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Zhang Y, Zhang Y, Miao R, Fang X, Yin R, Guan H, Tian J. The MTHFR C677T/A1298C polymorphism is associated with increased risk of microangiopathy in type 2 diabetes mellitus: A systematic review and meta-analysis. Nutr Res 2024; 130:34-47. [PMID: 39340999 DOI: 10.1016/j.nutres.2024.08.004] [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: 03/11/2024] [Revised: 08/30/2024] [Accepted: 08/30/2024] [Indexed: 09/30/2024]
Abstract
Extensive case-control association studies have been conducted over the past few decades to investigate the relationship between MTHFR polymorphism and type 2 diabetes mellitus (T2DM) microangiopathy. However, the strength of the evidence and clinical significance are unclear. Consequently, a meta-analysis was performed to examine the correlations between two prevalent MTHFR single nucleotide polymorphisms, MTHFR C677T and A1298C, and T2DM microangiopathy. Randomized controlled trials were systematically searched in PubMed, Cochrane, Embase, Web of Science, CNKI, VIP database, China Biology Medicine, and Wanfang until August 2023. A total of 42 studies were included. Random-effect models were utilized to estimate odds ratios (ORs) with 95% confidence intervals (CIs) to assess the association between MTHFR polymorphisms and T2DM microangiopathy susceptibility. T2DM microangiopathy was significantly associated with the MTHFR C677T polymorphism in the overall population (T vs C, OR = 1.43, 95% CI = 1.25-1.64; TT + CT vs CC: OR = 1.56, 95% CI = 1.30-1.88; TT vs CT + CC: OR = 1.66, 95% CI = 1.38-1.99; TT vs CC: OR = 2.03, 95% CI = 1.58-2.60). Additionally, the dominant model revealed that the MTHFR A1298C polymorphism was associated with T2DM microangiopathy (OR = 1.27, 95% CI: 1.09-1.47). This meta-analysis revealed that MTHFR may be involved in the pathogenesis of T2DM microangiopathy, providing a reference for early diagnosis and treatment of T2DM.
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Affiliation(s)
- Yuxin Zhang
- Institute of Metabolic Diseases, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China.
| | - Yanjiao Zhang
- Institute of Metabolic Diseases, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Runyu Miao
- Institute of Metabolic Diseases, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China; Graduate College, Beijing University of Chinese Medicine, Beijing, China
| | - Xinyi Fang
- Institute of Metabolic Diseases, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China; Graduate College, Beijing University of Chinese Medicine, Beijing, China
| | - Ruiyang Yin
- Institute of Metabolic Diseases, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Huifang Guan
- College of Traditional Chinese Medicine, Changchun University of Chinese Medicine, Changchun, China
| | - Jiaxing Tian
- Institute of Metabolic Diseases, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China.
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Wang X, Lan L. MTHFR C667T polymorphism and diabetic nephropathy susceptibility in patients with type 2 diabetes mellitus: An updated meta-analysis. Pteridines 2022. [DOI: 10.1515/pteridines-2022-0039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
Background
Numerous studies indicated that there exists a relationship between methylenetetrahydrofolate reductase (MTHFR) C667T polymorphism and diabetic nephropathy (DN) susceptibility; nonetheless, available proof reported from individual studies has not been consistent, so we performed an updated meta-analysis to evaluate the relationship between MTHFR C667T variant and DN.
Materials and methods
Relevant studies published before February 2022 were searched from the electronic databases PubMed, Embase, Scopus, Chinese Biology Medicine and the Chinese National Knowledge Infrastructure. The strength of the association was examined by odds ratio (OR) with 95% confidence interval (CI).
Results
The findings illustrated that there was a significant relationship between the polymorphism of C677T and DN compared with that to DM controls in allele (OR = 1.59, 95% CI = 1.39–1.82), dominant (OR = 1.76, 95% CI = 1.47–2.11) and recessive (OR = 1.85, 95% CI = 1.56–2.20) models in all populations. Moreover, as compared with the healthy controls, a significant relationship between C677T and DN was found in three genetic comparison models (allele: OR = 1.81, 95% CI = 1.43–2.29; dominant: OR = 2.09, 95% CI = 1.54–2.85; recessive: OR = 2.02, 95% CI = 1.51–2.70). Furthermore, stratifying data by race, diabetes duration and whether in Hardy–Weinberg equilibrium revealed substantially augmented vulnerability to DN in all subgroups.
Conclusion
The current meta-analysis highlighted conclusive results for the robust association between C677T polymorphisms and DN susceptibility.
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Affiliation(s)
- Xiaodong Wang
- Department of Rheumatology and Immunology, Lishui People’s Hospital , Zhejiang Province 323000 , PR China
| | - Lejian Lan
- Department Nephrology, Lishui People’s Hospital , No. 15 Dazhong Road Liandu District , Lishui City , Zhejiang Province 323000 , PR China
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Pathak D, Shrivastav D, Verma AK, Alsayegh AA, Yadav P, Khan NH, Al-Harbi AI, Khan MI, Bihade K, Singh DD, Beg MMA. Role of metabolizing MTHFR gene polymorphism (rs1801133) and its mRNA expression among Type 2 Diabetes. J Diabetes Metab Disord 2022; 21:511-516. [PMID: 35673506 PMCID: PMC9167251 DOI: 10.1007/s40200-022-01001-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Accepted: 01/30/2022] [Indexed: 10/19/2022]
Abstract
Objective Type 2 Diabetes is a glucose metabolic disorder occurred by insulin insensitivity in which folate metabolism plays an important role. it is believed that polymorphism of Methylenetetrahydrofolate reductase (MTHFR) C677T linked with type 2 diabetes mellitus. However, results are conflicted. therefore, in this study we re-examine the relationship between MTHFR C677T in type 2 diabetes mellitus patients. Methods Present research work included 100 newly diagnosed type 2 diabetic mellitus (T2DM) cases and 100 healthy individuals. After the blood sample collection all the biochemical parameters were evaluated among the T2DM cases and healthy individuals. DNA and RNA extraction from whole blood was done to study the MTHFR gene polymorphism by allele specific polymerase chain reaction method and its expression analysis was done by quantitative real time polymerase chain reaction method. Results The significant difference was observed in genotype distribution among case and control group (p=0.0002). Compared with wildtype CC genotype, CT heterozygous (OR=2.95, 95% Cl=1.62-5.38) and TT homozygous (OR=3.20, CI=1.79-5.73) suggest to have effect of MTHFR polymorphism on type 2 mellitus risk. Moreover, relative MTHFR mRNA expression was found for wild type CC genotype 3.02-fold, CT heterozygous genotype 2.57 fold and mutant TT homozygous genotype 0.50-fold which is down regulated (p<0.0001). Conclusion Our results indicates that the polymorphism in MTHFR C677T plays significant role in type II diabetes risk. MTHFR CT heterozygous and mutant TT genotype showed reduced mRNA expression among the T2DM patients. However, large scale case-control studies are needed to strengthen such conclusion in the future.
