Risk of functional ovarian cyst: effects of smoking and marijuana use according to body mass index.

Smoking is one of the few risk factors that have been identified for functional ovarian cysts, and results of one epidemiologic study suggest that body mass index (BMI; weight (kg)/height (m)(2)) may modify the effect of this exposure. The current study assessed the association of cigarette smoking and marijuana use with functional ovarian cyst risk by using data from a population-based 1990-1995 case-control study of 586 incident functional ovarian cyst cases and 757 age-matched controls in a large health maintenance organization in Washington State. In multivariate analyses controlling for age, education, and reference year, the authors found an increase in risk associated with current cigarette smoking among women whose BMI was <20 (odds ratio (OR) = 2.48, 95% confidence interval (CI): 1.32, 4.64) or 20-25 (OR = 1.60, 95% CI: 1.04, 2.46) but not >25 (OR = 0.85, 95% CI: 0.53, 1.37). Corresponding risks associated with current marijuana use were BMI <20, OR = 2.05 (95% CI: 0.89, 4.75); BMI 20-25, OR = 1.78 (95% CI: 1.00, 3.17); and BMI >25, OR = 0.72 (95% CI: 0.36, 1.42). Study results indicate that increased BMI may attenuate the adverse effect of smoking on the risk of functional ovarian cyst.