Small fibre pathology is associated with erectile dysfunction in men with type 2 diabetes

Non-medical and non-invasive interventions for erectile dysfunction in men with type 2 diabetes mellitus: A scoping review

Background

Erectile dysfunction (ED) often affects men with type 2 diabetes mellitus (T2DM) due to microvascular damage. However, medical interventions are not always appropriate.

Aim

This scoping review aimed to answer the following question: What evidence is available about the effects of non-medical and non-invasive healthcare interventions to improve ED in men with T2DM?

Method

Potential studies were collected from the Cumulative Index to Nursing and Allied Health Literature via EBSCO, Embase via Ovid, MEDLINE via Ovid, Web of Science, PubMed, ProQuest, and PsycINFO via Ovid.

Findings

From 2,611 identified titles, 17 studies, including 11 interventional and 6 observational studies, were included. Four main alternatives to medical interventions were identified from the included studies. Amongst these, four studies recommended patient education on lifestyle modification, twelve studies encouraged dietary changes and physical activities, two studies emphasized the use of vacuum erectile device, and three studies suggested the application of low-intensity extracorporeal shockwave therapy by healthcare professionals.

Discussion

Dietary modification and physical activities were promoted as effective interventions to help maintaining the erectile function in men with T2DM. Several methods of patient education were identified as the approach to facilitate lifestyle modification in men with T2DM-associated ED. The positive outcomes of this review support early ED screening to help preventing T2DM complications such as ED in men. Further, T2DM management is a shared responsibility between the men and healthcare professionals. Despite the success of Vacuum Erectile Device and Low-intensity Extracorporeal Shockwave Therapy in regaining erectile function, further research is needed in this area based on the recommendations of the American Urological Association. Moreover, the health and quality of life of men with T2DM must be improved.

Corneal Confocal Microscopy to Image Small Nerve Fiber Degeneration: Ophthalmology Meets Neurology

Neuropathic pain has multiple etiologies, but a major feature is small fiber dysfunction or damage. Corneal confocal microscopy (CCM) is a rapid non-invasive ophthalmic imaging technique that can image small nerve fibers in the cornea and has been utilized to show small nerve fiber loss in patients with diabetic and other neuropathies. CCM has comparable diagnostic utility to intraepidermal nerve fiber density for diabetic neuropathy, fibromyalgia and amyloid neuropathy and predicts the development of diabetic neuropathy. Moreover, in clinical intervention trials of patients with diabetic and sarcoid neuropathy, corneal nerve regeneration occurs early and precedes an improvement in symptoms and neurophysiology. Corneal nerve fiber loss also occurs and is associated with disease progression in multiple sclerosis, Parkinson's disease and dementia. We conclude that corneal confocal microscopy has good diagnostic and prognostic capability and fulfills the FDA criteria as a surrogate end point for clinical trials in peripheral and central neurodegenerative diseases.

Corneal Confocal Microscopy: A Biomarker for Diabetic Peripheral Neuropathy

PURPOSE

Diagnosing early diabetic peripheral neuropathy remains a challenge due to deficiencies in currently advocated end points. The cornea is densely innervated with small sensory fibers, which are structurally and functionally comparable to intraepidermal nerve fibers. Corneal confocal microscopy is a method for rapid, noninvasive scanning of the living cornea with high resolution and magnification.

METHODS

This narrative review presents the framework for the development of biomarkers and the literature on the use and adoption of corneal confocal microscopy as an objective, diagnostic biomarker in experimental and clinical studies of diabetic peripheral neuropathy. A search was performed on PubMed and Google Scholar based on the terms "corneal confocal microscopy," "diabetic neuropathy," "corneal sensitivity," and "clinical trials."

FINDINGS

A substantial body of evidence underpins the thesis that corneal nerve loss predicts incident neuropathy and progresses with the severity of diabetic peripheral neuropathy. Corneal confocal microscopy also identifies early corneal nerve regeneration, strongly arguing for its inclusion as a surrogate end point in clinical trials of disease-modifying therapies.

IMPLICATIONS

There are sufficient diagnostic and prospective validation studies to fulfill the US Food and Drug Administration criteria for a biomarker to support the inclusion of corneal confocal microscopy as a primary end point in clinical trials of disease-modifying therapies in diabetic neuropathy.