体质指数对强直性脊柱炎患者临床特征的影响

目的探讨体质指数（BMI）对强直性脊柱炎（AS）患者临床特征的影响。方法收集2008～2011年确诊的AS患者125例,分为BMI1（体重过低）组,共36例;BMI2（体重正常）组,共63例;BMI3（超重）组,共26例,比较不同BMI组AS患者临床特征的异同。结果 （1）BMI1、BMI2和BMI3组中以腰痛为首发症状的患者比例分别为47.2%、60.3%、80.8%;以外周关节炎为首发症状的患者比例分别为52.8%、39.7%、19.2%（χ2=7.141,P=0.028）;3组AS患者间的关节功能、X线分期、HLA-B27及X线上脊柱竹节样变发生率的比较无统计学差异（P=0.475）。（2）血沉分别为（53.47±27.69）mm/1h、（50.55±31.45）mm/1h、（34.60±30.09）mm/1h,F=3.287,P=0.041]和胸廓活动度分别为（3.67±1.52）cm、（3.14±1.30）cm、（2.47±1.79）cm,F=4.450,P=0.014]在3组AS间明显不同,而其他指标比较无差别（P〉0.05）。（3）相关性分析结果显示：BMI与AS患者的胸廓扩张度（r=-0.281,P〈0.0001）、血沉（r=-0.252,P〈0.0001）呈负相关,与晨僵时间（r=0.202,P=0.029）呈正相关,而与其他指标间无相关性（P〉0.05）。（4）LinearRegression（Backward法）分析发现CRP（t=2.961,P=0.004,β=0.310,95%CI：0.002～0.011）和晨僵时间（t=3.323,P=0.001,β=0.322,95%CI：0.009～0.036）为影响强直性脊柱炎疾病活动指数（BASDAI）的因素（R2=0.304,F=9.636,P〈0.0001）。CRP（t=4.462,P=0.004,β=0.419,95%CI：0.006～0.015）、枕墙距（t=2.142,P=0.036,β=0.221,95%CI：0.004～0.106）和病程（t=2.398,P=0.019,β=0.247,95%CI：0.012～0.134）为影响BASDAI的因素（R2=0.362,F=11.789,P〈0.0001）。结论不同BMI对AS患者临床特征有影响,BMI越高的AS患者越易以腰痛为首发症状,其晨僵时间越长、胸廓扩张度和血沉越低。但BMI对AS患者BASDAI和BASFI指标无影响。

Influences of body mass index on the clinical features of patients with ankylosing spondylilis

Objective To explore the influences of body mass index （BMI）on the clinical features of patients with ankylosing spondylitis（AS）. Methods 125 patients with AS were divided into three groups, BMll （low weight） group of 36 eases, BMI2 （ normal body weight ） group of 63 cases and BMI3 （overweight） group of 26 cases. The clinical features among the three groups were investigated. Results （ 1 ） Percentages of first starting symptom with back pain among BMI1 ,BMI2 and BMI3 groups were 47.2% ,60. 3% and 80. 8% ,while that of the first signs with peripheric arthritis were 52. 8% ,39. 7% and 19.2% （ X^2 = 7. 141 ,P = 0. 028 ）. Joint function, X-ray stages of sacroiliitis ,positive rate of HLA-B27 and the incidence of bamboo-like spine among three groups differed from each other（ P = 0. 475 ）. （ 2 ） Erythrocyte sedimentation rate （ 53.47 ± 27.69 ）/1 h, （ 50. 55-± 31.45 ）/1 h, （ 34. 60 ± 30.09）/1 h,F = 3.287,P = 0.041] and thoracic distensibility （3.67 ± 1.52）cm, （3.14 ± 1.30）cm, （2.47 ± 1.79） cm,F = 4. 450, P = 0. 014] among the three groups were significantly different, while other indicators had no difference（P 〉0. 05 ）. （ 3 ） BMI negatively correlated with thoracic distensibility （ r = - 0. 281, P 〈 0. 0001 ） and erythrocyte sedimentation rate （ r = - 0. 252, P 〈 0. 0001 ）. There was a positive correlation between BMI and duration of morning stiffness （ r = 0. 202, P = 0. 029 ）. （ 4 ） Linear Regression （ Backward method） analysis showed that CRP （ t = 2. 961,P = 0. 004 ,β = 0. 310,95 % CI： 0. 002-0.011 ） and duration of morning stiffness （ t = 3. 323, P = 0. 001, = 0. 322,95 % CI：0. 009-0. 036） were factors for the changes of BASDAI in AS （R2 = 0. 304, F = 9. 636, P 〈 0. 0001 ）.CRP（t = 4. 462, P = 0. 004 ,β = 0. 419,95% CI： 0. 006-0. 015 ）, pillow away from wall （ t = 2. 142, P = 0. 036 ,/3 = 0. 221,95% CI：0. 004-0. 106） and duration of disease （t = 2. 398 ,P = 0. 019,β= 0. 247,95% CI：0. 012-0. 134） were contributed factors of BASDAI in AS （ R^2 = 0. 362, F = 11. 789, P 〈 0. 0001 ）. Conclusions BMI does affect clinical manifestations of AS. The higher BMI of patient is, the more percentage of first signs with back pain is, the longer duration of morning stiffness is ,the less thoracic distensibility and erythroeyte sedimentation rate are. But BMI has no effect on BASDAI and BASFI in patients with AS.