Folate and vitamin B12 deficiency and hyperhomocysteinemia promote oxidative stress in adult type 2 diabetes

Hyperhomocysteinemia and Disease-Is 10 μmol/L a Suitable New Threshold Limit?

Hyperhomocysteinemia (HHcy) is a medical condition characterized by an abnormally high level of homocysteine (Hcy) in the blood. Homocysteine is a toxic sulfur-containing amino acid that is produced during the metabolism of methionine. Under normal circumstances, Hcy is recycled back to methionine via the remethylation pathway, through the action of various enzymes and vitamins, particularly folic acid (vitamin B9) and B12 used when intracellular methionine levels are low, thus restoring the necessary levels to correctly maintain active protein synthesis. A second pathway, used in cases of intracellular methionine excess, (the trans-sulfuration pathway) is the one that recycles Hcy into cysteine (a precursor of glutathione), first passing through cystathionine (via the enzyme cystathionine beta-synthase), a reaction that requires vitamin B6 in its active form. HHcy has been identified as a risk factor for a variety of disorders, including cardiovascular diseases, multiple sclerosis, diabetes, Alzheimer's and Parkinson's diseases, osteoporosis and cancer. However, it remains unclear whether the slightly elevated concentration of Hcy (Hcy 7-10 μmol/L) is a causative factor or simply a marker of these pathologies. In human plasma, the concentration of Hcy ([Hcy]) is classified as mild (15 to 30 μmol/L), moderate (30 to 100 μmol/L), and severe (greater than 100 μmol/L). Interestingly, many laboratories continue to consider 25 μmol/L as normal. This review seeks to examine the controversial literature regarding the normal range of HHcy and emphasizes that even a [Hcy] level of 10 μmol/L may contribute to the development of several diseases, aiming to discuss whether it would be appropriate to lower the threshold of HHcy normal values.

Potential of postbiotics for the treatment of metabolic disorders

Postbiotics, the next generation of probiotics, are extracts that are free of living and nonviable bacteria and show strong modulatory effects on the gut flora. Examples include vitamin B12, vitamin K, folate, lipopolysaccharides, enzymes, and short-chain fatty acids (SCFAs), representing a subset of essential nutrients commonly found in the human diet. Postbiotics have been observed to demonstrate antiobesity and antidiabetic effects through a variety of mechanisms. These pathways primarily involve an elevation in energy expenditure, a decrease in the formation and differentiation of adipocytes and food intake, modification of lipid and carbohydrate absorption and metabolism, and regulation of gut dysbiosis. Based on these above effects and mechanisms, the use of postbiotics can be considered as potential strategy for the treatment of metabolic disorders.

One-Carbon Metabolism Nutrients, Genetic Variation, and Diabetes Mellitus

Diabetes mellitus (DM) affects about 9.3% of the population globally. Hyperhomocysteinemia (HHcy) has been implicated in the pathogenesis of DM, owing to its promotion of oxidative stress, β-cell dysfunction, and insulin resistance. HHcy can result from low status of one-carbon metabolism (OCM) nutrients (e.g., folate, choline, betaine, vitamin B6, B12), which work together to degrade homocysteine by methylation. The etiology of HHcy may also involve genetic variation encoding key enzymes in OCM. This review aimed to provide an overview of the existing literature assessing the link between OCM nutrients status, related genetic factors, and incident DM. We also discussed possible mechanisms underlying the role of OCM in DM development and provided recommendations for future research and practice. Even though the available evidence remains inconsistent, some studies support the potential beneficial effects of intakes or blood levels of OCM nutrients on DM development. Moreover, certain variants in OCM-related genes may influence metabolic handling of methyl-donors and presumably incidental DM. Future studies are warranted to establish the causal inference between OCM and DM and examine the interaction of OCM nutrients and genetic factors with DM development, which will inform the personalized recommendations for OCM nutrients intakes on DM prevention.

Platelet Metabolic Profiling Reveals Glycolytic and 1-Carbon Metabolites Are Essential for GP VI-Stimulated Human Platelets-Brief Report

BACKGROUND

Evolving evidence suggests that besides signaling pathways, platelet activation involves a complex interplay between metabolic pathways to support thrombus growth. Selective targeting of metabolic checkpoints may inhibit platelet activation and provide a novel antiplatelet strategy. We, therefore, examined global metabolic changes that occur during the transition of human platelets from resting to an activated state to identify metabolites and associated pathways that contribute to platelet activation.

