Lifestyle-, environmental-, and additional health factors associated with an increased sperm DNA fragmentation: a systematic review and meta-analysis

• Published in: Reproductive biology and endocrinology Vol. 21; no. 1; p. 5
• Main Authors: Szabó, Anett, Váncsa, Szilárd, Hegyi, Péter, Váradi, Alex, Forintos, Attila, Filipov, Teodóra, Ács, Júlia, Ács, Nándor, Szarvas, Tibor, Nyirády, Péter, Kopa, Zsolt
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 18-01-2023; BioMed Central; BMC
• Subjects: DFI; Diagnosis; DNA Fragmentation; Environmental aspects; Glucose Intolerance - pathology; Health aspects; Humans; Infertility; Infertility, Male; Infertility, Male - genetics; Life Style; Male; Male fertility; Middle Aged; Prognostic factors; Reproductive medicine; Review; Risk factors; Semen; Sperm quality; Spermatozoa - pathology; Testicular Neoplasms - pathology; Varicocele - pathology; Hungary; Male fertility; SDF; DFI; Infertility; Reproductive medicine; Sperm quality; DNA fragmentation index; Sperm DNA fragmentation; Prognostic factors
• ISSN: 1477-7827; 1477-7827
• DOI: 10.1186/s12958-023-01054-0

Infertility affects one in every six couples in developed countries, and approximately 50% is of male origin. In 2021, sperm DNA fragmentation (SDF) testing became an evidence-based test for fertility evaluations depicting fertility more clearly than standard semen parameters. Therefore, we aimed to summarize the potential prognostic factors of a higher SDF.
We conducted a systematic search in three medical databases and included studies investigating any risk factors for SDF values. We calculated mean differences (MD) in SDF with 95% confidence interval (CI) for exposed and non-exposed individuals.
We included 190 studies in our analysis. In the group of associated health conditions, varicocele (MD = 13.62%, CI: 9.39-17.84) and impaired glucose tolerance (MD = 13.75%, CI: 6.99-20.51) had the most significant increase in SDF. Among malignancies, testicular tumors had the highest impact, with a maximum of MD = 11.3% (CI: 7.84-14.76). Among infections, the overall effects of both Chlamydia and HPV were negligible. Of lifestyle factors, smoking had the most disruptive effect on SDF - an increase of 9.19% (CI: 4.33-14.06). Different periods of sexual abstinence did not show significant variations in SDF values. Age seemed to have a more drastic effect on SDF from age 50 onwards, with a mean difference of 12.58% (CI: 7.31-17.86). Pollution also had a detrimental effect - 9.68% (CI: 6.85-12.52).
Of the above risk factors, varicocele, impaired glucose tolerance, testicular tumors, smoking, pollution, and paternal age of over 50 were associated with the highest SDF.
CRD42021282533.