Self-Reported Asthma Is Associated with Reduced Sperm Count—A Cross-Sectional Study of More than 6000 Young Men from the General Population

Abstract

Asthma is driven by an inflammatory response that may impact testicular function. In this cross-sectional study, we investigated the association between self-reported asthma and testicular function (semen parameters, reproductive hormone levels), and determined whether potential further inflammation due to self-reported allergy modified this association. A total of 6177 men from the general population completed a questionnaire including information on doctor-diagnosed asthma or allergy, had a physical examination, delivered a semen sample, and had a blood sample drawn. Multiple linear regression analyses were performed. A total of 656 (10.6%) men reported having ever been diagnosed with asthma. Generally, self-reported asthma was consistently associated with a poorer testicular function; however, few estimates were statistically significant. Specifically, self-reported asthma was associated with statistically significant lower total sperm count [median: 133 vs. 145 million; adjusted β (95% CI): −0.18 (−0.33 to −0.04) million on cubic-root-transformed scale] and borderline statistically significant lower sperm concentration compared with no self-reported asthma. The association between asthma and total sperm count was of similar magnitude among men with and without allergy. In conclusion, men with self-reported asthma had poorer testicular function than men without asthma. However, the cross-sectional design of the study limits ascertainment of causality.

Genetically predicted asthma and the risk of abnormal spermatozoa

“…In addition, only one cross-sectional study in humans found a potential association between self-reported asthma patients and reduced testicular function, primarily manifested by decreased spermatozoa concentration and total spermatozoa count. However, no significant differences were observed in semen volume, spermatozoa motility, or spermatozoa morphology ( Pedersen et al, 2023 ). The findings from the above studies have proved a negative correlation between asthma and spermatozoa quality.…”

“…As illustrated in animal models, male mice with asthma were related to abnormal spermatozoa and testicular structure ( Xu et al, 2016 ; Deng et al, 2021 ; Wang et al, 2021 ; Feng et al, 2022 ). Moreover, a cross-sectional study in humans showed that men with asthma had lower spermatozoa concentration and total spermatozoa count compared with non-asthmatic men ( Pedersen et al, 2023 ). The findings from the above studies have proved a negative correlation between asthma and spermatozoa quality.…”