METHODS

We performed metabolic profiling of resting and convulxin-stimulated human platelet samples. The differential levels, pathway analysis, and PCA (principal component analysis) were performed using Metaboanalyst. Metascape was used for metabolite network construction.

RESULTS

Of the 401 metabolites identified, 202 metabolites were significantly upregulated, and 2 metabolites were downregulated in activated platelets. Of all the metabolites, lipids scored highly and constituted ≈50% of the identification. During activation, aerobic glycolysis supports energy demand and provides glycolytic intermediates required by metabolic pathways. Consistent with this, an important category of metabolites was carbohydrates, particularly the glycolysis intermediates that were significantly upregulated compared with resting platelets. We found that lysophospholipids such as 1-palmitoyl-GPA (glycero-3-phosphatidic acid), 1-stearoyl-GPS (glycero-3-phosphoserine), 1-palmitoyl-GPI (glycerophosphoinositol), 1-stearoyl-GPI, and 1-oleoyl-GPI were upregulated in activated platelets. We speculated that platelet activation could be linked to 1-carbon metabolism, a set of biochemical pathways that involve the transfer and use of 1-carbon units from amino acids, for cellular processes, including nucleotide and lysophospholipid synthesis. In alignment, based on pathway enrichment and network-based prioritization, the metabolites from amino acid metabolism, including serine, glutamate, and branched-chain amino acid pathway were upregulated in activated platelets, which might be supplemented by the high levels of glycolytic intermediates.

CONCLUSIONS

Metabolic analysis of resting and activated platelets revealed that glycolysis and 1-carbon metabolism are necessary to support platelet activation.

Supplementing semen extenders with a combination of phosphorus and vitamin B12 Improves post-thawed cryopreserved rooster semen quality

Semen cryopreservation is an important technique for preserving the genetic material of numerous species. However, frozen semen is highly susceptible to sperm DNA damage and reduced motility, resulting in decreased fertility. The standard method for cryopreservation and several approaches have not been elucidated. This study aimed to determine the effects of supplementing rooster semen extender with a combination of phosphorus and vitamin B12 on cryopreserved semen quality. Semen was collected weekly via dorso-abdominal massage from 57 Burmese × Vietnam-crossbred Thai native roosters aged 1-3 years. In total, 139 semen samples were collected, pooled, and diluted to 200 million sperm per dose. The pooled sample was divided into six experimental groups: a control group (0.00%) diluted with modified Beltville Poultry Semen Extender (BPSE) and five treatment groups diluted with modified BPSE supplemented with phosphorus and vitamin B12 at concentrations 0.02, 0.04, 0.06, 0.08, and 0.10%, respectively. The semen samples were frozen and evaluated at 0, 15, and 30 min after thawing. Sperm kinematic parameters were determined using a computer-assisted sperm analysis system. Sperm quality was evaluated by measuring sperm viability, mitochondrial activity, acrosome integrity, and plasma membrane integrity. Statistical analyses were performed using a general linear mixed model (MIXED) in SAS. Factors in the statistical model were experimental groups, time after thawing, and interaction between experimental groups and time after thawing. Total and progressive motilities were greater in semen supplemented with 0.04% phosphorus and vitamin B12 compared with those in the control (p < 0.05). At 15 min post-thawing, VCL, VAP, and HPA in the 0.04% phosphorus and vitamin B12 supplementation group was greater than that in the control (p < 0.05). Phosphorus and vitamin B12 supplementation did not affect sperm kinematics at 0 and 30 min after thawing (p > 0.05). All the sperm parameters that were tested for the 0.04% phosphorus and vitamin B12 supplementation group in modified BPSE were the highest at all the timepoints after thawing. Thus, supplementing frozen semen extender with 0.04% phosphorus and vitamin B12 increased sperm motility, sperm kinematic parameters, and sperm quality.

A Narrative Review on Strategies for the Reversion of Prediabetes to Normoglycemia: Food Pyramid, Physical Activity, and Self-Monitoring Innovative Glucose Devices

