絕經后女性椎體骨折與髖部骨密度及年齡的相關性研究

曹威　朱秀芬　陳新　林華

?

絕經后女性椎體骨折與髖部骨密度及年齡的相關性研究

曹威朱秀芬陳新林華

目的分析絕經后女性椎體骨折與髖部骨密度、年齡、身高、體質量及體質量指數(BMI)的相關性。方法對2012年1月至2015年6月我院骨質疏松門診就診的絕經后女性患者的臨床資料進行回顧性分析。收集患者年齡、身高、體質量和髖部(全髖、股骨頸)骨密度(BMD)值,并通過胸腰段X線側位片評估椎體形態,計算出反映脊柱椎體骨折總和的脊柱畸形指數(SDI)。對椎體骨折組和無椎體骨折組臨床資料進行分析比較。采用Spearman檢驗,分析SDI與年齡、身高、體質量、BMI及髖部BMD之間的相關性,具有顯著相關性的因素進行線性回歸分析。結果共213例患者入組,骨質疏松性椎體骨折組114例(53.52%),無椎體骨折組99例(46.49%),骨折涉及278個椎體,發生頻率前5位的椎體依次為:L1(51次,18.35%)、T12(48次,17.27%)、T11(45次,16.19%)、L4(29次,10.43%)、T7(28次,10.07%)。根據髖部BMD進行骨量評估,椎體骨折組骨質疏松50例(43.86%),骨量減少63例(56.14%),無椎體骨折組骨質疏松23例(23.23%)。椎體骨折組較無椎體骨折組具有較高的年齡、較低的身高及較低的全髖和股骨頸BMD,差異均有統計學意義(P均<0.001),在體質量及BMI方面2組差異無統計學意義。年齡、身高、BMI及全髖和股骨頸BMD與SDI顯著相關,其r值依次為0.361、-0.334、0.179、-0.409、-0.364,P均<0.001。進一步行線性回歸分析,各因素對SDI影響程度大小依次為全髖BMD、身高、股骨頸BMD、年齡及BMI。結論骨量丟失、增齡是絕經后女性骨質疏松性椎體壓縮性骨折發生的危險因素。

骨質疏松骨折; 椎體骨折; 髖部骨密度; 脊柱畸形指數

骨質疏松骨折又稱脆性骨折,以絕經后女性及老年人群為主要發生對象。椎體骨折在絕經后女性中發病率約為30%,居各類骨質疏松骨折之首,常可帶來急慢性疼痛、脊柱畸形、活動能力下降、生活質量下降甚至殘疾和死亡,且這些影響與骨折的類型及嚴重程度密切相關[1-2]。Genant等[3-4]提出半定量法以評估單椎體骨折程度,并據此提出反映脊柱椎體骨折程度總和的脊柱畸形指數(spinal deformity index,SDI),目前此法已成為臨床評估椎體骨折最常用的方法。Tsang等[5]研究表明,SDI結合骨密度(bone mineral density,BMD)及椎體骨折相關危險因素可顯著提高老年人群椎體骨折的預測水平及檢出率。本文以絕經后女性為研究對象,探討SDI與髖部BMD、年齡、身高、體質量及BMI等因素的關聯性,從而為骨質疏松性椎體壓縮性骨折(osteoporotic vertebral compression fractures,OVCF)的預測評估提供一些指征。

1　對象與方法

1.1研究對象2012年1月至2015年6月我院骨質疏松門診初次就診的絕經后女性患者213例,年齡45～89歲,平均(67.56±9.25)歲。入選標準:主訴均以“腰背痛”為主要內容,并初次接受雙能X線BMD檢查,無骨質疏松治療既往史。排除標準:對骨代謝有明顯影響的相關疾病(原發性甲狀旁腺功能亢進癥、庫欣綜合征、甲狀腺疾病、類風濕關節炎、強直性脊柱炎、嚴重神經呼吸及肝腎系統疾病等)和相關藥物(糖皮質激素、精神類藥物、抗凝血藥物等)應用史等。所有患者均簽署知情同意書。

