency among these four groups(P>0.05).Body mass index(BMI)and neck circumference were significantly different among these groups(F=4.234,P=0.008;F=3.100,P=0.031).There was no significant difference in the radius indicators(P>0.05).For tibia,there were significant differences among the four groups in the cortical area(Ct.Ar)(F=3.937,P=0.011).There were also significant differences in the bone microstructural indicators including trabecular thickness(Tb.Th)and cortical thickness(Ct.Th)(F=6.247,P=0.001;F=3.746,P=0.014),which were significantly lower in the three OSA groups than in the control group.Pairwise comparisons showed that the Ct.Ar in the severe OSA group was significantly higher than that in the mild OSA group(P=0.019)and Tb.Th in the control group was significantly higher than those in the mild and moderate OSA groups(P=0.006,P=0.001).Correlation analysis showed that,within a certain range,total volumetric bone mineral density(Tt.vBMD)and Tb.Th of radius and tibia were negatively correlated with age(r=-0.312,P=0.004;r=-0.328,P=0.002;r=-0.265,P=0.015;r=-0.280,P=0.010)and positively correlated with BMI(r=0.240,P=0.029;r=0.369,P=0.004;r=0.299,P=0.006;r=0.416,P=0.010).Stepwise multiple regression analysis showed that Tb.Th of radius and tibia were mostly correlated with BMI(β=0.262,P=0.008,R^2=0.243,F=6.270,P=0.000;β=0.494,P=0.000,R^2=0.186,F=7.243,P=0.000)and age(β=-0.216,P=0.030,R^2=0.243,F=6.270,P=0.000;β=-0.306,P=0.003,R^2=0.186,F=7.243,P=0.000).Tt.vBMD of radius had a certain correlation with sleep efficiency and with the decreasing nocturnal mean oxygen saturation caused by OSA(β=0.312,P=0.002,β=-0.249,P=0.012,R^2=0.327,F=7.482,P=0.000).Conclusions In non-elderly male populations,OSA mainly causes a decrease in Tb.Th and Ct.Th of the tibia.The changes in bone strength and structure are mainly related with age and body size and also have certain correlations with sleep efficiency and with the decreasing nocturnal mean oxygen saturation caused by OSA.