In 2019, "Nutrition Therapy for Adults with Diabetes or Prediabetes: A Consensus Report" was published. This consensus report, however, did not provide an easy way to illustrate to subjects with prediabetes (SwPs) how to follow a correct dietary approach. The purpose of this review is to evaluate current evidence on optimum dietary treatment of SwPs and to provide a food pyramid for this population. The pyramid built shows that everyday consumption should consist of: whole-grain bread or potatoes eaten with their skins (for fiber and magnesium) and low glycemic index carbohydrates (GI < 55%) (three portions); fruit and vegetables (5 portions), in particular, green leafy vegetables (for fiber, magnesium, and polyphenols); EVO oil (almost 8 g); nuts (30 g, in particular, pistachios and almonds); three portions of dairy products (milk/yogurt: 300-400 g/day); mineral water (almost 1, 5 L/day for calcium intake); one glass of wine (125 mL); and three cups of coffee. Weekly portions should include fish (four portions), white meat (two portions), protein plant-based food (four portions), eggs (egg portions), and red/processed meats (once/week). At the top of the pyramid, there are two pennants: a green one means that SwPs need some personalized supplementation (if daily requirements cannot be satisfied through diet, vitamin D, omega-3, and vitamin B supplements), and a red one means there are some foods and factors that are banned (simple sugar, refined carbohydrates, and a sedentary lifestyle). Three to four times a week of aerobic and resistance exercises must be performed for 30-40 min. Finally, self-monitoring innovative salivary glucose devices could contribute to the reversion of prediabetes to normoglycemia.

Relationship of Vitamin B12 Levels With Different Degrees of Obesity and Diabetes Mellitus

INTRODUCTION

The potential influence of micronutrient status on obesity should be considered. Nevertheless, previous research examining the relationship between serum vitamin B12 levels and obesity has yielded inconclusive results. The objective of this study was to investigate the associations between serum vitamin B12 levels and obesity and diabetes mellitus (DM) in a population consisting of persons aged 18 years and older.

METHODS

A retrospective case-control research was undertaken on a sample of 1024 individuals aged 18 years and older who were admitted to a tertiary healthcare facility (Recep Tayyip Erdoğan University Education and Research Hospital, Rize) for either overweight-related issues or routine check-ups. The primary objective of this study was to assess the B12 levels of these individuals. The researcher recorded the body mass index (BMI) and history of DM for all subjects.

RESULTS

The study comprised a total of 1024 participants, consisting of 834 females and 190 males. The levels of vitamin B12 in women were found to be 308±113 pg/mL, while in men, the levels were 304±125 pg/mL. The results of the statistical analysis indicate that there is no statistically significant disparity in vitamin B12 levels between males and females (p=0.748). There was a statistically significant positive correlation seen between age and B12 levels; however, the magnitude of this connection was found to be minor (p=0.000, R2=0.017). The study findings revealed that out of the 1,024 individuals evaluated, 179 individuals exhibited B12 levels below 200, while 845 individuals displayed vitamin B12 levels above 200. The study findings indicated that there was no statistically significant distinction observed in the occurrence of obesity and DM in relation to vitamin B12 deficiency (p = 0.938, p = 0.08, respectively).

CONCLUSION

The results of this study offer empirical support for the notion that there is no significant difference in vitamin B12 levels between individuals afflicted with obesity and diabetes and those unaffected by these conditions. Interestingly, it was shown that serum B12 levels exhibited a modest increase with advancing age.

Co-exposure to multiple vitamins and the risk of all-cause mortality in patients with diabetes

Objective

Although the effect of vitamins on the risk of mortality in diabetic patients has been reported, most studies focus on individual vitamins. However, humans are often exposed to multiple vitamins simultaneously in daily life. Therefore, it is worth exploring the effects of co-exposure to multiple vitamins on the risk of mortality in diabetic patients.

Methods

This study included diabetic patients aged ≥20WD years who participated in NHANES from 2003 to 2006. An unsupervised K-means clustering method was used to cluster eight vitamins in serum into several patterns of co-exposure to multiple vitamins, and the Cox proportional hazards model was used to evaluate the impact of different patterns of co-exposure to multiple vitamins on the risk of all-cause mortality in diabetic patients.

Results

Three patterns of co-exposure to multiple vitamins were generated based on K-means clustering, namely, low-level, moderate-level, and high-level. Among the 484 diabetic patients, with a median follow-up of 13.7 years, a total of 211 deaths occurred. After adjusting for covariates, the individual vitamins had varying effects on the risk of all-cause mortality in diabetic patients. Compared to the low-level group of co-exposure to multiple vitamins, the high-level group significantly reduced the risk of all-cause mortality in diabetic patients, with a HR of 0.42 (95% CI: 0.20, 0.87). Subgroup analysis demonstrated that high levels of co-exposure to multiple vitamins significantly reduced the risk of all-cause mortality in males, individuals aged ≥ 60 years, and non-Hispanic White people with diabetes compared to the low-level group, with HR of 0.42 (95% CI: 0.18, 0.98), 0.53 (95% CI: 0.26, 0.98), and 0.26 (95% CI: 0.12, 0.58) respectively.

