Severe obesity linked to high risk of low sperm count

Kiarad Fendereski, MD

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Patients with severe obesity may be at a 70% increased risk of low sperm count, and a 16% increased risk of azoospermia, according to new study findings.¹

In new abstract data presented at the Sexual Medicine Society of North America (SMSNA) 2024 Fall Scientific Meeting in Scottsdale, AZ this week, a team of investigators from the University of Utah observed multiple urological and otherwise medical comorbidities associated with sperm quality in a cohort of men with either oligospermia or azoospermia. The data may help clinicians identify patients at higher risk of lowered sperm count based on their clinical characteristics.

Investigators led by Kiarad Fendereski, MD, a research associate in the division of urology, department of surgery, University of Utah, conducted their cohort analysis of adult men to interpret the impact of comorbidities and clinical characteristics on oligospermia or azoospermia.

“Recent evidence suggests that sperm quality can serve as a potential marker for overall health, as various genetic and environmental factors can impact both a man's reproductive and somatic health,” the team wrote. “Previous findings indicate that poor semen quality may be associated with higher mortality from chronic conditions, decreased lifespan, and increased risks of cardiovascular disease, metabolic syndrome, and autoimmune conditions.”

The team used the multicenter TriNetX database to design a cohort of men >18 years old who had undergone semen analysis. Comorbidities for each patient were determined via diagnostic coding. Investigators excluded patients with HIV, hepatitis B or C virus, cancer, a history of vasectomy and retrograde ejaculation.

Patients were stratified based on diagnosis of either oligospermia or azoospermia; men without either diagnosis were considered normozoospermic. Urological and medical comorbidities linked to the status of impaired semen were determined for each patient group; investigators conducted multivariate analyses to define the significance of association.

Of the approximate 2.25 million individuals to undergo semen analysis in the cohort, 1.88 million men met the inclusion criteria. Among them, 5832 (0.31%) were oligospermic, 5638 (0.3%) were azoospermic, and the remaining 1,874,198 (99.39%) were normospermic.

The most common urologic comorbidity among oligospermic men was varicocele—prevalent in 17.3% of such patients. It was additionally prevalent in 6.7% of azoospermic men, and just 0.4% of normospermic men (P <.001).

The most common urologic comorbidity among azoospermic men was testicular artrophy, impacting 3.5% of patients. It additionally impacted 2.3% of oligospermic men, and 0.1% of normospermic men (0.1%; P <.001).

Autoimmune diseases additionally were the most common medical comorbidities among patients with either oligospermia (16.9%) or azoospermia (15.7%), though 13.2% of normospermic men additionally had autoimmune disease (P <.001).

In the multivariate analysis, severe obesity (defined as body mass index ≥40 kg/m²) was associated with a significantly increased risk of oligospermia (odds ratio [OR], 1.7; 95% CI, 1.68 – 1.71) as well as azoospermia (OR, 1.16; 95% CI, 1.15 – 1.17; P <.001). Investigators additionally observed significantly increased risk of poor semen quality among men with sexually transmitted infections, testicular trauma or hypofunction, and increased age.

The association between high BMI and fertility risk has been previously well established; a 2023 study from Italy showed obesity, hyperinsulinemia and insulin resistance in even childhood could eventually put men at greater risk of infertility in later life.²

Fendereski and colleagues conclude their findings show a clear association between high BMI and poor semen count status in adulthood as well.¹

“In conclusion, our study shows that severe obesity can lead to a higher risk of impaired sperm quality surpassing the impact of certain urological factors traditionally linked to impaired semen parameters,” investigators wrote. “These findings underscore the significance of addressing obesity as a key factor in male fertility assessment.”

References

1. ^{Fendereski K, Horns JJ, Dehghanbanadaki H, Schardein JN, et al. The Association Between Semen Quality and Comorbidities Using a Large Database. Paper presented at: Sexual Medicine Society of North America (SMSNA) 2024 Fall Scientific Meeting. Scottsdale, AZ. October 17 – 21, 2024.}
2. ^{Clarke H. Childhood obesity is associated with infertility in men. Urology Times. Published May 24, 2023. https://www.urologytimes.com/view/childhood-obesity-is-associated-with-infertility-in-men}