Gender differences in circulating bubble production after SCUBA diving

Differences in circulating bubble production have been described after exposures in altitude chambers between men and women. The present study was designed to examine gender differences in circulating bubble production after a dive.

Fifty-two men and 52 women performed the same dive profile (25 min to 35 m). Circulating bubbles were detected by continuous wave Doppler. Tests were conducted at sea in a boat, at 10-min intervals for 1 h after surfacing. Signals were graded according to the Spencer scale. The categorical data were then converted to a single number reflecting total bubble activity using the KISS index.

Considering each measurement period, bubble grade was higher in men than women 30, 40 and 50 min postdive. On the contrary, bubble grade was comparable between men and women 10, 20 and 60 min after the dive. KISS index was significantly higher in men than women (6.77 [0.65-32.3] versus 0.91 [0-22.9], P<0.02). KISS index was significantly correlated with age, weight and body fat mass in the whole population and in the men and women separately. Postmenopausal women had a higher KISS index (42 [15-47]) when compared with premenopausal women and men older than 50 years. No difference in bubble production was found according to the use of oral contraceptive pills or the phase of the menstrual cycle.

Overall, we observed fewer circulating bubbles in women than in men after an open sea SCUBA dive. This difference disappeared in the postmenopausal women.