INS and obesity due to melanocortin 4 receptor deficiency: Pitteloud et al. (2005) suggested that Leydig cell steroidogenesis is impaired in insulin-resistant states such as obesity and Leisegang et al. (2014) proposed that hyperinsulinemia is associated with increased seminal insulin concentrations, which may negatively impact the male reproductive function in the case of obesity [16; 7].