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Affiliation(s)
- Divya Pathak
- Central Drugs Standard Control Organisation, New Delhi, India
| | | | - Amit K. Verma
- Department of Zoology and Environmental Sciences, GKV, Haridwar, India
| | - Abdulrahman A. Alsayegh
- Department of Clinical Nutrition, College of Applied Medical Sciences, Jazan University, Jazan, Saudi Arabia
| | - Prasant Yadav
- Department of Biochemistry, All India Institute of Medical Sciences, Bhopal, Madhya Pradesh India
| | | | - Alhanouf I. Al-Harbi
- Department of Medical Laboratory, College of Applied Medical Sciences, Taibah University, Yanbu, Saudi Arabia
| | - Mohammad Idreesh Khan
- Department of Clinical Nutrition, College of Applied Health Sciences in Arras, Qassim University, Buraydah, Saudi Arabia
| | - Kapil Bihade
- Department of Accident and Emergency, Lok Nayak Hospital, New Delhi, India
| | - Desh Deepak Singh
- Amity Institute of Biotechnology, Amity University, Rajasthan Jaipur, India
| | - Mirza Masroor Ali Beg
- Faculty of Medicine, Alatoo International University, Bishkek, Kyrgyzstan
- Centre for promotion of Medical Research, Alatoo International University, Bishkek, Kyrgyzstan
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Diabetic Retinopathy: Mitochondria Caught in a Muddle of Homocysteine. J Clin Med 2020; 9:jcm9093019. [PMID: 32961662 PMCID: PMC7564979 DOI: 10.3390/jcm9093019] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 09/09/2020] [Accepted: 09/17/2020] [Indexed: 12/17/2022] Open
Abstract
Diabetic retinopathy is one of the most feared complications of diabetes. In addition to the severity of hyperglycemia, systemic factors also play an important role in its development. Another risk factor in the development of diabetic retinopathy is elevated levels of homocysteine, a non-protein amino acid, and hyperglycemia and homocysteine are shown to produce synergistic detrimental effects on the vasculature. Hyperhomocysteinemia is associated with increased oxidative stress, and in the pathogenesis of diabetic retinopathy, oxidative stress-mitochondrial dysfunction precedes the development of histopathology characteristic of diabetic retinopathy. Furthermore, homocysteine biosynthesis from methionine forms S-adenosyl methionine (SAM), and SAM is a co-substrate of DNA methylation. In diabetes, DNA methylation machinery is activated, and mitochondrial DNA (mtDNA) and several genes associated with mitochondrial homeostasis undergo epigenetic modifications. Consequently, high homocysteine, by further affecting methylation of mtDNA and that of genes associated with mtDNA damage and biogenesis, does not give any break to the already damaged mitochondria, and the vicious cycle of free radicals continues. Thus, supplementation of sensible glycemic control with therapies targeting hyperhomocysteinemia could be valuable for diabetic patients to prevent/slow down the development of this sight-threatening disease.
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Shi C, Wang P, Airen S, Brown C, Liu Z, Townsend JH, Wang J, Jiang H. Nutritional and medical food therapies for diabetic retinopathy. EYE AND VISION (LONDON, ENGLAND) 2020; 7:33. [PMID: 32582807 PMCID: PMC7310218 DOI: 10.1186/s40662-020-00199-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 05/28/2020] [Indexed: 02/07/2023]
Abstract
Diabetic retinopathy (DR) is a form of microangiopathy. Reducing oxidative stress in the mitochondria and cell membranes decreases ischemic injury and end-organ damage to the retina. New approaches are needed, which reduce the risk and improve the outcomes of DR while complementing current therapeutic approaches. Homocysteine (Hcy) elevation and oxidative stress are potential therapeutic targets in DR. Common genetic polymorphisms such as those of methylenetetrahydrofolate reductase (MTHFR), increase Hcy and DR risk and severity. Patients with DR have high incidences of deficiencies of crucial vitamins, minerals, and related compounds, which also lead to elevation of Hcy and oxidative stress. Addressing the effects of the MTHFR polymorphism and addressing comorbid deficiencies and insufficiencies reduce the impact and severity of the disease. This approach provides safe and simple strategies that support conventional care and improve outcomes. Suboptimal vitamin co-factor availability also impairs the release of neurotrophic and neuroprotective growth factors. Collectively, this accounts for variability in presentation and response of DR to conventional therapy. Fortunately, there are straightforward recommendations for addressing these issues and supporting traditional treatment plans. We have reviewed the literature for nutritional interventions that support conventional therapies to reduce disease risk and severity. Optimal combinations of vitamins B1, B2, B6, L-methylfolate, methylcobalamin (B12), C, D, natural vitamin E complex, lutein, zeaxanthin, alpha-lipoic acid, and n-acetylcysteine are identified for protecting the retina and choroid. Certain medical foods have been successfully used as therapy for retinopathy. Recommendations based on this review and our clinical experience are developed for clinicians to use to support conventional therapy for DR. DR from both type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) have similar retinal findings and responses to nutritional therapies.
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Affiliation(s)
- Ce Shi
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Peng Wang
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Shriya Airen
- College of Arts and Sciences, University of Miami, Miami, FL USA
| | - Craig Brown
- Department of Ophthalmology, College of Medicine, the University of Arkansas for Medical Sciences, Fayetteville, AR USA
| | - Zhiping Liu
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
- Ophthalmic Center, the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong China
| | - Justin H. Townsend
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
| | - Jianhua Wang
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
| | - Hong Jiang
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL USA
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Xu WH, Zhuang Y, Han X, Yuan ZL. Methylenetetrahydrofolate reductase C677T polymorphism and diabetic retinopathy risk: a meta-analysis of the Chinese population. J Int Med Res 2020; 48:300060518816834. [PMID: 30628508 PMCID: PMC7140216 DOI: 10.1177/0300060518816834] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Accepted: 11/12/2018] [Indexed: 11/16/2022] Open
Abstract
Objectives This study evaluated associations between methylenetetrahydrofolate reductase (MTHFR ) C677T polymorphisms and diabetic retinopathy (DR) susceptibility within the Chinese population. Methods Five databases (PubMed, EMBASE, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure) were used for literature searches of open access articles from inception through April 2017. Results Eight publications were identified involving 600 DR cases, 363 healthy controls, and 646 nondiabetic retinopathy (NDR) controls. There was a positive association between MTHFR C677T polymorphisms and DR risk within the Chinese population (DR with NDR controls: T vs. C, odds ratio (OR): 2.14, 95% confidence interval (CI): 1.55–2.97; TT vs. CC, OR: 4.19, 95% CI: 2.09–8.41; TT + CT vs. CC, OR: 2.83, 95% CI: 1.86–4.40; TT vs. CC + CT, OR: 2.48, 95% CI: 1.52–4.05. DR with healthy controls: T vs. C, OR: 2.48, 95% CI: 1.99–3.09; TT vs. CC, OR: 4.92, 95% CI: 3.18–7.62; TT + CT vs. CC, OR: 3.22, 95% CI: 2.32–4.48; TT vs. CC + CT, OR: 3.11, 95% CI: 1.83–5.28). The association was similar in South China and North China, when stratifying by geographic areas. Conclusion MTHFR C677T polymorphisms increase DR risk within the Chinese population.
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Affiliation(s)
- Wei-hai Xu
- Department of Ophthalmology, the First Affiliated Hospital of
Nanjing Medical University, Nanjing, Jiangsu Province, China
- Department of Ophthalmology, Binhai County People’s Hospital,
Yancheng, Jiangsu Province, China
| | - Ying Zhuang
- Department of Ophthalmology, Binhai County People’s Hospital,
Yancheng, Jiangsu Province, China
| | - Xiao Han
- Department of Biochemistry and Molecular Biology, Key Laboratory
of Human Functional Genomics of Jiangsu Province, Nanjing Medical University,
Nanjing, Jiangsu, China
| | - Zhi-lan Yuan
- Department of Ophthalmology, the First Affiliated Hospital of
Nanjing Medical University, Nanjing, Jiangsu Province, China
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Wang J, Brown C, Shi C, Townsend J, Gameiro GR, Wang P, Jiang H. Improving diabetic and hypertensive retinopathy with a medical food containing L-methylfolate: a preliminary report. EYE AND VISION 2019; 6:21. [PMID: 31363484 PMCID: PMC6643316 DOI: 10.1186/s40662-019-0147-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 07/01/2019] [Indexed: 02/07/2023]
Abstract
Background Homocysteine and vitamin D may play a role in the development of diabetic and hypertensive retinopathy in patients with diabetes mellitus (DM) and hypertension. Supplementing food with L-methylfolate and vitamin D theoretically may improve diabetic and hypertensive retinopathy, however, the outcome of these nutritional approaches has not been fully examined. A retrospective case review was done of cases of retinopathy reversal in patients on Ocufolin™ and a similar nonprescription multivitamin, Eyefolate™. In this study, they were administered L-methylfolate (2.7 mg and 3.0 mg, respectively) and vitamin D3 (4500 IU each). These dosages are significantly above the RDA but well below levels associated with toxicity. Case presentation Seven patients had nonproliferative diabetic retinopathy (NPDR) and some of them had hypertension. One patient had only hypertensive retinopathy. All patients were instructed to take Ocufolin™ medical food as a food supplement. Baseline genetic testing for MTHFR polymorphisms was conducted. Fundus photography was used to document the fundus condition of the enrolled eyes in 8 NPDR patients at the initial and follow-up visits. Microaneurysms (MA) and exudates were observed to be improved in some trial patients. All subjects had one or more MTHFR polymorphisms. All had diabetic retinopathy, hypertensive retinopathy, or both. MAs were resolved, and exudates were decreased in 8/8 cases after taking the medical food. Retinal edema was found in 2/8 cases and improved or resolved in both cases after taking the medical food or the supplement. The best corrected visual activity was stable or improved in 8/8 cases. Conclusion We report a series of diabetic and hypertensive retinopathy cases with MTHFR polymorphisms and the improvement of retinal microvasculature (mainly MAs) in serial fundus photography after taking a medical food or supplement containing L-methylfolate and vitamin D. It appears that the use of nutritional supplements and medical foods containing L-methylfolate and vitamin D may be effective in facilitating the improvement of diabetic and hypertensive retinopathy.