1.2研究方法

1.2.1基本信息收集:包括出生日期、身高、體質量,并計算體質量指數(BMI)。

1.2.2骨密度測定:應用雙能X線骨密度測量儀(iDXA,GE,USA)進行全髖及股骨頸BMD的測定。

1.2.3椎體形態評估:應用椎體X線成像獲得胸腰段側位片,通過對椎體的視覺觀察,將T4至L4椎體的形態變化分為正常(0度)、輕度(1度)、中度(2度) 和重度(3度) 骨折。1度椎體骨折相當于椎體前、中或后部的高度降低約20%～25%或面積減少約10%～20%;2度椎體骨折相當于上述3部位椎體高度降低約26%～40%或面積減少約21%～40%;3度椎體骨折相當于上述3部位椎體高度降低>40%或面積減少>40%。依據椎體形態分度,將每一個椎體賦予不同的分值,即0分(正常)、1分(輕度骨折)、2分(中度骨折)和3分(重度骨折),最終將T4至L4 13個椎體的分值相加得出SDI值。

1.3統計學方法利用Excel軟件進行資料的數據管理,采用SPSS 18.0軟件進行統計學分析。計量數據用均數±標準差表示,2組數據均符合正態分布且方差齊采用成組t檢驗。采用Spearman檢驗分析SDI和年齡、身高、體質量、BMI及髖部BMD之間的關聯性,具有顯著相關的因素進入線性回歸分析,P<0.05表示差異有統計學意義。

2　結果

2.1患者臨床基本信息符合條件患者共計213例,其中椎體骨折114例(53.52%),無椎體骨折99例(46.49%),骨折涉及278個椎體,骨折頻率前5位的椎體為:L1(51次,18.35%)、T12(48次,17.27%)、T11(45次,16.19%)、L4(29次,10.43%)、T7(28次,10.07%)。依據髖部BMD進行骨量評估,椎體骨折組骨質疏松50例(43.86%),骨量減少63例(56.14%),無椎體骨折組骨質疏松23例(23.23%),骨量減少56例(56.57%)。其中椎體骨折組較非椎體骨折組具有較高的年齡、較低的身高及較低的全髖和股骨頸BMD,差異具有統計學意義(P均<0.001),2組在體質量及BMI方面差異無統計學意義(P>0.05)。見表1。

2.2SDI相關因素分析年齡、身高、BMI、全髖及股骨頸BMD與SDI呈顯著相關，r值分別為0.361、-0.334、0.179、-0.409、-0.364，P均<0.01。

2.3SDI影響因素的回歸分析各因素對SDI影響程度大小依次為全髖BMD、身高、股骨頸BMD、年齡及BMI,其中全髖BMD對SDI影響最大。見表2。

表1　2組患者臨床基本信息比較s)

表2　年齡、身高、BMI、髖部BMD對SDI影響的線性回歸分析

3　討論

OVCF發病率較高,但因其癥狀隱匿常常受到忽視,僅1/3左右表現出腰背痛、活動障礙等明顯癥狀[6-7],故目前僅有約20%的OVCF患者得到確診[8]。有研究表明約一半的骨質疏松骨折發生于骨量減少階段[9],本研究發現這在OVCF發病中同樣適用,目前國內外多種指南已建議將胸腰段側位片作為骨質疏松癥篩查的常規檢查項目[1,10],其與BMD測定結合可顯著提高骨質疏松癥的檢出率[11]。臨床分析發現90%的椎體骨折發生于胸腰段,又由于T11～L2為脊柱應力集中點及生理性應力薄弱點(缺乏肋骨的有效保護),使其成為骨折最易發部位[12],這與本研究結果相一致。

