Resting pulmonary ventilation and dead space ventilation during the menstrual cycle

By reanalyzing our previous study (TAKANO et al., 1981) of resting ventilation and PACO2 during the menstrual cycle of eight healthy women, we found that relative to the follicular phase, a 9.4% increase in VA (p less than 0.05) and a 2.5 mmHg decrease in PACO2 (p less than 0.001) occurring during the luteal phase, both of which have been reported previously, were attributable mostly to a decrease in VD (-7.2%, 0.05 less than p less than 0.1) but not to an increase in VE (+1.9%, N.S.), the latter two changes producing an 8.7% decrease in VD/VT (p less than 0.01).