Conclusion

While individual vitamins had different effects on the risk of all-cause mortality in patients with diabetes, high-level co-exposure to multiple vitamins significantly reduced the risk of all-cause mortality in patients with diabetes, with differences observed among genders, ages, and race. This suggests that when developing vitamin intervention strategies for patients with diabetes, consideration should be given not only to the dosage of individual vitamins but also to the variations between different population groups.

Folate deficiency may increase the risk for elevated TSH in patients with type 2 diabetes mellitus

BACKGROUND

Type 2 diabetes mellitus (T2DM) and thyroid dysfunction (TD) are two common chronic endocrine disorders that often coexist. Folate deficiency has been reported to be related with the onset and development of T2DM. However, the relationship between folate deficiency and TD remains unclear. This study aims to investigate the association of serum folate with TD in patients with T2DM.

METHODS

The study used data on 268 inpatients with T2DM in the Beijing Chao-yang Hospital, Capital Medical University from October 2020 to February 2021. Thyroid stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4), and serum folate were measured with chemiluminescence immunoassay (CLIA), and folate deficiency was defined as a serum folate concentration < 4.4 ng/mL. Ordinary least squares regression models were used to assess the association of serum folate with TSH concentration. Multivariable logistic regression models were performed to explore the correlation of folate deficiency and the risk for elevated TSH.

RESULTS

15.3% of T2DM patients had TD. Among those patients with TD, 80.5% had elevated TSH. Compared with the normal-TSH and low-TSH groups, the prevalence of folate deficiency was significantly higher in the elevated-TSH group (P < 0.001). Serum folate level was negatively associated with TSH (β=-0.062, 95%CI: -0.112, -0.012). Folate deficiency was associated with the higher risk for elevated TSH in patients with T2DM (OR = 8.562, 95%CI: 3.108, 23.588).

CONCLUSIONS

A low serum folate concentration was significantly associated with a higher risk for elevated TSH among T2DM patients.

Is the clinical course of non-arteritic ischemic optic neuropathy associated with oxidative damage and the dynamics of the antioxidant response?

PURPOSE

Oxidative stress is known to be a decisive factor in the wide etiopathogenesis of optic neuropathy. This study aimed to comprehensively evaluate the interaction of optic neuropathy's clinical course with systemic oxidative damage and antioxidant response dynamics in a large series.

METHODS

This case-controlled clinical study included 33 non-arteritic anterior ischemic optic neuropathy (NAION) patients and 32 healthy individuals. Extensive systemic oxidation profiles were statistically compared between the two groups, and correlations between the clinical and biochemical data in the study group were analyzed.

RESULTS

Vitamin E and malondialdehyde (MDA) levels were significantly higher in the study group. Significant correlations were observed in the analyses between clinical findings and oxidative stress parameters. Correlations between vitamin E and intraocular pressure (IOP), between B12 and cup-to-disk ratio (c/d), between antioxidant glutathione and superoxide dismutase (SOD) enzyme systems, and between uric acid (UA) and age were found to be very significant. As significant correlations were found in either clinical and biochemical data or in oxidative stress parameters, correlations between vitamin E and cholesterol, MDA were found to be very significant.

CONCLUSIONS

This study not only supplies significant information regarding oxidative damage and antioxidant response in NAION, but also points out the specific interactions of neuromodulators, like vitamin E, in intracellular signaling pathways and regulation mechanisms. A better reading of these connections may help improve diagnosis, follow-ups and treatment criteria and strategies.

Homocysteine-Potential Novel Diagnostic Indicator of Health and Disease in Horses

Homocysteine is an endogenous, non-protein sulfuric amino acid, an intermediate metabolite formed by the methionine transmethylation reaction. Its elevated serum concentration in humans, hyperhomocysteinemia, is a sensitive indicator and a risk factor for coagulation disorders, cardiovascular diseases and dementia. However, the role of homocysteine in veterinary species has not been unequivocally established. Although some research has been conducted in dogs, cats, cattle and pigs, relatively few studies on homocysteine have been conducted in horses. So far, it has been established in this species that homocysteine has an atherogenic effect, plays a role in early embryo mortality and is responsible for the induction of oxidative stress. These preliminary findings support establishing a reference range in a normal population of horses, including horses in training and merit further investigations into the role of this amino acid in health and disease in this species.

