Mean cell volume in a working population: the effects of age, smoking, alcohol and oral contraception.

The effects of mean cell volume (MCV) of age, smoking habit, alcohol consumption, menopausal status, and use of oral contraceptives have been studied as appropriate in 1596 white men and 892 white women in working populations in North-West London. In men, increasing age, smoking and alcohol consumption each make an independent contribution to MCV. In women, the effect of smoking is similar to that in men; the effect of alcohol is less obvious, possibly because of the low stated alcohol intake in women. The effect of alcohol on MCV in the population studied is not as marked as in hospital patients who admit to excessive alcohol consumption; this may partly be due to differences in methods of eliciting intake. There is a small increase in MCV following the menopause. Women on oral contraceptives show a rise in MCV with increasing age; this is not seen in women not on oral contraceptives. There is a strong inverse association between MCV and red blood cell count, which may be part of a mechanism to ensure constant oxygen carrying capactiy.