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Khodaie SA, Razavi R, Nikkhah H, Namiranian N, Kamalinejad M. Nigella sativa L. and its bioactive and nutraceutical components in the management of diabetic peripheral neuropathy. Inflammopharmacology 2024:10.1007/s10787-024-01528-6. [PMID: 39143432 DOI: 10.1007/s10787-024-01528-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Accepted: 07/05/2024] [Indexed: 08/16/2024]
Abstract
Diabetes-induced hyperglycemia leads to excessive production of oxygen free radicals, inflammatory cytokines, and oxidative stress, which initiates diabetic peripheral neuropathy (DPN). Currently, this condition affects 20% of adults with diabetes. Despite significant advances in the treatment of diabetes, the incidence of its complications, including DPN, is still high. Thus, there is a growing research interest in developing more effective and treatment approaches with less side effects for diabetes and its complications. Nigella sativa L. (NS) has received much research attention as an antioxidant, anti-yperglycemic factor, and anti-inflammatory agent. This natural compound demonstrates its antidiabetic neuropathy effect through various pathways, including the reduction of lipid peroxidation, the enhancement of catalase and superoxide dismutase enzyme activity, and the decrease in inflammatory cytokine levels. The present review focuses on the bioactive and nutraceutical components of black cumin (Nigella sativa L.) and their effects on DPN. In addition, we have also summarized the findings obtained from several experimental and clinical studies regarding the antidiabetic neuropathy effect of NS in animal models and human subjects.
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Affiliation(s)
- Seyed-Ali Khodaie
- Diabetes Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Roghaye Razavi
- Diabetes Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Haniyeh Nikkhah
- Diabetes Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Nasim Namiranian
- Community & Preventive Medicine, Yazd Diabetes Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Mohammad Kamalinejad
- School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
- Behdane Baran Salem Abi Company, Tehran, Iran.
- AB Pharma inc267 Esplanade West, North Vancouver, BC, Canada.
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2
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Gad H, Elgassim E, Lebbe A, MacDonald RS, Baraka A, Petropoulos IN, Ponirakis G, Ibrahim NO, Malik RA. Corneal confocal microscopy detects early nerve regeneration after pharmacological and surgical interventions: Systematic review and meta-analysis. J Peripher Nerv Syst 2024; 29:173-184. [PMID: 38887985 DOI: 10.1111/jns.12641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 05/30/2024] [Accepted: 06/03/2024] [Indexed: 06/20/2024]
Abstract
Corneal confocal microscopy (CCM) is an ophthalmic imaging technique that enables the identification of corneal nerve fibre degeneration and regeneration. To undertake a systematic review and meta-analysis of studies utilizing CCM to assess for corneal nerve regeneration after pharmacological and surgical interventions in patients with peripheral neuropathy. Databases (EMBASE [Ovid], PubMed, CENTRAL and Web of Science) were searched to summarize the evidence from randomized and non-randomized studies using CCM to detect corneal nerve regeneration after pharmacological and surgical interventions. Data synthesis was undertaken using RevMan web. Eighteen studies including 958 patients were included. CCM identified an early (1-8 months) and longer term (1-5 years) increase in corneal nerve measures in patients with peripheral neuropathy after pharmacological and surgical interventions. This meta-analysis confirms the utility of CCM to identify nerve regeneration following pharmacological and surgical interventions. It could be utilized to show a benefit in clinical trials of disease modifying therapies for peripheral neuropathy.