Dose-response association between dietary folate and niacin intakes with diabetes among Chinese adults: a cross-sectional study

BACKGROUND

The aim of this study was to examine the relationship between dietary intake of folate and niacin and diabetes risk in Chinese adults.

METHODS

This is a cross-sectional study. Demographic and anthropometric data along with information on dietary intake of vitamins were collected, and eligible participants were recruited to complete the questionnaire. A binary logistic regression analysis was conducted to examine the association between dietary intake of vitamins and diabetes risk, with adjustment for potential confounders. Non-linear dose-response relationships between dietary intake of folate and niacin and diabetes risk were also evaluated using adjusted restricted cubic splines.

RESULTS

Of the 3106 eligible participants, 15.9% had diabetes. Median folate was significantly higher in diabetic patients than in controls (32.030 vs. 27.600 gμ), while median niacin was significantly lower (7.000 vs. 7.900 mg). After controlling for potential confounders, binary logistic regression analysis showed that each unit increase in folate intake was associated with a 1.002-fold increase in the risk of developing diabetes (odds ratio (OR) = 1.002; 95% confidence interval (CI) 1.000-1.004; P = 0.022), while each unit increase in niacin intake was associated with a 3.5% reduction in diabetes risk (OR = 0.965; 95% CI 0.944-0.986; P = 0.001). The plots of restricted cubic splines presented an atypical inverted U-shaped association between dietary intake of folate and diabetes risk.

CONCLUSIONS

Diabetic patients had a low intake of vitamins, especially the B vitamins. Dietary intake of folate and niacin tended to be independently associated with the risk of diabetes. Nevertheless, this study is observational and a large-scale randomized controlled trial is yet to be conducted, which will add to the evidence of the study results.

Association of Folic Acid Supplementation, Dietary Folate Intake and Serum Folate Levels with Risk of Gestational Diabetes Mellitus: A Matched Case-Control Study

Periconceptional folate supplementation is prevalent, raising concerns about possible side effects. The aim of this study was to investigate the associations of folic acid supplementation, dietary folate, serum folate with gestational diabetes mellitus (GDM) risk. In this matched case-control study, 81 pregnant women with GDM (cases) and 81 pregnant women with non-GDM (controls) were identified through age difference (≤3 y) and parity (Both primipara or multipara women) matching, and serum folate levels were measured during the GDM screening (24-28 gestational wk). Folic acid supplementation and dietary folate intake from three months prepregnancy through midpregnancy were assessed using a self-reported questionnaire and food frequency questionnaire. Multivariate binary logistic regression models were used to evaluate the association between folate and GDM. After adjusting for confounding factors, we observed that compared with folic acid supplementation dose ≤400 μg/d, pregnancies without folic acid supplementation and supplemental dose >800 μg/d were associated with GDM risk (adjusted odds ratio=7.25, 95% confidence interval: 1.34-39.36; adjusted odds ratio=4.20, 95% confidence interval: 1.03-17.22), while no significant association with a 400-800 μg/d dose of folic acid supplementation and GDM. Compared with folic acid supplementation dose ≤24 wk, pregnancies without folic acid supplementation were associated with GDM risk (adjusted odds ratio=6.70, 95% confidence interval: 1.22-36.77), while no significant association with folic acid supplementation dose >24 wk and GDM. No significant association of dietary folate and serum folate with GDM was found. No or a higher dose of folic acid supplementation would increase GDM risk and a dose of <800 μg/d is the safe dose.

Potential Anti-Alzheimer Properties of Mogrosides in Vitamin B12-Deficient Caenorhabditis elegans

Vitamin B12 deficiency can lead to oxidative stress, which is known to be involved in neurodegenerative diseases such as Alzheimer's disease (AD). Mogrosides are plant-derived triterpene glycosides that exhibit anti-inflammatory and antioxidant activity in animal cell lines and mouse models. Since amyloid-β toxicity is known to cause oxidative stress and damage to brain cells, we hypothesized that mogrosides may have a protective effect against AD. In this study, we investigated the potential anti-AD effect of mogrosides in vitamin B12-deficient wild-type N2 and in transgenic CL2355 Caenorhabditis elegans expressing amyloid-β peptide. Our data indicated that mogrosides have a beneficial effect on the lifespan and egg-laying rate of N2 and vitamin B12-deficient N2 worms. Additionally, the results revealed that mogrosides can effectively delay the paralysis of CL2355 worms as determined by serotonin sensitivity assay. Our analysis showed that mogrosides increase the expression of oxidative protective genes in N2 worms fed with vitamin B12-deficient OP50 bacterium. We conclude that mogrosides may exert preventative rather than curative effects that counteract the detrimental vitamin B12-deficient environment in N2 and CL2355 C. elegans by modulating oxidation-related gene expression.

