(199) The Impact of Obesity on Sperm Parameters in Young Adult Males: A Retrospective Study of Sperm Donors
Authors: Gurayah A , Grewal M , Venigalla G , Miller D , Ramasamy R 
Published: February 2024

Abstract

Introduction
Studies estimate that sperm concentrations have declined by 52.4% over the past 40 years. Concurrent with this decline in male fertility, obesity remains a growing epidemic in the United States, with the prevalence in men rising from 26.6% in 1999 to 38.4% in 2016. Thus, this decline in sperm concentration may be attributable to many causes, including lifestyle factors such as obesity. The gold standard diagnostic method for assessing male fertility is semen analysis. Due to screening criteria, sperm banks offer a unique sample of individual-level semen analyses of healthy men without comorbidities including cardiovascular disease, hypertension, heart failure, and diabetes. While the association between BMI and sperm parameters has previously been shown, these studies do not exclude individuals with obesity-related comorbidities, as participants presented as couples who were seeking care for infertility.

Objective
To utilize a large sample of healthy young men who meet strict sperm bank donor eligibility criteria to evaluate the association between BMI and individual sperm parameters, independent of comorbidities.

Methods
Sperm parameters from donor candidates at sperm banks across the United States were obtained between 2008 to 2021. Donors were healthy men aged 18-46 years old who abstained from ejaculation for 48 hours prior to donation. Semen samples were analyzed in a Clinical Laboratory Improvement Amendments (CLIA) certified lab using guidelines by the World Health Organization (WHO). A univariable model between BMI and individual sperm parameters (total sperm count, volume, sperm concentration, progressive motility) was conducted.

Results
There was a total of 135,578 sperm donations included in our study. The median age was 26 (IQR: 8), with 1146 (0.8%) men identified as underweight, 89,590 (66%) as normal weight, 41,362 as overweight (31%), 3,438 (3%) as obesity class I and 42 (0.03%) as obesity class II (Table 1). Participants had a median total motile sperm count of 194 (IQR: 134 million), volume of 3.45 (IQR: 1.8mL), sperm concentration of 58 (IQR: 34 million/mL) and a motility of 61.5 (IQR: 18%). We found that total motile sperm count (B = -69, p &lt; 0.01) and volume (B = -1.14, p &lt;0.01) were significantly lower in men with a BMI ≥ 35, compared to normal weight men (sperm count = 213 million; volume = 3.67 mL; Table 2).

Conclusions
We report significantly lower total sperm count and semen volume in healthy young men who have a BMI ≥ 35 as compared to those who are normal weight. Although these values are within the normal range of sperm parameters established by the WHO, our ability to detect differences even within this specific population of men without obesity-related comorbidities highlights the importance of maintaining a healthy weight for preserving high sperm counts. With the increase in infertility concerns amongst younger men and the rise of obesity prevalence within the United States, our work highlights the importance of maintaining a healthy diet and exercise regimen throughout early adulthood to maintain normal sperm parameters.

Disclosure
No.