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Affiliation(s)
- Hoda Gad
- Research Department, Weill Cornell Medicine-Qatar, Doha, Qatar
| | - Einas Elgassim
- Research Department, Weill Cornell Medicine-Qatar, Doha, Qatar
| | - Ahamed Lebbe
- Research Department, Weill Cornell Medicine-Qatar, Doha, Qatar
| | | | - Areej Baraka
- Research Department, Weill Cornell Medicine-Qatar, Doha, Qatar
| | | | | | - Nada O Ibrahim
- Research Department, Weill Cornell Medicine-Qatar, Doha, Qatar
| | - Rayaz A Malik
- Research Department, Weill Cornell Medicine-Qatar, Doha, Qatar
- Institute of Cardiovascular Medicine, University of Manchester, Manchester, UK
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Kong J, Zou R, Chu R, Hu N, Liu J, Sun Y, Ge X, Mao M, Yu H, Wang Y. An Ultrasmall Cu/Cu 2O Nanoparticle-Based Diselenide-Bridged Nanoplatform Mediating Reactive Oxygen Species Scavenging and Neuronal Membrane Enhancement for Targeted Therapy of Ischemic Stroke. ACS NANO 2024; 18:4140-4158. [PMID: 38134247 DOI: 10.1021/acsnano.3c08734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2023]
Abstract
Ischemic stroke is one of the major causes of death and disability worldwide, and an effective and timely treatment of ischemic stroke has been a challenge because of the narrow therapeutic window and the poor affinity with thrombus of the thrombolytic agent. In this study, rPZDCu, a multifunctional nanoparticle (NP) with the effects of thrombolysis, reactive oxygen species (ROS) scavenging, and neuroprotection, was synthesized based on an ultrasmall Cu4.6O NP, the thrombolytic agent rt-PA, and docosahexaenoic acid (DHA), which is a major component of the neuronal membrane. rPZDCu showed strong thrombus-targeting ability, which was achieved by the platelet cell membrane coating on the NP surface, and a good thrombolytic effect in both the common carotid artery clot model and embolic middle cerebral artery occlusion (MCAO) model of rats. Furthermore, rPZDCu exhibited a good escape from the phagocytosis of macrophages, effective promotion of the polarization of microglia, and efficient recovery of neurobiological and behavioral functions in the embolic MCAO model of rats. This is a heuristic report of (1) the Cu0/Cu+ NP for the treatments of brain diseases, (2) the integration of DHA and ROS scavengers for central nervous system therapies, and (3) diselenide-based ROS-responsive NPs for ischemic stroke treatments. This study also offers an example of cell membrane-camouflaged stimuli-responsive nanomedicine for brain-targeting drug delivery.
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Affiliation(s)
- Jianglong Kong
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China
| | - Rui Zou
- Department of Nuclear Medicine, the Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou 510630, People's Republic of China
| | - Runxuan Chu
- National Pharmaceutical Engineering Research Center, China State Institute of Pharmaceutical Industry, Shanghai 201203, People's Republic of China
| | - Nan Hu
- Changchun Institute of Technology, Changchun 130012, People's Republic of China
| | - Jiawen Liu
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China
| | - Yuting Sun
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China
| | - Xiaohan Ge
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China
| | - Meiru Mao
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China
| | - Hongrui Yu
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China
| | - Yi Wang
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China
- Ningbo Research Institute, Zhejiang University, Ningbo 315100, People's Republic of China
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Britten-Jones AC, Craig JP, Anderson AJ, Downie LE. Association between systemic omega-3 polyunsaturated fatty acid levels, and corneal nerve structure and function. Eye (Lond) 2022:10.1038/s41433-022-02259-0. [PMID: 36163491 DOI: 10.1038/s41433-022-02259-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 08/23/2022] [Accepted: 09/09/2022] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Omega-3 polyunsaturated fatty acids (PUFAs), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have anti-inflammatory and neuroprotective properties. This study sought to determine the relationship between corneal parameters and systemic omega-3 fatty acid levels. METHODS Forty-seven participants with no/mild peripheral neuropathy (26 with diabetes and 21 without) underwent comprehensive ocular surface and systemic PUFA assessments. Corneal anatomical parameters were assessed using in vivo confocal microscopy. Corneal sensitivity was measured using non-contact esthesiometry. Relationships between systemic PUFA levels and corneal parameters were evaluated with multiple linear regression, adjusted for age, sex, neuropathy symptom score, and presence of diabetes and dry eye disease. The relationship between corneal nerve fibre length (CNFL) and corneal sensitivity threshold was evaluated. RESULTS The median Omega-3 Index, a measure of erythrocyte EPA and DHA, was 5.21% (interquartile range: 4.44-5.94%) in the study population. Mean ( ± SD) CNFL was 13.53 ± 3.37 mm/mm2. Multiple linear regression showed that Omega-3 Index (β = 0.33; p = 0.02), age (β = -0.46; p = 0.001) and diabetes (β = -0.30; p = 0.03) were independently associated with CNFL (R2 = 0.39, p = 0.002). In a separate model, DHA (β = 0.32; p = 0.027) and age (β = -0.41; p = 0.003) were associated with CNFL (R2 = 0.37, p = 0.003). Neither systemic EPA nor omega-6 fatty acid levels correlated with CNFL. There was no association between PUFA levels and corneal sensitivity or corneal immune cell density. A negative correlation was found between CNFL and corneal sensation thresholds to a cooled stimulus in diabetes participants, in the central (ρ = -0.50; p = 0.009) and peripheral (ρ = -0.50; p = 0.01) cornea. CONCLUSIONS A positive relationship between the systemic Omega-3 Index and corneal nerve parameters suggests omega-3 PUFA intake may influence corneal nerve architecture.