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Affiliation(s)
- Jianhua Wang
- 1Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
| | - Craig Brown
- 2Department of Ophthalmology, College of Medicine, University of Arkansas for Medical Sciences, Fayetteville, AR USA
| | - Ce Shi
- 1Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA.,3School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang China
| | - Justin Townsend
- 1Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
| | - Giovana Rosa Gameiro
- 1Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
| | - Peng Wang
- 1Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA.,Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Hong Jiang
- 1Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
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Garcia-Hernandez SC, Porchia LM, López-Bayghen E, Gonzalez-Mejia ME. The A1298C methylenetetrahydrofolate reductase polymorphism augments the risk of developing of diabetic retinopathy: A meta-analysis. Meta Gene 2019. [DOI: 10.1016/j.mgene.2019.100560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Mottaghi T, Khorvash F, Maracy M, Bellissimo N, Askari G. Effect of folic acid supplementation on nerve conduction velocity in diabetic polyneuropathy patients. Neurol Res 2019; 41:364-368. [PMID: 30730785 DOI: 10.1080/01616412.2019.1565180] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVES In diabetic polyneuropathy (DPN) patients, the effect of folic acid and homocysteine has been related to components of nerve conduction velocity (NCV). The objective of this study was to determine the effect of folic acid supplementation on NCV in DPN patients. METHODS Patients were randomized to receive either 1 mg of folic acid (n = 40) or placebo (n = 40) for 16 weeks. Blood samples were collected to assess serum folic acid and homocysteine concentrations, and NCV was performed for assessment of diabetic neuropathy. RESULTS At 16 weeks, in the supplemented group, serum levels of folic acid (p < 0.001) increased, homocysteine concentrations decreased (p < 0.001), with no change in serum vitamin B12 levels. There was a significant increase in sensory sural amplitude (p < 0.001), and components of motor nerves, including amplitude (p = 0.001) and velocity (p < 0.001), but decreased onset latency of peroneal (p = 0.019) and tibial (p = 0.011) motor nerves. CONCLUSION Our data suggest that supplementation with 1 mg of folic acid for 16 weeks may be useful for enhancing NCV in DPN patients.
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Affiliation(s)
- Tayebeh Mottaghi
- a Food Security Research Center , Isfahan University of Medical Sciences , Isfahan , Iran.,e Department of Community Nutrition, School of Nutrition and Food Science , Isfahan University of Medical Sciences , Isfahan , Iran
| | - Fariborz Khorvash
- b Department of Neurology , Isfahan University of Medical Sciences , Isfahan , Iran
| | - Mohammadreza Maracy
- c Departments of Epidemiology and Biostatistics, School of Health , Isfahan University of Medical Sciences , Isfahan , Iran
| | - Nick Bellissimo
- d School of Nutrition , Ryerson University , Toronto , Ontario , Canada
| | - Gholamreza Askari
- a Food Security Research Center , Isfahan University of Medical Sciences , Isfahan , Iran.,e Department of Community Nutrition, School of Nutrition and Food Science , Isfahan University of Medical Sciences , Isfahan , Iran
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Santana Bezerra H, Severo de Assis C, dos Santos Nunes MK, Wanderley de Queiroga Evangelista I, Modesto Filho J, Alves Pegado Gomes CN, Ferreira do Nascimento RA, Pordeus Luna RC, de Carvalho Costa MJ, de Oliveira NFP, Camati Persuhn D. The MTHFR promoter hypermethylation pattern associated with the A1298C polymorphism influences lipid parameters and glycemic control in diabetic patients. Diabetol Metab Syndr 2019; 11:4. [PMID: 30675189 PMCID: PMC6334445 DOI: 10.1186/s13098-019-0399-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 01/02/2019] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Polymorphisms in the gene encoding methylenetetrahydrofolate reductase (MTHFR) have been investigated as risk factors for microvascular complications of diabetes; however, simultaneous analysis of these polymorphisms and the methylation pattern of the gene has never been conducted. The objective of the present study was to evaluate the simultaneous relationship between MTHFR methylation and MTHFR C6TT7 and A1298C polymorphisms with metabolic, inflammatory and oxidative stress parameters related to microvascular complications, diabetic retinopathy (DR) and diabetic nephropathy (DN) in diabetic patients. METHODS A total of 107 patients who were diagnosed in the previous 5 to 10 years were recruited and divided into groups with complications (DR and/or DN) or without complications. Methylation analysis of the gene promoter was conducted using the MSP technique, and analysis of the A1298C and C677T polymorphisms was conducted using the restriction fragment length polymorphism (RFLP) assay. Microalbuminuria was determined using urine samples, and other analytes of interest were determined in blood samples using commercial kits. The Mann-Whitney and Chi square statistical tests were used with significance considered at p < 0.05. RESULTS Subjects with a hypermethylated profile and the 1298AA genotype showed the highest levels of blood glucose (p = 0.03), total cholesterol (p = 0.0001) and LDL cholesterol (p = 0.0006). The same profile was associated with higher levels of HbA1c (p = 0.025), glycemia (p = 0.04) and total cholesterol (0.004) in the control group and total cholesterol (p = 0.005) and LDL cholesterol (p = 0.002) in the complications group. Serum creatinine was higher in subjects in the hypermethylated group with the genotype 677CC only in the control group (p = 0.0020). The methylated profile in presence of 677CC + 1298AA and the 677CT/TT +1298AA haplotypes showed higher levels of total cholesterol (p = 0.0024; 0.0031) and LDL cholesterol (p = 0.0060; 0.0125) than 1298AC/CC carriers. The fasting glycemia was higher in hypermethylated profile in the presence of 677CC/1298AA haplotype (p = 0.0077). CONCLUSION The hypermethylated methylation profile associated with the 1298AA genotype appeared to be connected to higher values of glycemia, total cholesterol and LDL cholesterol.