增齡是骨質疏松骨折發生的主要危險因素,美歐的流行病學調查表明,50～60歲女性OVCF發病率約為5%～10%,并以每年約0.9%的速度遞增,而>80歲的患者發病率可達30%以上,我國的相關流行病學調查亦顯示了類似的結果[13-15]。身高變矮是OVCF的重要征象,目前認為身高較峰值降低>3 cm應高度懷疑OVCF的存在[15-16]。本研究表明,OVCF患者較正常人具有明顯較低的身高水平,且SDI值越高,身高相對越低,但本研究不足之處在于未采集患者的初始身高資料,無法評價身高變矮程度。體質量與骨質疏松骨折的關系,目前多認為低體質量是骨質疏松骨折發生的次要危險因素[17],朱梅等[18]研究表明體質量適量增加有利于骨量保持及降低骨質疏松骨折的發生,而以脂肪組織增加為主的肥胖則會導致骨量下降及骨質疏松骨折發生率上升,本研究結果顯示體質量與OVCF無相關性,分析BMI與SDI相關為算法所致,無臨床意義。

目前,DXA測量值為診斷骨質疏松的金標準,一般依據腰椎和髖部的測量結果[19]。林華等[20]研究表明腰椎BMD降低與絕經后女性OVCF相關,髖部BMD降低在一定程度上也能提示骨折的危險性。考慮到腰椎BMD受椎體骨折影響較大,本研究選取了髖部BMD作為研究指標,發現OVCF患者髖部BMD均在骨量減少水平以下,其中近一半患者的髖部BMD處于骨質疏松階段,從而明確提示了骨量丟失為OVCF的高危因素,另外,OVCF的程度(SDI值)與髖部BMD的下降程度一致,提示OVCF發生風險及嚴重程度具有BMD依賴性。

綜上所述,骨量丟失、增齡是絕經后女性骨質疏松性椎體壓縮性骨折發生的危險因素,且隨著骨量丟失、增齡程度的增加,骨折發生風險及嚴重程度逐漸上升。

[1]中華醫學會骨質疏松和骨礦鹽疾病分會.原發性骨質疏松癥診治指南(2011)[J].中華骨質疏松與骨礦鹽疾病雜志, 2011, 3(4):2-17.

[2]Suzuki N, Ogikubo O, Hansson T. The prognosis for pain, disability, activities of daily living and quality of life after an acute osteoporotic vertebral body fracture: its relation to fracture level, type of fracture and grade of fracture deformation [J]. Eur Spine J, 2009, 18(1):77-88.

[3]Genant HK, Wu CY, van Kuijk C, et al. Vertebral fracture assessment using a semi quantitative technique[J].Bone Miner Res,1993,8(9):1137-1148.

[4]Genant HK, Siris E, Crans GG, et al. Reduction in vertebral fracture risk in teriaparatide-treated postmenopausal women as assessed by spinal deformity index[J]. Bone, 2005,37(2):170-174.

[5]Tsang SW, Bow CH, Chu EY, et al. Clinical risk factor assessment had better discriminative ability than bone mineral density in identifying subjects with vertebral fracture[J]. Osteoporos Int, 2011, 22(2): 667-674.

[6]Rao RD, Singrakhia MD. Painful osteoporotic vertebral fracture[J].J Bone Joint Surg Am,2003,85-A(10):2010-2022.

[7]Delmas PD, Van de Langerijt L, Watts NB, et al. Under-diagnosis of vertebral fractures is a worldwide problem-the IMPACT Study[J].J Bone Miner Res,2005,20(4):557-563.

[8]Melton LJ, Riggs BL, Keaveny TM, et al. Relation of vertebral deformities to bone density, structure, and strength[J]. J Bone Miner Res, 2010, 25(9): 1922-1930.

[9]Schuit SC, van der Klift M, Weel AE, et al. Fracture incidence and association with bone mineral density in elderly men and women: the Rotterdam Study[J]. Bone, 2004, 34(1):195-202.

[10]Kanis JA, McCloskey EV, Johansson H, et al. European guidance for the diagnosis and management of osteoporosis in postmenopausal women[J]. Osteoporos Int, 2013, 24(1):23-57.

[11]Jager PL, Jonkman S, Koolhaas W, et al. Combined vertebral fracture assessment and bone mineral density mea-surement: a new standard in the diagnosis of osteoporosis in academic populations[J].Osteoporos Int,2011,22(4):1059-1068.

[12]Kim BG, Dan JM, Shin DE. Treatment of Thoracolumbar Fracture[J].Asian Spine J,2015,9(1):133-146.

