Smoking, oral contraceptives, and obesity. Effects on white blood cell count
I. R. Fisch and S. H. Freedman
Data from 14,961 healthy women were analyzed to determine the relative
importance of factors that alter the white blood cell (WBC) count. The
effects of smoking, oral contraceptive use, and obesity were most striking.
A total leukocyte count greater than 10,00/cu mm was found in 44% of obese,
heavily smoking women who took oral contraceptives (central 95% of the
distribution was 5,800 to 14,200/cu mm) as compared to 2% of women without
these attributes (3,500 to 9,400/cu mm). Other factors such as age, time of
day, phase of the menstrual cycle, and red blood cell variables were of
lesser significance. The use of noncontraceptive estrogenic hormones did
not affect the WBC count. Recognition of these findings is important
because excessive laboratory studies, lost physician time, and patient
inconvenience may thereby be avoided.
