Archive | 2021
Sperm mitochondrial DNA copy numbers in normal and abnormal semen analysis: a systematic review and meta-analysis.
Abstract
Background: Normal mature sperm have a considerably reduced number of\nmitochondria which provide the energy required for progressive sperm\nmotility. Literature suggests that disorders of sperm motility may be\nlinked to abnormal sperm mitochondrial number and function. Objectives:\nTo summarise the evidence from literature regarding the association of\nmitochondrial DNA copy numbers and semen quality with a particular\nemphasis on the spermatozoa motility. Search strategy: Standard\nmethodology recommended by Cochrane. Selection criteria: All published\nprimary research reporting on differences in mitochondrial DNA copy\nnumbers between the sperm of males with a normal and abnormal semen\nanalysis. Data collection and analysis: Using standard methodology\nrecommended by Cochrane we pooled results using a random effects model\nand the findings were reported as a standardised mean difference. Main\nresults: We included 10 trials. The primary outcome was sperm\nmitochondrial DNA copy numbers. A meta-analysis including five studies\nshowed significantly higher mitochondrial DNA copy numbers in abnormal\nsemen analysis as compared to normal semen analysis(SMD 1.08, 95% CI\n0.74-1.43). Three other studies not included in the meta-analysis showed\na significant negative correlation between mitochondrial DNA copy\nnumbers and semen parameters. The quality of evidence was assessed as\ngood to very good in 60% of studies. Conclusions: Our review\ndemonstrates significantly higher mitochondrial DNA in human sperm cells\nof men with abnormal semen analysis in comparison to men with normal\nsemen analysis. PROSPERO registration: CRD42019118841 Funding None\nreceived