Effects of temperature anomaly on sperm quality: A multi-center study of 33,234 men

Lina Xiao; Qiling Wang; Haobo Ni; Ting Xu; Xiaoyan Cai; Tingting Dai; Lingxi Wang; Chunying Song; Yushan Li; Fuping Li; Tianqing Meng; Huiqiang Sheng; Xiaolin Yu; Qinghui Zeng; Pi Guo; Xinzong Zhang

doi:10.1016/j.heliyon.2024.e26765

Effects of temperature anomaly on sperm quality: A multi-center study of 33,234 men

Heliyon. 2024 Feb 22;10(5):e26765. doi: 10.1016/j.heliyon.2024.e26765. eCollection 2024 Mar 15.

Authors

Lina Xiao¹, Qiling Wang^{2

3}, Haobo Ni¹, Ting Xu¹, Xiaoyan Cai¹, Tingting Dai¹, Lingxi Wang¹, Chunying Song⁴, Yushan Li⁵, Fuping Li⁶, Tianqing Meng^{7

8}, Huiqiang Sheng⁹, Xiaolin Yu¹, Qinghui Zeng¹, Pi Guo¹, Xinzong Zhang^{2

3}

Affiliations

¹ Department of Preventive Medicine, Shantou University Medical College, Shantou, 515041, China.
² National Health Commission Key Laboratory of Male Reproduction and Genetics, Guangzhou, China.
³ Department of Andrology, Guangdong Provincial Reproductive Science Institute (Guangdong Provincial Fertility Hospital), China.
⁴ Human Sperm Bank, The Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Taiyuan, China.
⁵ Human Sperm Bank, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
⁶ Human Sperm Bank, The Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education, West China Second University Hospital of Sichuan University, Chengdu, China.
⁷ Reproductive Medicine Center, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
⁸ Human Sperm Bank, Reproductive Medicine Center, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
⁹ Human Sperm Bank, The Zhejiang Provincial Maternal and Child and Reproductive Health Care Center, Hangzhou, China.

Abstract

Backgrounds: Global fertility rates continue to decline and sperm quality is a prime factor affecting male fertility. Both extreme cold and heat have been demonstrated to be associated with decreased sperm quality, but no epidemiological studies have considered human adaptation to long-term temperature. Our aim was to conduct a multi-center retrospective cohort study to investigate exposure-response relationship between temperature anomaly (TA) that deviate from long-term climate patterns and sperm quality.

Methods: A total of 78,952 semen samples measured in 33,234 donors from 6 provincial human sperm banks in China were collected. This study considered heat and cold acclimatization to prolonged exposure in humans and explored the exposure-response relationship between TAs and sperm quality parameters (sperm concentrations, sperm count, progressive motility, progressive sperm count, total motility and total motile sperm count) during the hot and cold seasons, respectively. Linear mixed models and generalized linear models were built separately for specific centers to pool in a meta-analysis to obtain the pooled effect of TA on sperm quality, considering repeated measurements data structure and spatial heterogeneity.

Results: We identified an inverted U-shaped exposure-response relationship between TA and sperm quality during the hot season. Significant negative effect of anomalous cold on sperm quality during the hot season was found after additional adjustment for Body mass index, marital status and childbearing history. The heat-related TA in hot season was significantly negatively associated with sperm concentration, progressive sperm count and total motile sperm count (all P-values<0.05). After adjusting the relative humidity, the cold-related TA in cold season was negatively associated with the sperm total motility (P-values<0.05).

Conclusions: Our results suggest both heat-related and cold-related TAs are associated with decreased sperm quality. The findings highlight the importance of reducing exposure to anomalous temperatures to protect male fertility.

Keywords: Climate change; Exposure-response relationship; Human adaptation; Sperm quality; Temperature anomaly.