Short-Term High-Altitude Exposure (3600 m) Alters the Type Distribution of Sperm Deformity

The effect of short-term exposure to high altitudes below 4000 m on the distribution of sperm abnormality is a matter of concern with regard to the ability for fertilization, and rarely reported. The survey subjects, who had not visited the high plateau previously, were divided into three groups: two high-plateau groups and the low-altitude control group. In the high-plateau groups, healthy young men had been living in Lhasa City, Tibet (3600 m), for 1 or 3 months. Similar subjects in Chongqing City (400 m) were used as the control group. Semen was collected, and semen volume, pH, and sperm concentration were analyzed. After observing sperm morphology by light microscopy, we measured the percentage of sperm abnormality and statistically analyzed its type distribution. Sperm concentration was decreased significantly after 3 months of high-altitude exposure (p < 0.01). The total sperm malformation rate did not change, but the head malformation rate was increased (p < 0.05). In addition, there were changes in the distribution of sperm malformation. The occurrence and frequency of sperm with excessive head size, neck crimp, and tailless were increased significantly (p < 0.01, p < 0.01, and p < 0.05, respectively) at 3 months. Our study demonstrates that short-term high-altitude exposure of >1 month at 3600 m increases the distribution of sperm deformities.