To ascertain whether smoking or alcohol consumption is associated with lupus erythematosus (LE), because this topic is still subject to debate and part of the debate could be related to the fact that smoking and alcohol consumption are specific risk factors for cutaneous LE.
Prospective multicenter case-control study.
Three French university hospitals.
One hundred eight patients with LE and 216 control subjects.
Standardized questionnaire evaluating cigarette smoking and alcohol consumption.
Main Outcome Measures
The statistical significance of smoking history and alcohol consumption as associated risk factors for LE by estimating matched case-control odds ratios and their 95% confidence intervals, using multiple conditional logistic regression and the Breslow-Day test to investigate differences in quantities of cigarette and alcohol consumption.
Of the LE patients, 73.1% smoked compared with 49.5% of controls, (odds ratio, 2.77; 95% confidence interval, 1.63-4.76). There was no significant difference in alcohol consumption between LE patients and controls. Among the 79 LE patients who smoked, 72 (91.1%) had started smoking before the first manifestation of LE (mean delay between initiation of smoking and first signs of LE, 14.1 years). The LE patients smoked significantly more than controls did (11.7 vs 7.0 pack-years; P = .002). The prevalence of smoking among patients who met more than 4 American College of Rheumatology (ACR) criteria and/or with antinuclear DNA antibodies was lower than the prevalence in patients who met fewer than 4 ACR criteria or than the prevalence in controls (P < .001).
Cigarette smoking is associated with LE, but alcohol consumption is not. The risk conferred by cigarette smoking seems highest in patients who meet fewer than 4 ACR criteria and/or who do not have antinuclear DNA antibodies.