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Affiliation(s)
| | | | | | | | - João Modesto Filho
- Department of Internal Medicine, Federal University of Paraiba, Joao Pessoa, Brazil
| | | | | | | | - Maria José de Carvalho Costa
- Nutrition Science Department and Post-Graduate Program in Nutrition Science, Federal University of Paraiba, Joao Pessoa, Brazil
| | | | - Darlene Camati Persuhn
- Department of Molecular Biology and Post-Graduate Program in Nutrition Science, Federal University of Paraiba, João Pessoa, PB CEP 58051-900 Brazil
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11
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Luo Z, Lu Z, Muhammad I, Chen Y, Chen Q, Zhang J, Song Y. Associations of the MTHFR rs1801133 polymorphism with coronary artery disease and lipid levels: a systematic review and updated meta-analysis. Lipids Health Dis 2018; 17:191. [PMID: 30115070 PMCID: PMC6097444 DOI: 10.1186/s12944-018-0837-y] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Accepted: 07/31/2018] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND The associations of the 5,10-methylenetetrahydrofolate reductase gene (MTHFR) rs1801133 polymorphism with coronary artery disease (CAD) and plasma lipid levels have been widely investigated, but the results were inconsistent and inconclusive. This meta-analysis aimed to clarify the relationships of the rs1801133 polymorphism with CAD and plasma lipid levels. METHODS By searching in PubMed, Google Scholar, Web of Science, Cochrane Library, Wanfang, VIP and CNKI databases, 123 studies (87,020 subjects) and 65 studies (85,554 subjects) were identified for the CAD association analysis and the lipid association analysis, respectively. Odds ratio (OR) and standardized mean difference (SMD) were used to determine the effects of the rs1801133 polymorphism on CAD risk and lipid levels, respectively. RESULTS The variant T allele of the rs1801133 polymorphism was associated with increased risk of CAD under allelic model [OR = 1.11, 95% confidence interval (CI) = 1.06-1.17, P < 0.01], additive model (OR = 1.25, 95% CI = 1.14-1.37, P < 0.01), dominant model (OR = 1.11, 95% CI = 1.04-1.17, P < 0.01), and recessive model (OR = 1.22, 95% CI = 1.12-1.32, P < 0.01). The T carriers had higher levels of total cholesterol (TC) (SMD = 0.04, 95% CI = 0.01-0.07, P = 0.02) and low-density lipoprotein cholesterol (LDL-C) (SMD = 0.07, 95% CI = 0.01-0.12, P = 0.01) than the non-carriers. CONCLUSIONS The meta-analysis suggested that the T allele of the rs1801133 polymorphism is a risk factor for CAD, which is possibly and partly mediated by abnormal lipid levels.
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Affiliation(s)
- Zhi Luo
- Department of Cardiology, Affiliated Hospital of North Sichuan Medical College, Nanchong, 637000, People's Republic of China
| | - Zhan Lu
- Department of Cardiology, Affiliated Hospital of North Sichuan Medical College, Nanchong, 637000, People's Republic of China
| | - Irfan Muhammad
- Department of Cardiology, Affiliated Hospital of North Sichuan Medical College, Nanchong, 637000, People's Republic of China
| | - Yun Chen
- Department of Cardiology, Affiliated Hospital of North Sichuan Medical College, Nanchong, 637000, People's Republic of China
| | - Qiuhong Chen
- School of Clinical Medicine, North Sichuan Medical College, Nanchong, 637000, People's Republic of China
| | - Jiaojiao Zhang
- School of Clinical Medicine, North Sichuan Medical College, Nanchong, 637000, People's Republic of China
| | - Yongyan Song
- Department of Medical Biochemistry, School of Preclinical Medicine, North Sichuan Medical College, Nanchong, 637000, People's Republic of China.
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Ay A, Alkanli N, Sipahi T, Gulyasar T, Ustundag S, Guldiken S, Sut N. Investigation of the relationship between MTHFR, IRS and CALCA gene polymorphisms and development of diabetic nephropathy in patients with type 2 diabetes mellitus. BIOTECHNOL BIOTEC EQ 2018. [DOI: 10.1080/13102818.2018.1485514] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Affiliation(s)
- Arzu Ay
- Department of Biophysics, Faculty of Medicine, Trakya University, Edirne, Turkey
| | - Nevra Alkanli
- Department of Biophysics, Faculty of Medicine, T.C. Halic University, Istanbul, Turkey
| | - Tammam Sipahi
- Department of Biophysics, Faculty of Medicine, Trakya University, Edirne, Turkey
| | - Tevfik Gulyasar
- Department of Biophysics, Faculty of Medicine, Trakya University, Edirne, Turkey
| | - Sedat Ustundag
- Department of Internal Medicine (Nephrology), Faculty of Medicine, Trakya University, Edirne, Turkey
| | - Sibel Guldiken
- Department of Internal Medicine (Endocrinology and Metabolic Diseases), Faculty of Medicine, Trakya University, Edirne, Turkey
| | - Necdet Sut
- Department of Biostatistics and Medical Informatics, Faculty of Medicine, Trakya University, Edirne, Turkey
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13
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Broadgate S, Kiire C, Halford S, Chong V. Diabetic macular oedema: under-represented in the genetic analysis of diabetic retinopathy. Acta Ophthalmol 2018; 96 Suppl A111:1-51. [PMID: 29682912 DOI: 10.1111/aos.13678] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 11/21/2017] [Indexed: 12/15/2022]
Abstract
Diabetic retinopathy, a complication of both type 1 and type 2 diabetes, is a complex disease and is one of the leading causes of blindness in adults worldwide. It can be divided into distinct subclasses, one of which is diabetic macular oedema. Diabetic macular oedema can occur at any time in diabetic retinopathy and is the most common cause of vision loss in patients with type 2 diabetes. The purpose of this review is to summarize the large number of genetic association studies that have been performed in cohorts of patients with type 2 diabetes and published in English-language journals up to February 2017. Many of these studies have produced positive associations with gene polymorphisms and diabetic retinopathy. However, this review highlights that within this large body of work, studies specifically addressing a genetic association with diabetic macular oedema, although present, are vastly under-represented. We also highlight that many of the studies have small patient numbers and that meta-analyses often inappropriately combine patient data sets. We conclude that there will continue to be conflicting results and no meaningful findings will be achieved if the historical approach of combining all diabetic retinopathy disease states within patient cohorts continues in future studies. This review also identifies several genes that would be interesting to analyse in large, well-defined cohorts of patients with diabetic macular oedema in future candidate gene association studies.
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Affiliation(s)
- Suzanne Broadgate
- Nuffield Laboratory of Ophthalmology; Nuffield Department of Clinical Neurosciences; University of Oxford; Oxford UK
| | - Christine Kiire
- Nuffield Laboratory of Ophthalmology; Nuffield Department of Clinical Neurosciences; University of Oxford; Oxford UK
- Oxford Eye Hospital; John Radcliffe Hospital; Oxford University NHS Foundation Trust; Oxford UK
| | - Stephanie Halford
- Nuffield Laboratory of Ophthalmology; Nuffield Department of Clinical Neurosciences; University of Oxford; Oxford UK
| | - Victor Chong
- Nuffield Laboratory of Ophthalmology; Nuffield Department of Clinical Neurosciences; University of Oxford; Oxford UK
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Nithya K, Isabel W, Angeline T, Priscilla A, Shakila H, Asirvatham A. MTHFR C677T gene polymorphism in Type 2 diabetes mellitus patients with and without vascular complications: A case-control study. Meta Gene 2017. [DOI: 10.1016/j.mgene.2017.08.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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15
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Chen D, Wang J, Dan Z, Shen X, Ci D. The relationship between methylenetetrahydrofolate reductase C677T polymorphism and diabetic retinopathy: A meta-analysis in multiethnic groups. Ophthalmic Genet 2017; 39:200-207. [PMID: 29182429 DOI: 10.1080/13816810.2017.1401087] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Da Chen
- Department of Ophthalmology, Wuhan Hospital of Traditional Chinese Medicine, Wuhan, China
| | - Jihong Wang
- Department of Ophthalmology, Affiliated Wuxi Hospital of Nanjing China Traditional Chinese Medicine, Wuxi, China
| | - Zengrenqing Dan
- Department of Ophthalmology, Affiliated Wuxi Hospital of Nanjing China Traditional Chinese Medicine, Wuxi, China
| | - Xi Shen
- Department of Ophthalmology, Affiliated Wuxi Hospital of Nanjing China Traditional Chinese Medicine, Wuxi, China
| | - Danyangji Ci
- Department of Ophthalmology, Affiliated Wuxi Hospital of Nanjing China Traditional Chinese Medicine, Wuxi, China
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16
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Methylenetetrahydrofolate Reductase (MTHFR) (C677T and A1298C) Polymorphisms and Vascular Complications in Patients with Type 2 Diabetes. Can J Diabetes 2017; 41:366-371. [DOI: 10.1016/j.jcjd.2016.11.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Revised: 08/14/2016] [Accepted: 11/17/2016] [Indexed: 11/23/2022]
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17
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Luo S, Wang F, Shi C, Wu Z. A Meta-Analysis of Association between Methylenetetrahydrofolate Reductase Gene (MTHFR) 677C/T Polymorphism and Diabetic Retinopathy. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2016; 13:E806. [PMID: 27517946 PMCID: PMC4997492 DOI: 10.3390/ijerph13080806] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 07/21/2016] [Accepted: 07/29/2016] [Indexed: 01/31/2023]
Abstract
AIMS To shed light on the conflicting findings of the association between the methylenetetrahydrofolate reductase gene (MTHFR) 677C/T polymorphism and the risk of diabetic retinopathy (DR), a meta-analysis was conducted. METHODS A predefined search was performed on 1747 DR cases and 3146 controls from 18 published studies by searching electronic databases and reference lists of relevant articles. A random-effects or fixed-effects model was used to estimate the sizes of overall and stratification effects of the MTHFR 677C/T polymorphism on the risk of DR, as appropriate. RESULTS Risks were evaluated by odds ratios (OR) with 95% confidence intervals (95% CI). We found a significant association between the MTHFR 677C/T polymorphism and the risk of DR for each genetic model (recessive model: OR = 1.67; 95% CI: 1.19-2.40 and dominant model: OR = 1.71; 95% CI: 1.28-2.28; respectively). In stratified analysis; we further found that the Asian group with both types of diabetes mellitus (DM) showed a significant association with genetic models (recessive model: OR = 2.16; 95% CI: 1.75-2.60 and dominant model: OR = 1.98; 95% CI: 1.42-2.76; respectively). CONCLUSIONS Our study suggested that the MTHFR 677C/T polymorphism may contribute to DR development, especially in Asian populations. Prospective and additional genome-wide association studies (GWAS) are needed to clarify the real role of the MTHFR gene in determining susceptibility to DR.
