The impact of BMI on sperm parameters and the metabolite changes of seminal plasma concomitantly

// Dan Guo 1,2,* , Wei Wu 1,2,3,* , Qiuqin Tang 4,* , Shanlei Qiao 1,2 , Yiqiu Chen 1,2 , Minjian Chen 1,2 , Mengying Teng 1,2 , Chuncheng Lu 1,2 , Hongjuan Ding 4 , Yankai Xia 1,2 , Lingqing Hu 3 , Daozhen Chen 3 , Jiahao Sha 5 and Xinru Wang 1,2 1 State Key Laboratory of Reproductive Medicine, Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing, China 2 Key Laboratory of Modern Toxicology of Ministry of Education, Nanjing Medical University, Nanjing, China 3 State Key Laboratory of Reproductive Medicine, Wuxi Maternal and Child Health Care Hospital Affiliated to Nanjing Medical University, Wuxi, China 4 Department of Obstetrics, State Key Laboratory of Reproductive Medicine, Obstetrics and Gynecology Hospital Affiliated to Nanjing Medical University, Nanjing, China 5 State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China * These authors have contributed equally to this study Correspondence to: Wei Wu, email: // Xinru Wang, email: // Keywords : BMI, obesity, sperm parameters, meta-analysis, metabolomic analysis, Pathology Section Received : April 26, 2016 Accepted : December 16, 2016 Published : February 01, 2017 Abstract The development of male infertility increased rapidly worldwide, which coinciding with the epidemic of obesity. However, the impact of weight abnormalities on sperm quality is still contestable. To assess the correlation between BMI and sperm parameters, we searched relevant articles in PubMed, Embase, Web of science, and Wanfang database published until June 2015 without language restriction. Otherwise, we also recruited some participants who attended fertility clinic as well as some general populations in this report. We performed a systematic review and meta-analysis about BMI and sperm parameters containing total sperm count, concentration, semen volume and sperm motility (overall and progressive). Metabolomic analysis of seminal plasma was performed to explore the mechanism from a new perspective. This study found standardized weighted mean differences (SMD) in sperm parameters (total sperm count, sperm concentration, and semen volume) of abnormal weight groups decreased to different degree compared to normal weight. Dose-response analysis found SMD of sperm count, sperm concentration and semen volume respectively fell 2.4%, 1.3% and 2.0% compared with normal weight for every 5-unit increase in BMI. Metabolomic analysis of seminal plasma showed that spermidine and spermine were likely to play a vital role in the spermatogenesis progress. This systematic review with meta-analysis has confirmed there was a relationship between BMI and sperm quality, suggesting obesity may be a detrimental factor of male infertility.