Influence of Body Mass Index (BMI) and Waist–Hip Ratio (WHR) on Selected Semen Parameters

Because male obesity may result in reproductive failure, we aimed to examine the possible links among body mass index (BMI), the waist–hip ratio (WHR), and basic semen parameters, the oxidation–reduction potential of semen, the total antioxidant capacity of seminal plasma, the ability of sperm to bind hyaluronic acid, and sperm DNA fragmentation (SDF). This study was performed on semen (n = 543) collected from volunteers classified as follows: normal weight (BMI 18.5–24.9 kg/m²), overweight (BMI 25.0–29.9 kg/m²), obese (BMI ≥ 30.0 kg/m²), with a normal WHR (<1) or abnormal WHR (≥1). No significant differences in standard semen parameters were found between men with a normal BMI and those with overweight/obesity. However, compared with overweight men, obese men had a higher SDF index prevalence and risk for an SDF index > 20%. Compared with men with WHR < 1, those with WHR ≥ 1 had significantly lower sperm motility, morphology, and vitality and an increased SDF index, prevalence and risk for an SDF index > 20%. In conclusion, abnormal WHR had a greater negative impact on conventional semen parameters than abnormal BMI. Both BMI ≥ 30.0 and WHR ≥ 1 negatively influenced sperm chromatin integrity only. Obesity is a potential risk factor for sperm DNA damage.