The impact of cigarette smoking on the plasma concentrations of gonadotrophins, ovarian steroids and androgens and upon the metabolism of oestrogens in the human female.

This study compares the plasma gonadotrophin, oestradiol, and androgen and salivary progesterone concentrations in a single menstrual cycle between 25 normal pre-menopausal women who smoke cigarettes and 21 who are non-smokers. The effect of smoking on luteinizing hormone (LH) pulsatility and the urinary excretion of oestrogens is also described. Cigarette smoking did not consistently suppress LH pulsatility. There was no significant difference in the length of either the follicular or luteal phases. There were no significant differences in the mean plasma oestradiol concentrations in the follicular phase in smokers compared to non-smokers. There were no significant differences in the mean salivary progesterone concentration in the luteal phase in smokers compared to non-smokers. There was no significant difference in plasma concentrations of testosterone, androstenedione and dehydroepiandrosterone sulphate. There was also no significant difference between the urinary concentrations of oestradiol, oestrone or oestriol. We have been unable to demonstrate a detrimental effect of cigarette smoking on any of the important endocrine characteristics of the menstrual cycle, and we conclude that these data suggest that the anti-oestrogenic effect of smoking does not work through alterations in pituitary or follicular endocrine function or in alterations in the metabolism of oestrogens.