Leung Y Y, Ang L W, Thumboo J, Wang R, Yuan J M, Koh W P
Duke-NUS Graduate Medical School Singapore, Singapore; Department of Rheumatology and Immunology, Singapore General Hospital, Singapore.
Epidemiology & Disease Control Division, Ministry of Health, Singapore.
Osteoarthritis Cartilage. 2014 Jun;22(6):764-70. doi: 10.1016/j.joca.2014.03.013. Epub 2014 Mar 28.
Data on the effects of cigarette smoking with osteoarthritis (OA) are inconsistent and no study has examined the effect of smoking cessation. We examined smoking status, duration, dosage and cessation in association with risk of total knee replacement (TKR) for severe knee OA among elderly Chinese in Singapore.
We used data from the Singapore Chinese Health Study, a population-based prospective cohort of 63,257 Chinese men and women aged 45-74 years during enrollment between 1993 and 1998. Detailed information on smoking, current diet and lifestyle factors were obtained through in person interviews. As of 31 December 2011, 1,973 incident TKR cases for severe knee OA had been identified via linkage with nationwide hospital discharge database. We used Cox regression methods to examine smoking in relation to TKR risk with adjustment for age, gender, education, body mass index (BMI), comorbidities and physical activity level.
Compared to never smokers, current smokers had a 51% decrease in risk of TKR [Hazards ratio (HR) = 0.49; 95% confidence interval (CI) = 0.40-0.60]. Among current smokers, there was a very strong dose-dependent association between increasing duration and dosage of smoking with decreasing risk of TKR (P for trend <0.0001). Among former smokers, there was a dose-dependent response between decrease in duration of smoking cessation and reduction in TKR risk (P for trend = 0.034).
Our findings strongly implicate smoking as a protective factor for TKR indicated for severe knee OA. This concurs with experimental data that nicotine promotes proliferation and collagen synthesis in chondrocytes.
关于吸烟与骨关节炎（OA）关系的数据并不一致，且尚无研究探讨戒烟的影响。我们研究了吸烟状况、持续时间、吸烟量及戒烟情况与新加坡老年华裔严重膝关节OA行全膝关节置换术（TKR）风险之间的关联。
我们使用了新加坡华人健康研究的数据，这是一项基于人群的前瞻性队列研究，纳入了1993年至1998年期间年龄在45 - 74岁的63257名华裔男性和女性。通过面对面访谈获取了关于吸烟、当前饮食和生活方式因素的详细信息。截至2011年12月31日，通过与全国医院出院数据库的关联，确定了1973例严重膝关节OA的新发TKR病例。我们使用Cox回归方法，在调整年龄、性别、教育程度、体重指数（BMI）、合并症和身体活动水平后，研究吸烟与TKR风险的关系。
与从不吸烟者相比，当前吸烟者的TKR风险降低了51%[风险比（HR）= 0.49；95%置信区间（CI）= 0.40 - 0.60]。在当前吸烟者中，吸烟持续时间和吸烟量增加与TKR风险降低之间存在非常强的剂量依赖性关联（趋势P < 0.0001）。在既往吸烟者中，戒烟持续时间的减少与TKR风险降低之间存在剂量依赖性反应（趋势P = 0.034）。
我们的研究结果有力地表明吸烟是严重膝关节OA行TKR的一个保护因素。这与尼古丁促进软骨细胞增殖和胶原蛋白合成的实验数据一致。