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Affiliation(s)
| | - Jennifer P Craig
- Department of Ophthalmology, New Zealand National Eye Centre, The University of Auckland, Auckland, New Zealand
| | - Andrew J Anderson
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Australia
| | - Laura E Downie
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Australia.
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Petropoulos IN, Bitirgen G, Ferdousi M, Kalteniece A, Azmi S, D'Onofrio L, Lim SH, Ponirakis G, Khan A, Gad H, Mohammed I, Mohammadi YE, Malik A, Gosal D, Kobylecki C, Silverdale M, Soran H, Alam U, Malik RA. Corneal Confocal Microscopy to Image Small Nerve Fiber Degeneration: Ophthalmology Meets Neurology. FRONTIERS IN PAIN RESEARCH 2022; 2:725363. [PMID: 35295436 PMCID: PMC8915697 DOI: 10.3389/fpain.2021.725363] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 07/26/2021] [Indexed: 12/13/2022] Open
Abstract
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.
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Affiliation(s)
| | - Gulfidan Bitirgen
- Department of Ophthalmology, Meram Faculty of Medicine, Necmettin Erbakan University, Konya, Turkey
| | - Maryam Ferdousi
- Faculty of Biology, Medicine and Health, University of Manchester, Cardiovascular Trials Unit, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Alise Kalteniece
- Faculty of Biology, Medicine and Health, University of Manchester, Cardiovascular Trials Unit, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Shazli Azmi
- Faculty of Biology, Medicine and Health, University of Manchester, Cardiovascular Trials Unit, Manchester University NHS Foundation Trust, Manchester, United Kingdom.,Centre for Diabetes, Endocrinology and Metabolism, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Luca D'Onofrio
- Department of Experimental Medicine, Sapienza University, Rome, Italy
| | - Sze Hway Lim
- Department of Neurology, Salford Royal National Health System (NHS) Foundation Trust, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, United Kingdom
| | | | - Adnan Khan
- Department of Medicine, Weill Cornell Medicine-Qatar, Doha, Qatar
| | - Hoda Gad
- Department of Medicine, Weill Cornell Medicine-Qatar, Doha, Qatar
| | - Ibrahim Mohammed
- Department of Medicine, Weill Cornell Medicine-Qatar, Doha, Qatar
| | | | - Ayesha Malik
- Department of Medicine, Weill Cornell Medicine-Qatar, Doha, Qatar
| | - David Gosal
- Department of Neurology, Salford Royal National Health System (NHS) Foundation Trust, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, United Kingdom
| | - Christopher Kobylecki
- Department of Neurology, Salford Royal National Health System (NHS) Foundation Trust, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, United Kingdom
| | - Monty Silverdale
- Department of Neurology, Salford Royal National Health System (NHS) Foundation Trust, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, United Kingdom
| | - Handrean Soran
- Faculty of Biology, Medicine and Health, University of Manchester, Cardiovascular Trials Unit, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Uazman Alam
- Department of Cardiovascular and Metabolic Medicine, Clinical Sciences Centre, Pain Research Institute, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool University Hospital National Health System (NHS) Foundation Trust, Liverpool, United Kingdom
| | - Rayaz A Malik
- Department of Medicine, Weill Cornell Medicine-Qatar, Doha, Qatar.,Faculty of Biology, Medicine and Health, University of Manchester, Cardiovascular Trials Unit, Manchester University NHS Foundation Trust, Manchester, United Kingdom
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Zhou T, Lee A, Lo ACY, Kwok JSWJ. Diabetic Corneal Neuropathy: Pathogenic Mechanisms and Therapeutic Strategies. Front Pharmacol 2022; 13:816062. [PMID: 35281903 PMCID: PMC8905431 DOI: 10.3389/fphar.2022.816062] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 01/27/2022] [Indexed: 12/27/2022] Open
Abstract
