title: Small-fibre neuropathy in men with type 1 diabetes and erectile dysfunction: a cross-sectional study.
abstract: The aim of this study was to identify the contribution of small- and large-fibre neuropathy to erectile dysfunction in men with type 1 diabetes mellitus.
  
  
  
  A total of 70 participants (29 without and 41 with erectile dysfunction) with type 1 diabetes and 34 age-matched control participants underwent a comprehensive assessment of large- and small-fibre neuropathy.
  
  
  
  The prevalence of erectile dysfunction in participants with type 1 diabetes was 58.6%. After adjusting for age, participants with type 1 diabetes and erectile dysfunction had a significantly higher score on the Neuropathy Symptom Profile (mean ± SEM 5.3 ± 0.9 vs 1.8 ± 1.2, p = 0.03), a higher vibration perception threshold (18.3 ± 1.9 vs 10.7 ± 2.4 V, p = 0.02), and a lower sural nerve amplitude (5.0 ± 1.1 vs 11.7 ± 1.5 mV, p = 0.002), peroneal nerve amplitude (2.1 ± 0.4 vs 4.7 ± 0.5 mV, p < 0.001) and peroneal nerve conduction velocity (34.8 ± 1.5 vs 41.9 ± 2.0 m/s, p = 0.01) compared with those without erectile dysfunction. There was also evidence of a marked small-fibre neuropathy with an impaired cold threshold (19.7 ± 1.4°C vs 27.3 ± 1.8°C, p = 0.003), warm threshold (42.9 ± 0.8°C vs 39.0 ± 0.9°C, p = 0.005) and heart rate variability (21.5 ± 3.1 vs 30.0 ± 3.7 beats/min, p = 0.001) and reduced intraepidermal nerve fibre density (2.8 ± 0.7 vs 5.9 ± 0.7/mm, p = 0.008), corneal nerve fibre density (12.6 ± 1.5 vs 23.9 ± 2.0/mm2, p < 0.001), corneal nerve branch density (12.7 ± 2.5 vs 31.6 ± 3.3/mm2, p < 0.001) and corneal nerve fibre length (8.3 ± 0.7 vs 14.5 ± 1.0 mm/mm2, p < 0.001) in participants with type 1 diabetes and erectile dysfunction. Erectile dysfunction correlated significantly with measures of both large- and small-fibre neuropathy.
  
  
  
  Small-fibre neuropathy is prominent in patients with type 1 diabetes, and is associated with erectile dysfunction and can be objectively quantified using corneal confocal microscopy. This may allow the identification of patients who are less likely to respond to conventional therapies such as phosphodiesterase type 5 inhibitors.
authors.affiliation: Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester and Central Manchester NHS Foundation Trust, Manchester Academic Health Science Centre, 46 Grafton Street, Core Technology Facility, Manchester, M13 9NT, UK.
authors.forename: Shazli
authors.initials: S
authors.lastname: Azmi
authors.affiliation: Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester and Central Manchester NHS Foundation Trust, Manchester Academic Health Science Centre, 46 Grafton Street, Core Technology Facility, Manchester, M13 9NT, UK.
authors.forename: Maryam
authors.initials: M
authors.lastname: Ferdousi
authors.affiliation: Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester and Central Manchester NHS Foundation Trust, Manchester Academic Health Science Centre, 46 Grafton Street, Core Technology Facility, Manchester, M13 9NT, UK.|Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK.
authors.forename: Uazman
authors.initials: U
authors.lastname: Alam
authors.affiliation: Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester and Central Manchester NHS Foundation Trust, Manchester Academic Health Science Centre, 46 Grafton Street, Core Technology Facility, Manchester, M13 9NT, UK.
authors.forename: Ioannis N
authors.initials: IN
authors.lastname: Petropoulos
authors.affiliation: Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester and Central Manchester NHS Foundation Trust, Manchester Academic Health Science Centre, 46 Grafton Street, Core Technology Facility, Manchester, M13 9NT, UK.|Department of Medicine, Weill Cornell Medicine-Qatar, Doha, Qatar.
authors.forename: Georgios
authors.initials: G
authors.lastname: Ponirakis
authors.affiliation: Department of Clinical Neurophysiology, Central Manchester NHS Foundation Trust, Manchester, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Marshall
authors.affiliation: Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester and Central Manchester NHS Foundation Trust, Manchester Academic Health Science Centre, 46 Grafton Street, Core Technology Facility, Manchester, M13 9NT, UK.
authors.forename: Omar
authors.initials: O
authors.lastname: Asghar
authors.affiliation: Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester and Central Manchester NHS Foundation Trust, Manchester Academic Health Science Centre, 46 Grafton Street, Core Technology Facility, Manchester, M13 9NT, UK.
authors.forename: Hassan
authors.initials: H
authors.lastname: Fadavi
authors.affiliation: Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester and Central Manchester NHS Foundation Trust, Manchester Academic Health Science Centre, 46 Grafton Street, Core Technology Facility, Manchester, M13 9NT, UK.
authors.forename: Wendy
authors.initials: W
authors.lastname: Jones
authors.affiliation: Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester and Central Manchester NHS Foundation Trust, Manchester Academic Health Science Centre, 46 Grafton Street, Core Technology Facility, Manchester, M13 9NT, UK.|Department of Medicine, The University of Exeter Medical School, Exeter, UK.
authors.forename: Mitra
authors.initials: M
authors.lastname: Tavakoli
authors.affiliation: Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester and Central Manchester NHS Foundation Trust, Manchester Academic Health Science Centre, 46 Grafton Street, Core Technology Facility, Manchester, M13 9NT, UK.
authors.forename: Andrew J M
authors.initials: AJM
authors.lastname: Boulton
authors.affiliation: Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester and Central Manchester NHS Foundation Trust, Manchester Academic Health Science Centre, 46 Grafton Street, Core Technology Facility, Manchester, M13 9NT, UK.
authors.forename: Maria
authors.initials: M
authors.lastname: Jeziorska
authors.affiliation: Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester and Central Manchester NHS Foundation Trust, Manchester Academic Health Science Centre, 46 Grafton Street, Core Technology Facility, Manchester, M13 9NT, UK.
authors.forename: Handrean
authors.initials: H
authors.lastname: Soran
authors.affiliation: Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia.
authors.forename: Nathan
authors.initials: N
authors.lastname: Efron
authors.affiliation: Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester and Central Manchester NHS Foundation Trust, Manchester Academic Health Science Centre, 46 Grafton Street, Core Technology Facility, Manchester, M13 9NT, UK. rayaz.a.malik@manchester.ac.uk.|Department of Medicine, Weill Cornell Medicine-Qatar, Doha, Qatar. rayaz.a.malik@manchester.ac.uk.
authors.forename: Rayaz A
authors.initials: RA
authors.lastname: Malik
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology*; D003928:Diabetic Nephropathies / Q000503:physiopathology*; D007172:Erectile Dysfunction / Q000503:physiopathology*; D006801:Humans; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged
keywords: Corneal confocal microscopy; Erectile dysfunction; Neuropathy; Small-fibre neuropathy; Type 1 diabetes