[13]Wong CC, McGirt MJ. Vertebral compression fractures: a review of current management and multimodal therapy[J]. J Multidiscip Healthc, 2013, 6: 205-214.

[14]安珍,楊定焯,張祖君,等.骨質疏松性脊椎壓縮性骨折流行病學調查分析[J]. 中國骨質疏松雜志,2002,8(1):82-84.

[15]Vokes TJ, Gillen DL. Using clinical risk factors and bone mineral density to determine who among patients undergoing bone densitometry should have vertebral fracture assessment[J]. Osteoporos Int, 2010, 21(12): 2083-2091.

[16]Briot K, Legrand E, Pouchain D, et al. Accuracy of patient-reported height loss and risk factors for height loss among postmenopausal women[J].CMAJ, 2010, 182(6): 558-562.

[17]中華醫學會骨科學分會.骨質疏松骨折診療指南[J].中華骨科雜志, 2008, 28(10):875-878.

[18]賈紅蔚,朱梅.老年肥胖與骨質疏松[J].實用老年醫學, 2014, 28(11):887-890.

[19]丁宏, 徐秋貞, 鄧鋼, 等.影像學與骨質疏松癥關系的研究進展[J].實用老年醫學, 2011, 25(4):280-283.

[20]林華, 朱秀芬. 絕經后婦女椎體骨折與骨密度的對照研究[J].中國骨質疏松雜志, 2008, 14(7):512-514.

Correlation between hip bone density, age and vertebral fracture in postmenopausal women

CAOWei,ZHUXiu-fen,CHENXin,LINHua.

DepartmentofOrthopedics,theAffiliatedDrumTowerHospitalofNanjingUniversityofChineseTraditionalMedicine,Nanjing210008,China

ObjectiveTo analyze the correlation of vertebral fracture with hip bone density, age, height, weight, and body mass index in postmenopausal women.MethodsA retrospective analysis of the clinical data of postmenopausal women first examined and treated in department of orthopedics of our hospital from January 2012 to June 2015 was carried out. Age, height, weight and hip (total hip and femoral neck)bone mineral density(BMD) of patients were collected. Vertebral changes of patients were evaluated through X ray of thoracolumbar lateral, and the spinal deformity index(SDI) was calculated to reflect the general situation of vertebral fracture. The clinical data were analyzed and compared between vertebral fracture group and non vertebral fracture group. Spearman test was used to analyze the correlation between SDI with age, height, weight, body mass index (BMI) and hip BMD. Linear regression analysis was also used to explore the risk factor of SDI.Results213 cases were enrolled, of which 114 patients presented with osteoporotic vertebral fractures (53.52%), while the other 99 cases did not suffer from osteoporotic vertebral fractures (46.49%).There were 278 vertebral bodies involved, of which the top 5 were L1(51, 18.35%), T12 (48, 17.27%), T11(45,16.19%), L4(29,10.43%), T7(28,10.07%). Based on BMD of hip, in the osteoporotic-vertebral-fracture group there were 50 cases (43.86%) diagnosed as osteoporosis and the other 63 cases (56.14%) being in the stage of bone mass reduction, while only 23 cases could be diagnosed as osteoporosis in the non-vertebral-osteoporotic-fracture group (23.23%). Vertebral fracture group showed higher age, lower height and lower total hip and femoral neck BMD (P<0.001). While there were no statistical differences in weight and BMI between the two groups. Age, height, BMI, hip BMD were significantly correlated with SDI(r=0.361,-0.334, 0.179,-0.409,-0.364, respectively, allP<0.001). Linear regression analysis show that Age, height, BMI, hip BMD were independent risk of SDI.ConclusionsDecreased of hip BMD, and increased of age are the risk factors of osteoporotic vertebral fractures.

osteoporotic fracture; vertebral fracture; hip bone mineral density; spinal deformity index

江蘇省政府科技課題科技支撐計劃(社會發展)項目(BE2011605)

210008江蘇省南京市，南京中醫藥大學附屬南京鼓樓醫院骨病中心

林華，Email: lh2116@126.com

R 683.2

Adoi:10.3969/j.issn.1003-9198.2016.05.007

2015-10-13)