Vitamin B12 administration prevents ethanol-induced learning and memory impairment through re-establishment of the brain oxidant/antioxidant balance, enhancement of BDNF and suppression of GFAP

There are growing evidence indicating that the adolescent brain is persistently affected by the use of psychostimulant agents. In this regard, alcohol drinking has become rather common among the adolescents in many societies during the last decade. It is currently well known that long-term ethanol exposure deteriorates various cognitive functions such as learning and memory. Mechanistically, these adverse effects have been shown to be mediated by oxidative damage to central nervous system. On the other hand, Vit-B12 is known to improve cognitive performance by suppression of oxidative parameters. Thus, in the present study we aimed to test whether treatment by Vit-B12 could prevent ethanol-induced complications in mice using behavioral and biochemical methods. Different groups of male Syrian mice received ethanol, ethanol+Vit-B12, Vit-B12 alone, or saline during adolescence and then learning and memory functions were assessed by Morris water maze (MWM) and Passive Avoidance (PA) tests. Finally, mice were sacrificed for measurement of biochemical factors. Results indicated that, adolescent ethanol intake impairs learning and memory function through exacerbation of oxidative stress and Vit-B12 treatment improves these complications by re-establishment of oxidant/anti-oxidant balance in CNS. Moreover, we found that Vit-B12 prevents ethanol-induced reduction of BDNF and enhancement of GFAP and acetylcholinesterase (AChE) activity. In conclusion, it seems that Vit-B12 supplementation could be used as an effective therapeutic strategy to prevent learning and memory defects induced by chronic alcohol intake during adolescence.

Evaluation of thiol disulfide balance in adolescents with vitamin B12 deficiency

BACKGROUND

Vitamin B12 is an important vitamin for metabolism and affects many mechanisms in the body including neuronal migration, DNA synthesis, neurotransmitter synthesis, brain and cognitive development. Increased oxidative stress in the body leads to the damage of the child development, but also plays a crucial role in the pathogenesis of many diseases encountered in the childhood period. Our aim is to investigate whether or not B12 deficiency is associated with dynamic thiol/disulfide homeostasis in adolescent patients.

METHODS

This is a case-controlled observational study consisting of 45 adolescent patients with vitamin b12 deficiency and a control group consisting of 45 healthy adolescent. Patients between 11 and 18 ages who applied to the outpatient clinic for the first time with one of the complaints of headache were selected due to their decreased school performance, dizziness, and fatigue. Hemogram, vitamin B12, homocysteine levels and oxidative stress parameters such as native and total thiol disulfide levels and ratios of disulfide/native thiol, disulfide/total thiol, and native thiol/total thiol were measured from the patients.

RESULTS

Vitamin B12 level was found to be significantly lower in vitamin B12 deficiency group (p < 0.001). The serum disulfide level was found to be 27.5 ± 8.38 in the case group and 20.5 ± 8.36 in the control group (p < 0.001). In the multiple linear regression analysis, it was determined that the independent variables of native thiol, homocysteine and disulfide levels effected of vitamin B12 levels (p < 0.001, p < 0.001, p < 0.005 respectively; R² = 0.62).

CONCLUSION

The results obtained in terms of the effect of vitamin B12 deficiency on oxidative stress in adolescents are remarkable. The increase in oxidative stress parameters in the patient group may also suggest that oxidative stress plays a vital role in vitamin B12 deficiency in adolescence.

The role of dietary antioxidants in type 2 diabetes and neurodegenerative disorders: An assessment of the benefit profile

Healthy diet is vital to cellular health. The human body succumbs to numerous diseases which afflict severe economic and psychological burdens on the patient and family. Oxidative stress is a possible crucial regulator of various pathologies, including type 2 diabetes and neurodegenerative diseases. It generates reactive oxygen species (ROS) that trigger the dysregulation of essential cellular functions, ultimately affecting cellular health and homeostasis. However, lower levels of ROS can be advantageous and are implicated in a variety of signaling pathways. Due to this dichotomy, the terms oxidative "eustress," which refers to a good oxidative event, and "distress," which can be hazardous, have developed. ROS affects multiple signaling pathways, leading to compromised insulin secretion, insulin resistance, and β-cell dysfunction in diabetes. ROS is also associated with increased mitochondrial dysfunction and neuroinflammation, aggravating neurodegenerative conditions in the body, particularly with age. Treatment includes drugs/therapies often associated with dependence, side effects including non-selectivity, and possible toxicity, particularly in the long run. It is imperative to explore alternative medicines as an adjunct therapy, utilizing natural remedies/resources to avoid all the possible harms. Antioxidants are vital components of our body that fight disease by reducing oxidative stress or nullifying the excess toxic free radicals produced under various pathological conditions. In this review, we focus on the antioxidant effects of components of dietary foods such as tea, coffee, wine, oils, and honey and the role and mechanism of action of these antioxidants in alleviating type 2 diabetes and neurodegenerative disorders. We aim to provide information about possible alternatives to drug treatments used alone or combined to reduce drug intake and encourage the consumption of natural ingredients at doses adequate to promote health and combat pathologies while reducing unwanted risks and side effects.

