Shan-Jun Zheng

Background: 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. Materials and Methods: 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. Results: 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. Conclusion: Our study demonstrates that short-term high-altitude exposure of >1 month at 3600 m increases the distribution of sperm deformities.

Background: Oxygen inhalation therapy is essential for the treatment of patients with chronic mountain sickness (CMS), but the efficacy of oxygen inhalation for populations at high risk of CMS remains unknown. This research investigated whether oxygen inhalation therapy benefits populations at high risk of CMS. Methods: A total of 296 local residents living at an altitude of 3658 m were included; of which these were 25 diagnosed cases of CMS, 8 cases dropped out of the study, and 263 cases were included in the analysis. The subjects were divided into high-risk (180 ≤ hemoglobin (Hb) n = 161) and low-risk (Hb n = 102) groups, and the cases in each group were divided into severe symptom (CMS score ≥6) and mild symptom (CMS score 0-5) subgroups. Severe symptomatic population of either high- or low-risk CMS was randomly assigned to no oxygen intake group (A group) or oxygen intake 7 times/week group (D group); mild symptomatic population of either high- or low-risk CMS was randomly assigned to no oxygen intake group (A group), oxygen intake 2 times/week group (B group), and 4 times/week group (C group). The courses for oxygen intake were all 30 days. The CMS symptoms, sleep quality, physiological biomarkers, biochemical markers, etc., were recorded on the day before oxygen intake, on the 15^th and 30^th days of oxygen intake, and on the 15^th day after terminating oxygen intake therapy. Results: A total of 263 residents were finally included in the analysis. Among these high-altitude residents, CMS symptom scores decreased for oxygen inhalation methods B, C, and D at 15 and 30 days after oxygen intake and 15 days after termination, including dyspnea, palpitation, and headache index, compared to those before oxygen intake (B group: Z = 5.604, 5.092, 5.741; C group: Z = 4.155, 4.068, 4.809; D group: Z = 6.021, 6.196, 5.331, at the 3 time points respectively; all P < 0.05/3 vs. before intake). However, dyspnea/palpitation (A group: Z = 5.003, 5.428, 5.493, both P < 0.05/3 vs. before intake) and headache (A group: Z = 4.263, 3.890, 4.040, both P < 0.05/3 vs. before intake) index decreased significantly also for oxygen inhalation method A at all the 3 time points. Cyanosis index decreased significantly 30 days after oxygen intake only in the group of participants administered the D method (Z = 2.701, P = 0.007). Tinnitus index decreased significantly in group A and D at 15 days (A group: Z = 3.377, P = 0.001, D group: Z = 3.150, P = 0.002), 30 days after oxygen intake (A group: Z = 2.836, P = 0.005, D group: Z = 5.963, P < 0.0001) and 15 days after termination (A group: Z = 2.734, P = 0.006, D group: Z = 4.049, P = 0.0001), and decreased significantly in the group B and C at 15 days after termination (B group: Z = 2.611, P = 0.009; C group: Z = 3.302, P = 0.001). In the population at high risk of CMS with severe symptoms, oxygen intake 7 times/week significantly improved total symptom scores of severe symptoms at 15 days (4 [2, 5] vs. 5.5 [4, 7], Z = 2.890, P = 0.005) and 30 days (3 [1, 5] vs. 5.5 [2, 7], Z = 3.270, P = 0.001) after oxygen intake compared to no oxygen intake. In the population at high risk of CMS with mild symptoms, compared to no oxygen intake, oxygen intake 2 or 4 times/week did not improve the total symptom scores at 15 days (2 [1, 3], 3 [1, 4] vs. 3 [1.5, 5]; χ² = 2.490, P = 0.288), and at 30 days (2 [0, 4], 2 [1, 4.5] vs. 3 [2, 5]; χ² = 3.730, P = 0.155) after oxygen intake. In the population at low risk of CMS, oxygen intake did not significantly change the white cell count and red cell count compared to no oxygen intake, neither in the severe symptomatic population nor in the mild symptomatic population. Conclusions: Intermittent oxygen inhalation with proper frequency might alleviate symptoms in residents at high altitude by improving their overall health conditions. Administration of oxygen inhalation therapy 2–4 times/week might not benefit populations at high risk of CMS with mild CMS symptoms while administration of therapy 7 times/week might benefit those with severe symptoms. Oxygen inhalation therapy is not recommended for low-risk CMS populations.

Astragalus is a traditional Chinese medicine to improve the function of the body. The purpose of this study is to investigate the effect of astragalus on improvement of anti-fatigue capacity in mice under simulated plateau environment. Male Kunming mice were randomly divided into the following groups: the control group, astragalus treatment groups in low dosage (LD) (1.0 g/kg·d), mid dosage (MD) (3.0 g/kg·d), and high dosage (HD) (30 g/kg·d). The control group were fed under normoxia environment, and hypoxic mice were fed at a stimulated elevation of 5000 meters. After continuous intragastric administration for 10 days, exhaustive swimming experiment was conducted in the anoxic environment. The swimming time, glucose and lactic acid concentration in blood, glycogen contents in liver, SOD and MDA were determined. Compared with the control group, the swimming time of each astragalus treated group was evidently prolonged (P < 0.05), and the area under the blood lactic acid curve was significantly decreased (P < 0.05). In the high and middle dose of astragalus group, liver glycogen was obviously increased. After exhausted swimming, glycogen contents in blood and SOD were significantly increased, while MDA was evidently reduced (P < 0.05). Astragalus can alleviate physical fatigue in mice under simulated plateau environment. It has an obvious anti-fatigue effect and it's worthy of further study.