Psychological stress and testicular function: a cross-sectional study of 1,215 Danish men

Abstract

To study the associations between self-reported psychological stress, semen quality, and serum reproductive hormones among young Danish men. Cross-sectional study. University hospital-based research center. Danish men (median age 19 years) from the general population were investigated from 2008 to 2012. Participants completed a questionnaire on health and lifestyle, including a four-item questionnaire about self-rated stress, had a physical examination performed, delivered a semen sample, and had a blood sample drawn. Semen parameters (semen volume, sperm concentration, and percentages of motile and morphologically normal spermatozoa) and serum levels of reproductive hormones (LH, FSH, T, calculated free T, sex hormone-binding globulin, and inhibin B). Poorer semen quality was detected among men with self-reported stress scores above an intermediate stress level, in a dose-response manner. For example, men with the highest stress levels had 38% (95% confidence interval [CI] 3%; 61%) lower sperm concentration, 34% (95% CI 59%; 106%) lower total sperm count, and 15% (95% CI 1%; 27%) lower semen volume than men with intermediate stress levels. No significant associations between self-reported stress and levels of reproductive hormones were detected. A negative association between self-reported stress and semen quality was detected. If causal, stress may be a contributing factor for suboptimal semen quality among otherwise healthy men.