The Impact of Obesity on Sperm Parameters in Young Adult Males: A Retrospective Study of Sperm Donors

Abstract

To utilize a large cohort of healthy sperm bank donors to evaluate the association between body mass index and individual sperm parameters. Sperm parameters from donors across the United States were obtained between 2013 and 2022. Donors were healthy men aged 18-46years old. Semen samples were analyzed in a certified lab following guidelines by the World Health Organization. A multivariable interaction model between age, body mass index, and sperm parameters was conducted. There were 117,357 sperm donations included in our study. In our sample, 98,397 (83.84%) men were classified as young donors (ages 18-32years) and 18,960 (16.16%) were classified as old donors (ages 33-46years). We identified 1032 (0.88%) men as underweight, 76,635 (65.30%) as normal weight, 36,686 (31.26%) as overweight, and 3004 (2.56%) as obese. Participants had a median total motile sperm count (TMSC) of 186 (interquartile ranges [IQR]: 128 million), volume of 3.36 (IQR: 1.82 mL), sperm concentration of 56 (IQR: 34 million/mL) and a progressive motility of 59.84% (IQR: 16.95%). Older obese donor had lower TMSC (β = -22.98 ± 4.66, P < .001), semen volumes (β = -0.85 ± 0.06, P < .001), and progressive motility (β = -3.94 ± 0.56, P < .001) compared to younger, healthy weight donors. We observed lower TMSC, semen volumes, and progressive motility in older obese donors. Although these values are within the normal expected ranges for individual sperm parameters, our ability to detect differences within this healthy population highlights the importance of maintaining a healthy diet and exercise regimen for preserving high sperm counts.