Diabetes mellitus (DM) is a major global public health problem that can cause complications such as diabetic retinopathy, diabetic neuropathy, and diabetic nephropathy. Besides the reporting of reduction in corneal nerve density and decrease in corneal sensitivity in diabetic patients, there may be a subsequent result in delayed corneal wound healing and increased corneal infections. Despite being a potential cause of blindness, these corneal nerve changes have not gained enough attention. It has been proposed that corneal nerve changes may be an indicator for diabetic neuropathy, which can provide a window for early diagnosis and treatment. In this review, the authors aimed to give an overview of the relationship between corneal nerves and diabetic neuropathy as well as the underlying pathophysiological mechanisms of corneal nerve fiber changes caused by DM for improved prediction and prevention of diabetic neuropathy. In addition, the authors summarized current and novel therapeutic methods for delayed corneal wound healing, nerve protection and regeneration in the diabetic cornea.
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Affiliation(s)
- Ting Zhou
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Allie Lee
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Amy Cheuk Yin Lo
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Jeremy Sze Wai John Kwok
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
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Durán AM, Beeson WL, Firek A, Cordero-MacIntyre Z, De León M. Dietary Omega-3 Polyunsaturated Fatty-Acid Supplementation Upregulates Protective Cellular Pathways in Patients with Type 2 Diabetes Exhibiting Improvement in Painful Diabetic Neuropathy. Nutrients 2022; 14:nu14040761. [PMID: 35215418 PMCID: PMC8876723 DOI: 10.3390/nu14040761] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 02/04/2022] [Accepted: 02/08/2022] [Indexed: 12/12/2022] Open
Abstract
Background: Omega-3 polyunsaturated fatty acids (PUFAs) have been proposed to improve chronic neuroinflammatory diseases in peripheral and central nervous systems. For instance, docosahexaenoic acid (DHA) protects nerve cells from noxious stimuli in vitro and in vivo. Recent reports link PUFA supplementation to improving painful diabetic neuropathy (pDN) symptoms, but cellular mechanisms responsible for this therapeutic effect are not well understood. The objective of this study is to identify distinct cellular pathways elicited by dietary omega-3 PUFA supplementation in patients with type 2 diabetes mellitus (T2DM) affected by pDN. Methods: Forty volunteers diagnosed with type 2 diabetes were enrolled in the “En Balance-PLUS” diabetes education study. The volunteers participated in weekly lifestyle/nutrition education and daily supplementation with 1000 mg DHA and 200 mg eicosapentaenoic acid. The Short-Form McGill Pain Questionnaire validated clinical determination of baseline and post-intervention pain complaints. Laboratory and untargeted metabolomics analyses were conducted using blood plasma collected at baseline and after three months of participation in the dietary regimen. The metabolomics data were analyzed using random forest, hierarchical clustering, ingenuity pathway analysis, and metabolic pathway mapping. Results: The data show that metabolites involved in oxidative stress and glutathione production shifted significantly to a more anti-inflammatory state post supplementation. Example of these metabolites include cystathionine (+90%), S-methylmethionine (+9%), glycine cysteine-glutathione disulfide (+157%) cysteinylglycine (+19%), glutamate (−11%), glycine (+11%), and arginine (+13.4%). In addition, the levels of phospholipids associated with improved membrane fluidity such as linoleoyl-docosahexaenoyl-glycerol (18:2/22:6) (+253%) were significantly increased. Ingenuity pathway analysis suggested several key bio functions associated with omega-3 PUFA supplementation such as formation of reactive oxygen species (p = 4.38 × 10−4, z-score = −1.96), peroxidation of lipids (p = 2.24 × 10−5, z-score = −1.944), Ca2+ transport (p = 1.55 × 10−4, z-score = −1.969), excitation of neurons (p = 1.07 ×10−4, z-score = −1.091), and concentration of glutathione (p = 3.06 × 10−4, z-score = 1.974). Conclusion: The reduction of pro-inflammatory and oxidative stress pathways following dietary omega-3 PUFA supplementation is consistent with the promising role of these fatty acids in reducing adverse symptoms associated with neuroinflammatory diseases and painful neuropathy.
