Smoking, alcohol consumption, and risk of systemic lupus erythematosus in the Black Women's Health Study.
OBJECTIVE
Several case-control studies, mostly of prevalent disease, have suggested that systemic lupus erythematosus (SLE) is positively associated with cigarette smoking and inversely associated with alcohol consumption. We prospectively investigated the associations of smoking and alcohol consumption with incident SLE in the Black Women's Health Study (BWHS).


METHODS
In 1995, 64,500 African-American women provided information on demographic characteristics, reproductive and medical histories, smoking, and alcohol consumption. Followup questionnaires in 1997 and 1999 ascertained incident cases of SLE. Cox proportional hazards regression was used to estimate incidence rate ratios (IRR) and 95% confidence intervals (CI).


RESULTS
Sixty-seven women reported a new diagnosis of SLE and use of appropriate medication for that illness. In multivariate analyses, the IRR for current and past smoking were 1.6 (both 95% CI 0.8-3.3). The risk was greater for women who began smoking before age 19 years (IRR 1.9, 95% CI 1.0-3.6). Neither current alcohol consumption (IRR 1.0, 95% CI 0.4-2.4) nor past alcohol consumption (IRR 0.9, 95% CI 0.3-2.7) was associated with SLE.


CONCLUSIONS
Our results suggest an increased risk of SLE among smokers, but no effect of alcohol consumption on risk. The inverse association of alcohol consumption with SLE found in studies of prevalent disease may have resulted from women with SLE giving up drinking.
Formica
Margaret K
MK
Clinical Epidemiology Research and Training Unit and the Slone Epidemiology Center, Boston University School of Medicine, Massachusetts 02118, USA.
Palmer
Julie R
JR
Rosenberg
Lynn
L
McAlindon
Timothy E
TE
D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data*; D000428:Alcohol Drinking / Q000208:ethnology*; D005260:Female; D006801:Humans; D015994:Incidence; D008180:Lupus Erythematosus, Systemic / Q000208:ethnology*; D008875:Middle Aged; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D012907:Smoking / Q000208:ethnology*; D016387:Women's Health