Diabetic Neuropathy and Erectile Dysfunction: Unveiling the Neural Pathways Behind a Vascular Symptom

Erectile dysfunction (ED) is one of the most prevalent and disabling complications of diabetes mellitus (DM), thought to arise from the interaction of metabolic, vascular, and neural injury. Recent evidence indicates that diabetic neuropathy, affecting both somatic and autonomic pathways, plays a central role in the development of ED and is strongly associated with increased disease burden. Early neurophysiological studies documented impaired penile sensory conduction and abnormalities of sacral reflex pathways in diabetic men with ED, while more recent investigations have confirmed the contribution of cardiovascular autonomic neuropathy and small-fibre loss. At the molecular level, oxidative stress, advanced glycation end-product signalling, impaired nitric oxide bioavailability, and reduced neurotrophic support, particularly involving brain-derived neurotrophic factor (BDNF), emerge as key mechanisms linking diabetes to neural and neurovascular dysfunction. Although phosphodiesterase type-5 inhibitors remain first-line therapy, reduced responsiveness in patients with significant neuropathy highlights the importance of recognising the role of neurogenic mechanisms. Overall, the available evidence supports the conceptualisation of diabetic ED as a neurovascular manifestation within the broader spectrum of diabetic neuropathy rather than as a purely vasculogenic disorder. This review integrates historical and contemporary literature addressing the epidemiology, neurophysiology, pathophysiology and therapeutic implications of ED in diabetes, with a specific focus on its neuropathic substrate. These findings support a paradigm shift toward an integrated neurovascular approach to diabetic ED, highlighting the importance of early neuropathy-oriented assessment and paving the way for future regenerative and neuroprotective therapeutic strategies.