Circulating homocysteine and folate concentrations and risk of type 2 diabetes: A retrospective observational study in Chinese adults and a Mendelian randomization analysis

Background

The relation between circulating homocysteine (hcy) and folate concentrations and risk of type 2 diabetes mellitus (T2DM) has been evaluated in several observational studies with inconsistent results; and it is unclear about their causal relationships. Our aim was to assess the causality association between circulating hcy or folate concentrations and the development of T2DM using Mendelian randomization (MR) analysis, based on results of an observational study in Chinese adults.

Methods

We conducted an observational study of 370 patients with T2DM and 402 controls after routine physical examination who consulted at the Zhongnan Hospital of Wuhan University between March 2021 and December 2021. Correlations between hcy and folate and the incidence of T2DM were quantified using logistic regression models. Two-sample MR analysis was conducted using summary statistics of genetic variants gained from 2 genome-wide association studies (GWAS) on circulating hcy and folate concentrations in individuals of European ancestry and from an independent GWAS study based on DIAMANTE meta-analysis.

Results

In the observational study, after logistic regression with multiple adjustment, lower hcy and higher folate levels were identified to be associated with the risk of T2DM, with OR (95% CI) for hcy of 1.032 (1.003–1.060); while 0.909 (0.840–0.983) for folate. In the MR analysis, the OR for T2DM was 1.08 (95% CI: 0.95, 1.21; P = 0.249) for each SD unit increase in genetically predicted homocysteinemia and the OR for T2DM per SD increase in genetically predicted folate elevation was 0.80 (95% CI: 0.60, 1.00, P = 0.026).

Conclusions

We discovered that high circulating hcy and low folate concentrations were related with an increased risk of developing T2DM in Chinese adults. Moreover, MR analysis provided genetic evidence for a possible causal relationship between serum folate and the risk of T2DM.

Association between methyl donor nutrients and metabolic health status in overweight and obese adolescents

Limited evidence is available regarding the association of methyl donor nutrients and adolescents' metabolic health. Therefore, we investigated the relation between a combination of methyl donor nutrients and metabolic health status of overweight and obese Iranian adolescents. In this cross-sectional study, 203 overweight/obese adolescents were included, using a multistage cluster random-sampling method. Dietary intakes were assessed by a validated food frequency questionnaire. Methyl donor nutrient score (MDNS) was constructed based on deciles of vitamins B2, B6, B9, B12, methionine, choline and betaine. Glycemic profile, lipid profile, blood pressure and anthropometric indices were collected. Participants were classified as metabolically healthy obese or unhealthy obese (MUO) based on International Diabetes Federation (IDF) and IDF/Homeostasis Model Assessment Insulin Resistance (HOMA-IR) definitions. Mean age of adolescents was 13.98 [Formula: see text] 1.61 y and 50.2% of them was girls. After controlling all of the confounders, individuals in the top tertile of MDNS, had lower odds of MUO (OR 0.36; 95% CI 0.13-0.95) according to IFD criteria. Considering IDF/HOMA-IR criteria, an inverse marginally significant association was observed between the highest tertile of MDNS and odds of MUO (OR 0.36; 95% CI 0.12-1.02) in the fully-adjusted model. Furthermore, significant inverse association was found between each unit increase in MDNS and odds of MUO based on IDF criteria, but not for IDF/HOMA-IR definition. We found that overweight/obese adolescents with higher dietary intakes of methyl donor nutrients were less likely to be metabolically unhealthy. Further studies are needed to confirm the findings.