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Affiliation(s)
- Shasha Luo
- Department of Ophthalmology, Nanjing Medical University Affiliated Wuxi Second Hospital, 68 Zhongshan Road, Wuxi 214002, China.
| | - Furu Wang
- Jiangsu Provincial Center for Disease Prevention and Control, 172 Jiangsu Road, Nanjing 210029, China.
| | - Chao Shi
- Wuxi Center for Disease Control and Prevention, 499 Jincheng Road, Wuxi 214023, China.
| | - Zhifeng Wu
- Department of Ophthalmology, Nanjing Medical University Affiliated Wuxi Second Hospital, 68 Zhongshan Road, Wuxi 214002, China.
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18
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Agarwal A, Ingham SA, Harkins KA, Do DV, Nguyen QD. The role of pharmacogenetics and advances in gene therapy in the treatment of diabetic retinopathy. Pharmacogenomics 2016; 17:309-20. [PMID: 26807609 DOI: 10.2217/pgs.15.173] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Diabetic retinopathy (DR) and its complications such as diabetic macular edema continue to remain a major cause for legal blindness in the developed world. While the introduction of anti-tVEGF agents has significantly improved visual outcomes of patients with DR, unpredictable response, largely due to genetic polymorphisms, appears to be a challenge with this therapy. With advances in identification of various genetic biomarkers, novel therapeutic strategies consisting of gene transfer are being developed and tested for patients with DR. Application of pharmacogenetic principles appears to be a promising futuristic strategy to attenuate diabetes-mediated retinal vasculopathy. In this comprehensive review, data from recent studies in the field of pharmacogenomics for the treatment of DR have been provided.
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Affiliation(s)
- Aniruddha Agarwal
- Ocular Imaging Research & Reading Center (OIRRC), Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, South 42nd Street & Emile St, Omaha, NE 68198, USA
| | - Sally A Ingham
- College of Medicine, University of Nebraska Medical Center, South 42nd Street & Emile St, Omaha, NE 68198, USA
| | - Keegan A Harkins
- Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, South 42nd Street & Emile St, Omaha, NE 68198, USA
| | - Diana V Do
- Ocular Imaging Research & Reading Center (OIRRC), Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, South 42nd Street & Emile St, Omaha, NE 68198, USA.,Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, South 42nd Street & Emile St, Omaha, NE 68198, USA
| | - Quan Dong Nguyen
- Ocular Imaging Research & Reading Center (OIRRC), Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, South 42nd Street & Emile St, Omaha, NE 68198, USA.,Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, South 42nd Street & Emile St, Omaha, NE 68198, USA
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19
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Zhou TB, Drummen GP, Jiang ZP, Li HY. Methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphism and diabetic nephropathy susceptibility in patients with type 2 diabetes mellitus. Ren Fail 2015; 37:1247-59. [PMID: 26161693 DOI: 10.3109/0886022x.2015.1064743] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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20
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Agarwal A, Soliman MK, Sepah YJ, Do DV, Nguyen QD. Diabetic retinopathy: variations in patient therapeutic outcomes and pharmacogenomics. PHARMACOGENOMICS & PERSONALIZED MEDICINE 2014; 7:399-409. [PMID: 25548526 PMCID: PMC4271791 DOI: 10.2147/pgpm.s52821] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Diabetes and its microvascular complications in patients poses a significant challenge and constitutes a major health problem. When it comes to manifestations in the eye, each case of diabetic retinopathy (DR) is unique, in terms of the phenotype, genotype, and, more importantly, the therapeutic response. It is therefore important to identify factors that distinguish one patient from another. Personalized therapy in DR is a new trend aimed at achieving maximum therapeutic response in patients by identifying genotypic and phenotypic factors that may result in less than optimal response to conventional therapy, and consequently, lead to poorer outcome. With advances in the identification of these genetic markers, such as gene polymorphisms and human leucocyte antigen associations, as well as development of drugs that can target their effects, the future of personalized medicine in DR is promising. In this comprehensive review, data from various studies have been analyzed to present what has been achieved in the field of pharmacogenomics thus far. An insight into future research is also provided.
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Affiliation(s)
- Aniruddha Agarwal
- Ocular Imaging Research and Reading Center, Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, USA
| | - Mohamed K Soliman
- Ocular Imaging Research and Reading Center, Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, USA
| | - Yasir J Sepah
- Ocular Imaging Research and Reading Center, Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, USA
| | - Diana V Do
- Ocular Imaging Research and Reading Center, Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, USA
| | - Quan Dong Nguyen
- Ocular Imaging Research and Reading Center, Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, USA
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21
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Zhang X, Zeng H, Bao S, Wang N, Gillies MC. Diabetic macular edema: new concepts in patho-physiology and treatment. Cell Biosci 2014; 4:27. [PMID: 24955234 PMCID: PMC4046142 DOI: 10.1186/2045-3701-4-27] [Citation(s) in RCA: 141] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 04/22/2014] [Indexed: 12/22/2022] Open
Abstract
Diabetic macular edema (DME), a serious eye complication caused primarily by hyperglycemia, is one of the major causes of blindness. DME, which is characterized by cystic retinal thickening or lipid deposition, is prone to relapse after successful treatment. DME is a complex pathological process caused by multiple factors, including breakdown of the inner and outer blood-retinal barriers, oxidative stress, and elevated levels of vascular endothelial growth factor which have been demonstrated in both preclinical and clinical studies. Starling's law theory explains many of the features of DME. Early detection and treatment of DME can prevent vision loss. Current effective interventions for DME include treatment of systemic risk factors, such as elevated blood glucose, blood pressure and dyslipidemia. Ophthalmic treatments include laser photocoagulation, surgery and intraocular pharmacotherapy. New drugs, which are given by intraocular injection, have emerged in recent years to become first line treatment for DME that affects the central macula with loss of vision. Laser photocoagulation is still the gold standard of treatment for DME which does not involve the central macular. This review outlines these new treatments with particular emphasis on the optimal timing of how they are given.
