Abstract

PIP: A review of the clinical effects of smoking on sex steroid production and clearance indicates a decrease in fecundity and duration of reproductive life span. Exogenous steroids from oral contraceptives and endogenous steroids are significant factors. Several studies are cited to illustrate the higher incidence of abnormal bleeding among smokers (1 pack/day equals a ratio of 1.67 with p.01 compared with 1.2 for those smoking 20/day). It was also determined that there was a higher incidence of hysterectomy among ex-smokers, 1 pack/day, and 1 pack/day smokers, i.e., 5% of ex-smokers, 6.8% for 1 pack/day, and 8.4% 1 pack/day smokers among women 30-39 years, with 14.8-16.1% having irregular menses. There was a higher incidence of infertility: 21.3% of smokers had no children by menopause compared with 14% among the total population. Smokers were found to have a lower pregnancy rate than nonsmokers with a dose-dependent relationship such that 12 months after contraceptive stoppage, of those smoking 11-15 cigarettes, 43.8% had not delivered. Of those smoking 21 or more cigarettes, 50.9% had not delivered compared with 41% of nonsmokers. Smokers had earlier menopause which was also associated with increased cigarette consumption. Hormone metabolism is affected through the production of cytochrome P-450 enzymes, which are altered to increase ovarian steroids. The polycyclic aromatic hydrocarbons found in cigarettes smoke induce arylhydrocarbon hydroxylase activity in mouse ovaries. Although in 1 study urinary estrogens increased during the follicular phase among smokers, the effect on estrogen production and clearance is still unclear. In a male dog study, testicular 6-alpha-testosterone hydroxylase was depressed, but not testicular 16-alpha- and 6-beta-testosterone hydroxylase. Hepatic 6-beta-testosterone and serum testosterone increased. Serum testosterone and prostate size decreased. Uncertainty remains ovver the P-450 dependent metabolic effects on mitochondrial conversion of cholesterol to pregnenolone. Smoking and oral contraceptive use are interactive.