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Affiliation(s)
- Alfonso M. Durán
- Center for Health Disparities and Molecular Medicine, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA; (A.M.D.); (W.L.B.); (Z.C.-M.)
| | - W. Lawrence Beeson
- Center for Health Disparities and Molecular Medicine, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA; (A.M.D.); (W.L.B.); (Z.C.-M.)
- Center for Nutrition, Healthy Lifestyle and Disease Prevention, School of Public Health, Loma Linda University, Loma Linda, CA 92350, USA
| | - Anthony Firek
- Comparative Effectiveness and Clinical Outcomes Research Center, Riverside University Health System Medical Center, Moreno Valley, CA 92555, USA;
| | - Zaida Cordero-MacIntyre
- Center for Health Disparities and Molecular Medicine, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA; (A.M.D.); (W.L.B.); (Z.C.-M.)
- Center for Nutrition, Healthy Lifestyle and Disease Prevention, School of Public Health, Loma Linda University, Loma Linda, CA 92350, USA
| | - Marino De León
- Center for Health Disparities and Molecular Medicine, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA; (A.M.D.); (W.L.B.); (Z.C.-M.)
- Correspondence: ; Tel.: +1-909-558-9474
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8
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Ponirakis G, Abdul‐Ghani MA, Jayyousi A, Zirie MA, Al‐Mohannadi S, Almuhannadi H, Petropoulos IN, Khan A, Gad H, Migahid O, Megahed A, Qazi M, AlMarri F, Al‐Khayat F, Mahfoud Z, DeFronzo R, Malik RA. Insulin resistance limits corneal nerve regeneration in patients with type 2 diabetes undergoing intensive glycemic control. J Diabetes Investig 2021; 12:2002-2009. [PMID: 34002953 PMCID: PMC8565403 DOI: 10.1111/jdi.13582] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 03/22/2021] [Accepted: 04/15/2021] [Indexed: 01/04/2023] Open
Abstract
AIMS/INTRODUCTION This study aimed to investigate whether insulin resistance (IR) in individuals with type 2 diabetes undergoing intensive glycemic control determines the extent of improvement in neuropathy. MATERIALS AND METHODS This was an exploratory substudy of an open-label, randomized controlled trial of individuals with poorly controlled type 2 diabetes treated with exenatide and pioglitazone or insulin to achieve a glycated hemoglobin <7.0% (<53 mmol/mol). Baseline IR was defined using homeostasis model assessment of IR, and change in neuropathy was assessed using corneal confocal microscopy. RESULTS A total of 38 individuals with type 2 diabetes aged 50.2 ± 8.5 years with (n = 25, 66%) and without (n = 13, 34%) IR were studied. There was a significant decrease in glycated hemoglobin (P < 0.0001), diastolic blood pressure (P < 0.0001), total cholesterol (P < 0.01) and low-density lipoprotein (P = 0.05), and an increase in bodyweight (P < 0.0001) with treatment. Individuals with homeostasis model assessment of IR <1.9 showed a significant increase in corneal nerve fiber density (P ≤ 0.01), length (P ≤ 0.01) and branch density (P ≤ 0.01), whereas individuals with homeostasis model assessment of IR ≥1.9 showed no change. IR was negatively associated with change in corneal nerve fiber density after adjusting for change in bodyweight (P < 0.05). CONCLUSIONS Nerve regeneration might be limited in individuals with type 2 diabetes and IR undergoing treatment with pioglitazone plus exenatide or insulin to improve glycemic control.
