Publication:

Lisinopril, an angiotensin converting enzyme inhibitor for the treatment of idiopathic oligospermia: a randomized controlled trial

Background Oligospermia or low concentration of sperm is a common finding in male infertility. Alterations in the expression of angiotensin converting enzyme (ACE) may be one of the mechanisms underlying male infertility and ACE inhibitors may improve the sperm count. The objective was to compare the effects of lisinopril and zinc-folic acid with zinc-folic acid alone on idiopathic oligospermia in infertile males.

Methods This randomized controlled trial was conducted in the Department of Reproductive Endocrinology & Infertility of a medical university from March 2021 to February 2022. A total 78 diagnosed cases of infertile males with idiopathic oligospermia were selected for this study. Eligible men who gave their informed consent were randomly allocated to receive either a combination of low dose lisinopril (2.5 mg) and zinc-folic acid or zinc-folic acid alone for 12 weeks. Pretreatment and post treatment semen parameters, including sperm concentration, sperm motility and total motile sperm count were assessed.

Results There was significant rise in sperm concentration and total motile sperm count in both groups but the mean difference in sperm concentration (2.36±2.04 vs 1.53±1.8 million/ml) and total motile sperm count (11.64±8.28 vs 9.95±6.11 million) were higher in those receiving Lisinopril in addition to zinc folic acid. The percentage increase of sperm count was higher (22.65 vs 16.70 million) in this group. Normalization of sperm count (sperm count ≥15 million/ml) was also higher in this group (18.4% vs 8.3%) with relative risk 2.21, 95% CI (0.648-4.56 %).

Conclusions Lisinopril given orally at the dosage of 2.5 mg/day with zinc-folic acid for 12 weeks appears to be well tolerated among men with oligospermia and improves sperm count by a small margin when compared to zinc folic acid only.