Aldhous Marian C, Drummond Hazel E, Anderson Niall, Baneshi M Reza, Smith Linda A, Arnott Ian D R, Satsangi Jack
Gastrointestinal Unit, Molecular Medicine Centre, School of Molecular and Clinical Medicine, University of Edinburgh, Western General Hospital, Edinburgh, Scotland, UK.
Am J Gastroenterol. 2007 Mar;102(3):589-97. doi: 10.1111/j.1572-0241.2007.01065.x.
Cigarette smoking affects susceptibility to ulcerative colitis (UC), but its effects on age at diagnosis, disease extent, and need for surgery are less well defined. We examined these parameters in a detailed retrospective analysis of a large cohort of well-characterized UC patients.
499 UC patients (254 male, median age 34.3 yr) were studied. Data were collected on smoking habits, smoking load (pack-years), age at recruitment, age at diagnosis, surgery, and disease extent. Colonoscopic and histological data at both diagnosis and follow-up (median follow-up time 4.6 yr) were available on 349 patients.
Ex-smokers were older at diagnosis than current or nonsmokers, (46.5 yr vs 31.1 or 29.4 yr, respectively, P < 0.001). Before diagnosis, ex-smokers had a higher smoking load than current smokers (13.0 vs 6.94 pack-years, P < 0.001). A Cox model for age at diagnosis, with smoking as a time-dependent covariate, showed that at any age, ex-smokers were significantly more likely to develop UC than current smokers (hazard ratio 1.8, 95% CI 1.41-2.44, P < 0.001). For current smokers at latest colonoscopy, those with extensive disease were the lightest smokers (median 0.320 pack-years), whereas those with healthy colons were the heaviest smokers (median 9.18 pack-years, P= 0.006). At 5 yr, regression of extensive disease was more frequent in current than ex-smokers or nonsmokers (30% current smokers vs 8% nonsmokers and 5% ex-smokers, chi(2)= 30.4, P < 0.001) but these differences were not maintained over a longer time period.
Smoking habit influences the age at diagnosis and changes in disease extent in UC. Mechanisms are likely to be complex and require further investigation.
吸烟会影响溃疡性结肠炎（UC）的易感性，但其对诊断年龄、疾病范围和手术需求的影响尚不太明确。我们在一项对大量特征明确的UC患者队列的详细回顾性分析中研究了这些参数。
对499例UC患者（254例男性，中位年龄34.3岁）进行了研究。收集了吸烟习惯、吸烟量（包年数）、招募时年龄、诊断年龄、手术情况和疾病范围的数据。349例患者可获得诊断时和随访时（中位随访时间4.6年）的结肠镜检查和组织学数据。
已戒烟者诊断时的年龄比当前吸烟者或从不吸烟者大（分别为46.5岁、31.1岁或29.4岁，P<0.001）。在诊断前，已戒烟者的吸烟量高于当前吸烟者（13.0包年数对6.94包年数，P<0.001）。以吸烟作为时间依赖性协变量的诊断年龄Cox模型显示，在任何年龄，已戒烟者患UC的可能性均显著高于当前吸烟者（风险比1.8，95%CI 1.41-2.44，P<0.001）。对于最新结肠镜检查时的当前吸烟者，广泛性疾病患者吸烟量最轻（中位0.320包年数），而结肠健康者吸烟量最重（中位9.18包年数，P=0.006）。在5年时，广泛性疾病缓解在当前吸烟者中比已戒烟者或从不吸烟者更常见（当前吸烟者为30%，从不吸烟者为8%，已戒烟者为5%，χ(2)=30.4，P<0.001），但这些差异在更长时间段内未持续存在。
吸烟习惯会影响UC的诊断年龄和疾病范围变化。其机制可能很复杂，需要进一步研究。
