LAUSR

BACKGROUND Infertile men have shown a worse overall health status compared to the fertile counterpart. OBJECTIVE We aimed to i) assess kidney function in men presenting for primary couple's infertility compared to fertile men; and, ii) assess kidney function impairment toward sperm quality in infertile men. MATERIALS & METHODS In this case-control study 387 consecutive white-European infertile men were matched by age with 134 same-ethnicity fertile men. Complete clinical and laboratories data were available for each patient. The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) function was used for estimated glomerular filtration rate (eGFR) calculation. Kidney functional impairment was defined as an eGFR<90 ml/min/1.73m2 , according to the Kidney Disease Improving Global Outcomes criteria. Multivariable logistic regression analysis was used to i) assess the association between kidney function impairment and infertility status; and, ii) investigate the association between kidney function and semen analysis abnormalities in infertile men. RESULTS After matching, 34 (8.8%) infertile men depicted at least a mild unknown impairment of kidney function compared to only 4 (3%) fertile men, with 4 (3%) of the infertile presenting with an overt kidney function impairment (eGFR<60 ml/min /1.73m2 ). There were no differences in terms of age, BMI and rate of comorbidities between the two groups (all p>0.05). After adjusting for major confounders, infertility status was associated with a higher risk of reduced eGFR (OR 3.20; 1.21-5.2; p = 0.002). Conversely, eGFR was not associated with sperm abnormalities in infertile men. CONCLUSIONS Mild kidney function impairment was found in 9% of asymptomatic and unaware men presenting for primary couple's infertility investigation. This novel finding corroborates growing data on a significant association of male infertility with a poorer overall male health status and the need for tailored preventive strategies. This article is protected by copyright. All rights reserved.