[Comparison of sperm parameters between male adults at different altitudes]

To investigate the influence of long-term anoxic exposure on the sperm function of male adults at different altitudes.

A total of 28 male adults that had stayed at the altitude of 5 340 m for 1-3 years were included as a high-altitude group (HAG), 34 at the mean altitude of 3 800 m for 2-5 years as a middle-altitude group (MAG) and 31 permanently at the altitude of 1 300 m as controls. Semen specimens were collected and the real-time semen analysis was performed by using computer-assisted semen analysis (CASA) system.

The sperm density, VCL, VSL, VAP and LIN in the HAG were (51.12 +/- 14.61) x 10(6)/ ml, (48.17 +/- 13. 52) microm/s, (32.64 +/- 6.70) microm/s, (41.21 +/- 9.32) microm/s and 52.24 +/- 8.14, respectively, significantly lower than those of the control (P < 0.01 or P < 0.05). Compared with the control group, there was a progressive decrease in sperm concentration, sperm motility rate, VSL, VCL, LIN, VAP and ALH in the MAG.

The higher the altitude, the more obvious was the negative effect of anoxic exposure on the sperm function of male adults.