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Affiliation(s)
- Georgios Ponirakis
- Weill Cornell Medicine in QatarQatar FoundationEducation City, DohaQatar
- Faculty of Science and EngineeringManchester Metropolitan UniversityManchesterUK
| | - Muhammad A Abdul‐Ghani
- National Diabetes CenterHamad General HospitalHamad Medical CorporationDohaQatar
- Division of DiabetesUniversity of Texas Health Science CenterSan AntonioTexasUSA
| | - Amin Jayyousi
- National Diabetes CenterHamad General HospitalHamad Medical CorporationDohaQatar
| | - Mahmoud A Zirie
- National Diabetes CenterHamad General HospitalHamad Medical CorporationDohaQatar
| | - Salma Al‐Mohannadi
- Weill Cornell Medicine in QatarQatar FoundationEducation City, DohaQatar
| | - Hamad Almuhannadi
- Weill Cornell Medicine in QatarQatar FoundationEducation City, DohaQatar
| | | | - Adnan Khan
- Weill Cornell Medicine in QatarQatar FoundationEducation City, DohaQatar
| | - Hoda Gad
- Weill Cornell Medicine in QatarQatar FoundationEducation City, DohaQatar
| | - Osama Migahid
- National Diabetes CenterHamad General HospitalHamad Medical CorporationDohaQatar
- Division of DiabetesUniversity of Texas Health Science CenterSan AntonioTexasUSA
| | - Ayman Megahed
- National Diabetes CenterHamad General HospitalHamad Medical CorporationDohaQatar
| | - Murtaza Qazi
- Weill Cornell Medicine in QatarQatar FoundationEducation City, DohaQatar
| | - Fatema AlMarri
- Weill Cornell Medicine in QatarQatar FoundationEducation City, DohaQatar
| | - Fatima Al‐Khayat
- Weill Cornell Medicine in QatarQatar FoundationEducation City, DohaQatar
| | - Ziyad Mahfoud
- Weill Cornell Medicine in QatarQatar FoundationEducation City, DohaQatar
| | - Ralph DeFronzo
- Division of DiabetesUniversity of Texas Health Science CenterSan AntonioTexasUSA
| | - Rayaz A Malik
- Weill Cornell Medicine in QatarQatar FoundationEducation City, DohaQatar
- Faculty of Science and EngineeringManchester Metropolitan UniversityManchesterUK
- National Diabetes CenterHamad General HospitalHamad Medical CorporationDohaQatar
- Institute of Cardiovascular ScienceUniversity of ManchesterManchesterUK
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9
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Britten-Jones AC, Kamel JT, Roberts LJ, Braat S, Craig JP, MacIsaac RJ, Downie LE. Investigating the Neuroprotective Effect of Oral Omega-3 Fatty Acid Supplementation in Type 1 Diabetes (nPROOFS1): A Randomized Placebo-Controlled Trial. Diabetes 2021; 70:1794-1806. [PMID: 33952620 DOI: 10.2337/db21-0136] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 04/29/2021] [Indexed: 11/13/2022]
Abstract
This randomized, double-masked, placebo-controlled trial evaluated the effects of oral omega-3 (n-3) fatty acid supplementation on peripheral nerves in type 1 diabetes. Participants with type 1 diabetes were assigned (1:1) to n-3 (1,800 mg/day fish oil) or placebo (600 mg/day olive oil) supplements for 180 days. The primary outcome was change from baseline in central corneal nerve fiber length (CNFL) at day 180. Secondary outcomes included change in other corneal nerve parameters, corneal sensitivity, peripheral small and large nerve fiber function, and ocular surface measures. Efficacy was analyzed according to the intention-to-treat principle. Safety assessments included diabetic retinopathy grade and adverse events. Between July 2017 and September 2019, 43 participants received n-3 (n = 21) or placebo (n = 22) supplements. All participants, except for two assigned to placebo, completed the trial. At day 180, the estimated increase in CNFL in the n-3 group, compared with placebo, was 2.70 mm/mm2 (95% CI 1.64, 3.75). The Omega-3 Index increased relative to placebo (3.3% [95% CI 2.4, 4.2]). There were no differences in most small or large nerve fiber functional parameters. Adverse events were similar between groups. In conclusion, we found in this randomized controlled trial that long-chain n-3 supplements impart corneal neuroregenerative effects in type 1 diabetes, indicating a role in modulating peripheral nerve health.