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Affiliation(s)
- Xinyuan Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Lab, Beijing 100730 PR China ; Macula Research Group, Save Sight Institute, The University of Sydney, Sydney, NSW, Australia
| | - Huan Zeng
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Lab, Beijing 100730 PR China
| | - Shian Bao
- Discipline of Pathology, School of Medical Sciences and Bosch Institute, The University of Sydney, Sydney, NSW 2006, Australia
| | - Ningli Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Lab, Beijing 100730 PR China
| | - Mark C Gillies
- Macula Research Group, Save Sight Institute, The University of Sydney, Sydney, NSW, Australia
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22
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Abstract
Multiple studies have shown that genetic factors may play an important role in determining an individual's risk for the development of diabetic retinopathy (DR) and progression to proliferative DR. However, consistent and definitive genetic associations with DR across broad populations have been not been established. Numerous genes have been studied for their association with DR and the results of these investigations have most specifically pointed to three specific genes that are likely involved in DR development and progression. The gene coding for vascular endothelial growth factor, aldose reductase, and the receptor for advanced glycation end products have been extensively evaluated, and specific polymorphisms of these genes have been suggested to potentially increase the risk of DR development. In this paper, we have reviewed the published literature on the genetics of DR and the potential implications for DR development and progression.
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Affiliation(s)
- Ahmed F Omar
- Joslin Diabetes Center, Beetham Eye Institute , Boston, Massachusetts , USA and
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23
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Settin A, El-Baz R, Ismaeel A, Tolba W, Allah WA. Association of ACE and MTHFR genetic polymorphisms with type 2 diabetes mellitus: Susceptibility and complications. J Renin Angiotensin Aldosterone Syst 2014; 16:838-43. [PMID: 24452036 DOI: 10.1177/1470320313516172] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
HYPOTHESIS/INTRODUCTION Polymorphisms of angiotensin converting enzyme (ACE) and methylene-tetrahydrofolate reductase (MTHFR) genes have been proposed to be associated with type 2 diabetes mellitus (T2DM) with conflicting results. This work was planned in order to check for the association of these polymorphisms with the susceptibility for and complications of T2DM among Egyptian cases. MATERIALS AND METHODS This is a case controlled study involving 203 patients with T2DM and 311 healthy controls. Polymorphic variants of ACE I>D and MTHFR (677 C>T and 1298 A>C) were determined using the polymerase chain reaction (PCR) restriction analysis technique. RESULTS The susceptibility to T2DM was higher among subjects having the MTHFR 677TT (odds ratio (OR)=2.2, p=0.01), MTHFR 1298 AA (OR=1.84, p=0.001) and ACE (ID+II) (OR=2.0, p=0.0007) genotypes. Logistic regression analysis showed that MTHFR 677T allele was a risk factor for diabetic retinopathy (DR) (OR=3.47, p<0.001), diabetic polyneuropathy (DPN) (OR=5.2, p<0.0001) and ischemic heart disease (IHD) (OR=2.9, p<0.05), while MTHFR 1298 C allele was a risk factor for DR (OR=4.2, p<0.001) and the ACE DD genotype was a risk factor for DPN (OR=3.1, p<0.001). CONCLUSIONS The MTHFR 677 TT genotype was associated with T2DM susceptibility and complications (DR, DPN and IHD). The MTHFR 1298 CC, AC and ACE DD genotypes were associated with DR and DPN.
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Affiliation(s)
| | | | | | - Wafaa Tolba
- Zoology Department, Mansoura University, Egypt
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24
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Kumar R, Sharma RK, Agarwal S. Genetic predisposition for development of nephropathy in type 2 diabetes mellitus. Biochem Genet 2013; 51:865-75. [PMID: 23846111 DOI: 10.1007/s10528-013-9613-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 02/25/2013] [Indexed: 10/26/2022]
Abstract
The aim of the study was to explore the association of the angiotensin-converting enzyme (ACE) gene I/D polymorphism and the methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism with development of diabetic nephropathy in type 2 diabetes mellitus. Three groups were recruited during 2007-2011: 232 normal controls, 185 type 2 diabetics without nephropathy, and 407 type 2 diabetics with nephropathy. The ACE I/D and MTHFR C677T polymorphisms were examined using PCR and PCR-RFLP methods. We found no significant association of the ACE I/D polymorphism with diabetic nephropathy in genotype, allele, dominant, and recessive models. We observed a significant association of MTHFR C677T with development of diabetic nephropathy in type 2 diabetics. The MTHFR C677T polymorphism plays a significant role in predisposition of renal insufficiency in diabetic patients.
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Affiliation(s)
- Ravindra Kumar
- Department of Genetics, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, 226014, Uttar Pradesh, India
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25
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Raison CL, Miller AH. The evolutionary significance of depression in Pathogen Host Defense (PATHOS-D). Mol Psychiatry 2013; 18:15-37. [PMID: 22290120 PMCID: PMC3532038 DOI: 10.1038/mp.2012.2] [Citation(s) in RCA: 159] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Revised: 11/21/2011] [Accepted: 01/03/2012] [Indexed: 12/24/2022]
Abstract
Given the manifold ways that depression impairs Darwinian fitness, the persistence in the human genome of risk alleles for the disorder remains a much debated mystery. Evolutionary theories that view depressive symptoms as adaptive fail to provide parsimonious explanations for why even mild depressive symptoms impair fitness-relevant social functioning, whereas theories that suggest that depression is maladaptive fail to account for the high prevalence of depression risk alleles in human populations. These limitations warrant novel explanations for the origin and persistence of depression risk alleles. Accordingly, studies on risk alleles for depression were identified using PubMed and Ovid MEDLINE to examine data supporting the hypothesis that risk alleles for depression originated and have been retained in the human genome because these alleles promote pathogen host defense, which includes an integrated suite of immunological and behavioral responses to infection. Depression risk alleles identified by both candidate gene and genome-wide association study (GWAS) methodologies were found to be regularly associated with immune responses to infection that were likely to enhance survival in the ancestral environment. Moreover, data support the role of specific depressive symptoms in pathogen host defense including hyperthermia, reduced bodily iron stores, conservation/withdrawal behavior, hypervigilance and anorexia. By shifting the adaptive context of depression risk alleles from relations with conspecifics to relations with the microbial world, the Pathogen Host Defense (PATHOS-D) hypothesis provides a novel explanation for how depression can be nonadaptive in the social realm, whereas its risk alleles are nonetheless represented at prevalence rates that bespeak an adaptive function.
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Affiliation(s)
- C L Raison
- Department of Psychiatry, College of Medicine, University of Arizona, Tucson, AZ 85724-5137, USA.
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26
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El-Baz R, Settin A, Ismaeel A, Khaleel AA, Abbas T, Tolba W, Abd Allah W, Sobh MAEK. MTHFR C677T, A1298C and ACE I/D polymorphisms as risk factors for diabetic nephropathy among type 2 diabetic patients. J Renin Angiotensin Aldosterone Syst 2012; 13:472-477. [DOI: 10.1177/1470320312444651] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/01/2023] Open
Affiliation(s)
| | | | - Azza Ismaeel
- Zoology Department, Faculty Of Science, Mansoura University, Egypt
| | | | - Tarek Abbas
- Urology and Nephrology Center, Mansoura University, Egypt
| | - Wafaa Tolba
- Zoology Department, Faculty Of Science, Mansoura University, Egypt
| | - Wafaa Abd Allah
- Zoology Department, Faculty Of Science, Mansoura University, Egypt
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27
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Wang H, Fan D, Hong T. Is the C677T polymorphism in methylenetetrahydrofolate reductase gene or plasma homocysteine a risk factor for diabetic peripheral neuropathy in Chinese individuals? Neural Regen Res 2012; 7:2384-91. [PMID: 25538764 PMCID: PMC4268745 DOI: 10.3969/j.issn.1673-5374.2012.30.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 09/03/2012] [Indexed: 12/02/2022] Open
Abstract
The present study enrolled 251 diabetic patients, including 101 with neuropathy and 150 without neuropathy. Of the 150 patients, 100 had no complications, such as retinopathy, nephropathy, or neuropathy. Polymerase chain reaction-restriction fragment length polymorphism analysis was used to identify methylenetetrahydrofolate reductase gene variants. Plasma homocysteine levels were also measured. Homocysteine levels and the frequency of hyperhomocysteinemia were significantly higher in patients with diabetic peripheral neuropathy compared with diabetic patients without neuropathy (P < 0.05). In logistic regression analysis with neuropathy as the dependent variable, the frequency of C677T in methylenetetrahydrofolate reductase was significantly higher in patients with diabetic peripheral neuropathy compared with patients without diabetic complications. Homocysteine levels were significantly higher in patients with diabetic peripheral neuropathy carrying the 677T allele and low folic acid levels. In conclusion, hyperhomocysteinemia is an independent risk factor for diabetic neuropathy in Chinese patients with diabetes. The C677T polymorphism in methylenetetrahydrofolate reductase and low folic acid levels may be risk factors for diabetic peripheral neuropathy in Chinese patients with diabetes.
