Undiagnosed prediabetes is highly prevalent in primary infertile men results from a cross-sectional study Luca Boeri* , Paolo Capogrosso* , Eugenio Ventimiglia* , Filippo Pederzoli* , Nicola Frego* , Walter Cazzaniga* , Francesco Chierigo* , Massimo Alfano*, Lorenzo Piemonti § , Paola Vigan o , Marina Pontillo**, Emanuele Montanari , Francesco Montorsi* and Andrea Salonia* *Division of Experimental Oncology/Unit of Urology, URI, IRCCS Ospedale San Raffaele, Department of Urology, Foundation IRCCS CaGranda Ospedale Maggiore Policlinico, University of Milan, University Vita-Salute San Raffaele, § Diabetes Research Institute, Infertility Unit, Unit of Obstetrics/Gynecology, and **Laboratory Medicine Service, IRCCS Ospedale San Raffaele, Milan, Italy Objective To study the prevalence and the risk associated with prediabetes (PreDM) in primary infertile men. Patients and methods Data from 744 infertile men were analysed. Health- signicant comorbidities were scored with the Charlson Comorbidity Index (CCI). Serum hormones were measured in every man. Semen analysis was based on 2010 World Health Organization (WHO) reference criteria. PreDM was dened according to the clinical criteria detailed by the American Diabetes Association (Diabetes Care 2014; 37 (Suppl. 1): S81). Descriptive statistics and logistic regression analyses tested the association between PreDM status, hormonal milieu and seminal parameters. The predictive accuracy of all variables was evaluated using the area under the curve, and the clinical net benet estimated by decision curve analysis (DCA). Results Of the 744 men, PreDM was found in 114 (15.4%). Men with PreDM (+PreDM) were older, had higher CCI scores, lower total testosterone and sex hormone-binding globulin but higher follicle-stimulating hormone (FSH) and 17b-oestradiol values compared to those without PreDM (ÀPreDM) (all P 0.04). Higher sperm DNA fragmentation index (DFI; P = 0.014) and idiopathic non-obstructive azoospermia (iNOA; P < 0.001) were found more frequently in +PreDM men. At multivariable logistic regression analysis, older age, FSH and iNOA (all P 0.04) were signicantly associated with +PreDM status. DCA demonstrated a clinical net benet in discriminating men at higher risk of a +PreDM status. Conclusions About 15% of primary infertile men had criteria suggestive of undiagnosed PreDM. A PreDM status was associated with a greater risk of hypogonadism, higher DFI values and iNOA status. Age, FSH values and iNOA status could be considered as useful parameters to recognise men with PreDM and implement early preventive interventions in those men at risk of the consequences from poor glycaemic control. Keywords prediabetes, infertility, risk factors, testosterone, nonobstructive azoospermia, #Testosterone, #Infertility, #Andrology Introduction Infertility is dened as the inability of a couple to achieve pregnancy despite unprotected intercourse for a period of >12 months [1]. About 15% of all couples are infertile, and it is estimated that a male factor plays a role in about half of the cases [2]. Recent data suggest that men with male factor infertility (MFI) may have a lower general health status, with a higher risk of developing tumours and age-related diseases, such as cardio-vascular and metabolic disorders [36]. In this context, various studies have focused on the association between male infertility and impaired glucose metabolism [7]. Glucose metabolism has emerged to be essential not only for testicular and epididymal function but also for sperm cell development and quality [8,9]. Furthermore, an abnormal glucose homeostasis has been associated with adverse © 2018 The Authors BJU International © 2018 BJU International | doi:10.1111/bju.14558 BJU Int 2018 Published by John Wiley & Sons Ltd. www.bjui.org wileyonlinelibrary.com