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Affiliation(s)
| | - Jordan T Kamel
- Department of Medicine, University of Melbourne, Fitzroy, Australia
- Centre for Clinical Neurosciences and Neurological Research, St. Vincent's Hospital Melbourne, Fitzroy, Australia
| | - Leslie J Roberts
- Department of Medicine, University of Melbourne, Fitzroy, Australia
- Centre for Clinical Neurosciences and Neurological Research, St. Vincent's Hospital Melbourne, Fitzroy, Australia
| | - Sabine Braat
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Parkville, Australia
- Methods and Implementation Support for Clinical Health research platform, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, Australia
| | - Jennifer P Craig
- Department of Ophthalmology, New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand
| | - Richard J MacIsaac
- Department of Medicine, University of Melbourne, Fitzroy, Australia
- Department of Endocrinology and Diabetes, St. Vincent's Hospital Melbourne, Fitzroy, Australia
| | - Laura E Downie
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Australia
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10
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Petropoulos IN, Ponirakis G, Ferdousi M, Azmi S, Kalteniece A, Khan A, Gad H, Bashir B, Marshall A, Boulton AJM, Soran H, Malik RA. Corneal Confocal Microscopy: A Biomarker for Diabetic Peripheral Neuropathy. Clin Ther 2021; 43:1457-1475. [PMID: 33965237 DOI: 10.1016/j.clinthera.2021.04.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 04/05/2021] [Accepted: 04/08/2021] [Indexed: 02/08/2023]
Abstract
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.
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Affiliation(s)
| | | | - Maryam Ferdousi
- Faculty of Biology, Medicine and Health, University of Manchester, Cardiovascular Trials Unit, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Shazli Azmi
- Faculty of Biology, Medicine and Health, University of Manchester, Cardiovascular Trials Unit, Manchester University NHS Foundation Trust, Manchester, United Kingdom; Centre for Diabetes, Endocrinology and Metabolism, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Alise Kalteniece
- Faculty of Biology, Medicine and Health, University of Manchester, Cardiovascular Trials Unit, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Adnan Khan
- Research Division, Weill Cornell Medicine-Qatar, Doha, Qatar
| | - Hoda Gad
- Research Division, Weill Cornell Medicine-Qatar, Doha, Qatar
| | - Bilal Bashir
- Centre for Diabetes, Endocrinology and Metabolism, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Andrew Marshall
- Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom; Clinical Neurophysiology, The Walton Centre, Liverpool, United Kingdom; Division of Neuroscience and Experimental Psychology, Faculty of Medical and Human Sciences, University of Manchester, Manchester, United Kingdom
| | - Andrew J M Boulton
- Faculty of Biology, Medicine and Health, University of Manchester, Cardiovascular Trials Unit, Manchester University NHS Foundation Trust, Manchester, United Kingdom; Centre for Diabetes, Endocrinology and Metabolism, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Handrean Soran
- Faculty of Biology, Medicine and Health, University of Manchester, Cardiovascular Trials Unit, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Rayaz A Malik
- Research Division, Weill Cornell Medicine-Qatar, Doha, Qatar; Faculty of Biology, Medicine and Health, University of Manchester, Cardiovascular Trials Unit, Manchester University NHS Foundation Trust, Manchester, United Kingdom.
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