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Affiliation(s)
- Hongli Wang
- Department of Neurology, Peking University Third Hospital, Beijing 100191, China
| | - Dongsheng Fan
- Department of Neurology, Peking University Third Hospital, Beijing 100191, China
| | - Tianpei Hong
- Department of Neurology, Peking University Third Hospital, Beijing 100191, China
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28
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Niu W, Qi Y. An updated meta-analysis of methylenetetrahydrofolate reductase gene 677C/T polymorphism with diabetic nephropathy and diabetic retinopathy. Diabetes Res Clin Pract 2012; 95:110-8. [PMID: 22056717 DOI: 10.1016/j.diabres.2011.10.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Revised: 10/05/2011] [Accepted: 10/10/2011] [Indexed: 01/26/2023]
Abstract
Studies investigating the association of methylenetetrahydrofolate reductase (MTHFR) gene 677C/T polymorphism with diabetic nephropathy and diabetic retinopathy have so far reported inconclusive results. We therefore aim to address this inconclusiveness by conducting a meta-analysis. Random-effects model was applied irrespective of between-study heterogeneity. Data and study quality were assessed in duplicate. A total of 7807 and 1599 subjects from 21 and 8 studies were analyzed for diabetic nephropathy and diabetic retinopathy, respectively. Carriers of 677TT genotype were 1.71 (95% confidence interval [95% CI]: 1.02-2.88; P=0.042) and 2.89 (95% CI: 1.51-5.53; P=0.001) times more likely to develop diabetic nephropathy separately relative to diabetic patients without nephropathy and nondiabetic controls. Likewise, this association was preserved for diabetic patients with retinopathy referring to those without (odds ratio [OR]=1.86; 95% CI: 1.21-2.86; P=0.004). Subgroup analyses showed that ethnicity was a possible confounder, especially in West Asians and Africans, and so were gender and duration of diabetes mellitus in diabetic nephropathy studies. Probability of publication bias was low across all comparisons as reflected by the funnel plot and corresponding test. Taken together, our results demonstrate that MTHFR gene 677TT genotype might confer a moderately augmented risk for diabetic nephropathy and diabetic retinopathy.
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Affiliation(s)
- Wenquan Niu
- State Key Laboratory of Medical Genomics, Rui-Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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29
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Cui WP, Du B, Jia Y, Zhou WH, Liu SM, Cui YC, Ma FZ, Luo P, Miao LN. Is C677T polymorphism in methylenetetrahydrofolate reductase gene a risk factor for diabetic nephropathy or diabetes mellitus in a Chinese population? Arch Med Res 2011; 43:42-50. [PMID: 22209973 DOI: 10.1016/j.arcmed.2011.12.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Accepted: 12/12/2011] [Indexed: 12/22/2022]
Abstract
BACKGROUND AND AIMS To date, case-control studies on the association between C677T polymorphism in methylenetetrahydrofolate reductase (MTHFR) gene and diabetes mellitus (DM) or diabetic nephropathy (DN) in different populations have provided inconclusive results. To clarify the effect of the C677T polymorphism on the risk of both DM and DN in a Chinese population, a meta-analysis was performed. METHODS A comprehensive literature search was conducted to collect data from all case-control observational studies that investigated association of C677T polymorphism in MTHFR gene with DM or DN in a Chinese population. RESULTS Overall, 12 studies in a Chinese population published up to 2011 were combined, and the heterogeneity among them varied from none to moderate. The 677T allele showed significant association with DN (OR = 1.97, 95% CI [1.71, 2.28], p <0.00001), but no relationship with DM (OR = 1.03, 95% CI [0.89, 1.18], p = 0.70) compared with the 677C allele in a Chinese population. Similarly, evidence of significant association with DN was detected in the additive model, the recessive model and the dominant model for allele T (additive model: OR = 3.26, 95% CI [2.46, 4.31], p <0.00001; recessive model: OR = 2.32, 95% CI [1.81, 2.97], p <0.00001; dominant model: OR = 2.35, 95% CI [1.89, 2.91], p <0.00001); however, no relationship with DM was found (additive model: OR = 1.01, 95% CI [0.76, 1.35], p = 0.94; recessive model: OR = 0.98, 95% CI [0.76, 1.26], p = 0.87; dominant model: OR = 1.23, 95% CI [0.91, 1.65], p = 0.18). There were no sources of bias in the selected studies, and the sensitivity analysis (exclusion of studies not in Hardy-Weinberg equilibrium) suggested stability of this meta-analysis. CONCLUSIONS C677T polymorphism in MTHFR gene may be a risk factor for DN, but not for DM, in a Chinese population.
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Affiliation(s)
- Wen-peng Cui
- Department of Nephrology, Second Hospital, Jilin University, Changchun, China.
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Chang YH, Fu WM, Wu YH, Yeh CJ, Huang CN, Shiau MY. Prevalence of methylenetetrahydrofolate reductase C677T and A1298C polymorphisms in Taiwanese patients with Type 2 diabetic mellitus. Clin Biochem 2011; 44:1370-4. [DOI: 10.1016/j.clinbiochem.2011.09.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 08/23/2011] [Accepted: 09/16/2011] [Indexed: 01/15/2023]
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Rahimi Z, Hasanvand A, Felehgari V. Interaction of MTHFR 1298C with ACE D allele augments the risk of diabetic nephropathy in Western Iran. DNA Cell Biol 2011; 31:553-9. [PMID: 21942443 DOI: 10.1089/dna.2011.1364] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
Abstract
The aim of the current study was to examine the influence of interaction between polymorphisms of methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C with angiotensin converting enzyme insertion/deletion (ACE I/D) polymorphism on the risk of diabetic nephropathy (DN). In a case control study using polymerase chain reaction (PCR)- and PCR-restriction fragment length polymorphism (RFLP), the presence of three polymorphisms in 140 patients with type 2 diabetes mellitus (T2DM) with nephropathy including patients with micro- and macro-albuminuria and 72 patients with normoalbuminuria from Western Iran were investigated. In the presence of both MTHFR 677 T and ACE D alleles, there was a trend toward increased risk of DN 2.68-fold (p=0.054). The possession of both MTHFR 677 T and ACE D alleles increased the risk of macro-albuminuria four times (p=0.035). The concomitant presence of both MTHFR 1298 C and ACE D alleles increased the risk of macro-albuminuria 7.8-fold (p=0.012). In addition, the risk of progression from micro- to macro-albuminuria in the presence of both alleles tended to be increased (4.1-fold, p=0.09). Our study for the first time demonstrated a synergistic effect between ACE I/D with either MTHFR C677T or A1298C polymorphism on the increased risk of DN among patients with T2DM. We found that MTHFR 1298 C strongly interacts with the ACE D allele and augments the risk of DN in our population.
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Affiliation(s)
- Zohreh Rahimi
- Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran.
