Telomeres are essential for the integrity of chromosome ends during cell division and their involvement in different processes linked to aging has been established. These chromosome components are involved in spermatogenesis and seem to play an important role in fertilization and embryo development. Telomere length is shortened with each cell division. Recently, short sperm telomere length has been proposed as a potential biomarker of male infertility.
To conduct a systematic review and meta-analysis of studies exploring the association between sperm and/or leukocyte telomere length with sperm quality parameters and different infertility conditions.
A systematic review and meta-analysis was conducted with studies from Medline-PUBMED and Cochrane Library databases until May 2022. Eligible studies included cohort, cross-sectional and case-control studies, and telomere length in sperm and/or leukocytes cells was defined as the exposure. Semen quality parameters or infertility conditions (e.g., oligozoospermia, asthenozoospermia, teratozoospermia, or other spermatogenic impairment combinations) were defined as the outcomes.
Twenty-four observational studies were included. In the qualitative analysis, high heterogeneity was observed between studies regarding the associations between telomere length and semen parameters in different normozoospermic/fertile and oligozoospermic/infertile populations. In the meta-analysis, sperm and leukocyte telomere length were shorter in infertile compared to fertile individuals (mean difference, MD; 95% confidence interval, CI) (-1.43; -1.66 to -1.21; P-value<0.001, and -1.67; -2.02 to -1.31; P-value<0.001, respectively). Moreover, in terms of sperm telomere length, these differences were also significant between individuals with a normal seminogram and individuals with low quantity of spermatozoa in the ejaculate (-0.97; -1.32, -0.61; P-value<0.001).
The current systematic review and meta-analysis suggest the potential role of sperm or leukocyte telomere length as a reliable biomarker of semen quality, which may help distinguish between infertility conditions beyond the routine semen analysis. This article is protected by copyright. All rights reserved.
Andrology. 2023 Jun 16 [Epub ahead of print]
María Fernández de la Puente, Albert Salas-Huetos, Cristina Valle-Hita, Nancy Babio, Michelle M Murphy, Silvia Canudas, Jordi Salas-Salvadó
Departament de Bioquímica i Biotecnologia, Unitat de Nutrició Humana, Universitat Rovira i Virgili, Reus, Spain., Consorcio CIBER, M.P. Fisiopatología de la Obesidad y Nutrición (CIBERObn), Instituto de Salud Carlos III (ISCIII), Madrid, Spain., Department of Nutrition, Food Sciences and Gastronomy, School of Pharmacy and Food Sciences, Food Torribera Campus, University of Barcelona, Santa Coloma de Gramenet, Spain.