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Movva S, Alluri RV, Venkatasubramanian S, Vedicherla B, Vattam KK, Ahuja YR, Hasan Q. Association of Methylene Tetrahydrofolate Reductase C677T Genotype With Type 2 Diabetes Mellitus Patients With and Without Renal Complications. Genet Test Mol Biomarkers 2011; 15:257-61. [DOI: 10.1089/gtmb.2010.0118] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Sireesha Movva
- Department of Genetics, Bhagwan Mahavir Hospital and Research Centre, Hyderabad, India
- Department of Genetics, Vasavi Hospital and Research Centre, Hyderabad, India
| | - Ravindra V. Alluri
- Department of Genetics and Molecular Medicine, Kamineni Hospitals, Hyderabad, India
| | | | - Bhavani Vedicherla
- Department of Genetics, Bhagwan Mahavir Hospital and Research Centre, Hyderabad, India
| | - Kiran K. Vattam
- Department of Genetics and Molecular Medicine, Kamineni Hospitals, Hyderabad, India
| | - Yog R. Ahuja
- Department of Genetics, Vasavi Hospital and Research Centre, Hyderabad, India
| | - Qurratulain Hasan
- Department of Genetics, Bhagwan Mahavir Hospital and Research Centre, Hyderabad, India
- Department of Genetics, Vasavi Hospital and Research Centre, Hyderabad, India
- Department of Genetics and Molecular Medicine, Kamineni Hospitals, Hyderabad, India
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Uchida Y, Sugiura S, Ando F, Nakashima T, Shimokata H. Hearing impairment risk and interaction of folate metabolism related gene polymorphisms in an aging study. BMC MEDICAL GENETICS 2011; 12:35. [PMID: 21385350 PMCID: PMC3063203 DOI: 10.1186/1471-2350-12-35] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Accepted: 03/07/2011] [Indexed: 12/31/2022]
Abstract
Background Recent investigations demonstrated many genetic contributions to the development of human age-related hearing impairment (ARHI), however, reports of factors associated with a reduction in the ARHI risk are rare. Folate metabolism is essential for cellular functioning. Despite the extensive investigations regarding the roles of folate metabolism related gene polymorphisms in the pathophysiology of complex diseases, such as cancer, cardio-cerebrovascular disease, and atherosclerosis, little is known about the association with ARHI. The aim of this study is to investigate the effects of the methionine synthase (MTR) A2756G and methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphisms on the risk of hearing impairment in middle-aged and elderly Japanese. Methods Data were collected from community-dwelling Japanese adults aged 40-84 years who participated in the Longitudinal Study of Aging biennially between 1997 and 2008. We analyzed cumulative data (5,167 samples in accumulated total) using generalized estimating equations. Results The MTHFR 677T allele was significantly associated with a reduced risk of hearing impairment only when the subjects were wild-type homozygotes for MTR A2756G. The per-T allele odds ratio of MTHFR for the risk of developing hearing impairment was 0.7609 (95% CI: 0.6178-0.9372) in the MTR AA genotype. In addition, a subgroup analysis demonstrated that the favorable effect of the MTHFR 677T allele on the risk of developing hearing impairment was independent of folate and homocysteine level, whereas plasma total homocysteine level was independently associated with an increased risk of developing hearing impairment. The interactive effect of gene polymorphisms associated with folate metabolism may modify the risk of developing hearing impairment after middle age. These results contribute to the elucidation of the causes of ARHI. Conclusions The present study has found that the MTHFR 677T allele has a favorable effect on a risk of hearing impairment in the middle-aged and elderly population, only when the individuals were wild-type homozygotes for MTR A2756G.
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Affiliation(s)
- Yasue Uchida
- Department of Otorhinolaryngology, National Center for Geriatrics and Gerontology, 35 Gengo, Morioka, Obu City, Aichi Prefecture 474-8511, Japan.
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Synergistic effects of the MTHFR C677T and A1298C polymorphisms on the increased risk of micro- and macro-albuminuria and progression of diabetic nephropathy among Iranians with type 2 diabetes mellitus. Clin Biochem 2010; 43:1333-9. [PMID: 20800057 DOI: 10.1016/j.clinbiochem.2010.08.019] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Revised: 08/11/2010] [Accepted: 08/14/2010] [Indexed: 11/24/2022]
Abstract
OBJECTIVES To find whether polymorphisms of methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C are risk factors for diabetic nephropathy (DN) among type 2 diabetes mellitus (T2DM) patients from Western Iran. DESIGN AND METHODS The MTHFR polymorphisms were detected in 72 microalbuminuric, 68 macroalbuminuric and 72 normoalbuinuric T2DM patients by PCR-RFLP. RESULTS The possession of both MTHFR 677T and 1298C alleles increase the risk of microalbuminuria to 4.3-fold (p=0.007) in T2DM patients. The presence of either MTHFR 677T, 1298C allele is sufficient to increase the risk of macroalbuminuria in T2DM patients by 4.1 and 5.5 times (p=0.027, and p=0.006, respectively). The concomitant presence of both 677T and 1298C alleles act in synergy to increase the risk of macroalbuminuria by 20.4-fold (p<0.001) and progression of DN from microalbuminuria to macroalbuminuria (OR=4.73, p=0.01). CONCLUSION Both MTHFR 677T and 1298C alleles increased the susceptibility to the onset and progression of DN in Iranians with T2DM.
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Abstract
Prospective identification of which individuals with diabetes mellitus (DM) are at greatest risk for developing cardiovascular disease (CVD) complications would have considerable public health importance by allowing the allocation of limited resources to be focused on those individuals who would most benefit from aggressive intervention. Over the past 20 years genetic disease association studies have demonstrated that polymorphisms at specific genetic loci may identify those individuals at greatest risk for developing CVD in the setting of DM. This article reviews the evidence accumulated to date on four polymorphic loci with the aim of explaining how these polymorphisms modify the risk for CVD in DM by modifying the functional activity of a specific gene. Use of the knowledge of these genetic differences among individuals in targeting drug therapy (pharmacogenomics) is also discussed.
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Affiliation(s)
- Dan Farbstein
- Technion-Israel Institute of Technology, Haifa, Israel.
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Lai TYY, Chen LJ, Yam GHF, Tham CCY, Pang CP. Development of novel drugs for ocular diseases: possibilities for individualized therapy. Per Med 2010; 7:371-386. [DOI: 10.2217/pme.10.25] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In clinical ophthalmology, new and old drug regimens are available for the treatment of major eye diseases, including potentially blinding conditions, such as glaucoma, and various macular diseases. In glaucoma, therapeutic treatment mainly deals with control of intraocular pressure at low levels but the clinical courses of patients can be very variable. Very often, specific drug combinations and dosages have to be formulated for individual glaucoma patients. In neovascular age-related macular degeneration, choroidal neovascularization can lead to progressive and irreversible visual impairment if not treated early. In recent years, clinical trials using photodynamic therapy with verteporfin and various anti-VEGF antibodies, such as ranibizumab and bevacizumab, have enhanced the treatment outcomes of neovascular age-related macular degeneration. In diabetic macular edema, intravitreal triamcinolone acetonide and anti-VEGF therapy are effective in some patients. Again, responses to treatment are not uniform in all macular patients. Traditional herbal medicine has long been known to play a role in the practice of personalized formulations in Asia. Potential preventive and therapeutic effects have been claimed in individual eye patients. Meanwhile, advanced technologies in molecular biology have led to identification of genes associated with many eye diseases and development of the concept of individual medicine, in which the genotype of a person can be used as a basis for disease prediction or prophylactic treatments. Moreover, pharmacogenomic studies have demonstrated the association of various genotypes or haplotypes with responses to drug therapies, providing hope for tailormade personalized treatments. The combination of genotypic information with clinical features for the prescription of treatment modes in eye diseases is under vigorous research.
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Affiliation(s)
- Timothy YY Lai
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong Eye Hospital, 147K Argyle Street, Kowloon, Hong Kong
| | - Li Jia Chen
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong Eye Hospital, 147K Argyle Street, Kowloon, Hong Kong
| | - Gary HF Yam
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong Eye Hospital, 147K Argyle Street, Kowloon, Hong Kong
| | - Clement CY Tham
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong Eye Hospital, 147K Argyle Street, Kowloon, Hong Kong
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