Beneficial effects of vitamin B12 treatment in pediatric patients diagnosed with vitamin B12 deficiency regarding total-native thiol, oxidative stress, and mononuclear leukocyte DNA damage

Vitamin B₁₂ is involved in biochemical metabolic pathways. B₁₂ deficiency is common in childhood when the need for the vitamin increases and growth and development occur. Various hematological, neurological, psychiatric, and gastrointestinal disorders are observed in its deficiency. In addition, B₁₂ deficiency is associated with oxidative stress and DNA damage. Therefore, the aim of our study is to evaluate oxidative stress, thiol/disulfide homeostasis, and DNA damage pre and post-treatment in children diagnosed with B₁₂ deficiency. A total of 40 children with B₁₂ deficiency were included in the study after the consent form was approved. Blood was drawn from children pre and posttreatment. Hemoglobin (HGB), hematocrit (HCT), and red blood cells (RBC) were measured by autoanalyzer; total antioxidant status (TAS), total oxidant status (TOS), total thiol (TT), and native thiol (NT) were measured by the photometric method, and DNA damage was analyzed by the comet assay method. Oxidative stress index (OSI) and disulfide (DIS) values were calculated. As a result of the experiments, HGB, HCT, and RBC increased with treatment. While TAS, TT, and NT as antioxidant parameters increased; TOS, OSI, and DIS decreased with treatment compared to pretreatment. DNA damage was also found to decrease with treatment. Additionally, these data were statistically significant (p < 0.001). It was found that oxidative stress and DNA damage decreased with oral B₁₂ treatment in children with B₁₂ deficiency, and clinical parameters were also improved.

Postbiotics as potential new therapeutic agents for metabolic disorders management

The prevalence of obesity, diabetes, non-alcoholic fatty liver disease, and related metabolic disorders has been steadily increasing in the past few decades. Apart from the establishment of caloric restrictions in combination with improved physical activity, there are no effective pharmacological treatments for most metabolic disorders. Many scientific-studies have described various beneficial effects of probiotics in regulating metabolism but others questioned their effectiveness and safety. Postbiotics are defined as preparation of inanimate microorganisms, and/or their components, which determine their safety of use and confers a health benefit to the host. Additionally, unlike probiotics postbiotics do not require stringent production/storage conditions. Recently, many lines of evidence demonstrated that postbiotics may be beneficial in metabolic disorders management via several potential effects including anti-inflammatory, antibacterial, immunomodulatory, anti-carcinogenic, antioxidant, antihypertensive, anti-proliferative, and hypocholesterolaemia properties that enhance both the immune system and intestinal barrier functions by acting directly on specific tissues of the intestinal epithelium, but also on various organs or tissues. In view of the many reports that demonstrated the high biological activity and safety of postbiotics, we summarized in the present review the current findings reporting the beneficial effects of various probiotics derivatives for the management of metabolic disorders and related alterations.

The Controversial Role of HCY and Vitamin B Deficiency in Cardiovascular Diseases

Plasma homocysteine (HCY) is an established risk factor for cardiovascular disease CVD and stroke. However, more than two decades of intensive research activities has failed to demonstrate that Hcy lowering through B-vitamin supplementation results in a reduction in CVD risk. Therefore, doubts about a causal involvement of hyperhomocysteinemia (HHcy) and B-vitamin deficiencies in atherosclerosis persist. Existing evidence indicates that HHcy increases oxidative stress, causes endoplasmatic reticulum (ER) stress, alters DNA methylation and, thus, modulates the expression of numerous pathogenic and protective genes. Moreover, Hcy can bind directly to proteins, which can change protein function and impact the intracellular redox state. As most mechanistic evidence is derived from experimental studies with rather artificial settings, the relevance of these results in humans remains a matter of debate. Recently, it has also been proposed that HHcy and B-vitamin deficiencies may promote CVD through accelerated telomere shortening and telomere dysfunction. This review provides a critical overview of the existing literature regarding the role of HHcy and B-vitamin deficiencies in CVD. At present, the CVD risk associated with HHcy and B vitamins is not effectively actionable. Therefore, routine screening for HHcy in CVD patients is of limited value. However, B-vitamin depletion is rather common among the elderly, and in such cases existing deficiencies should be corrected. While Hcy-lowering with high doses of B vitamins has no beneficial effects in secondary CVD prevention, the role of Hcy in primary disease prevention is insufficiently studied. Therefore, more intervention and experimental studies are needed to address existing gaps in knowledge.

Balancing reactive oxygen species generation by rebooting gut microbiota

Reactive oxygen species (ROS; free radical form O₂ ^•‾ , superoxide radical; OH^• , hydroxyl radical; ROO^• , peroxyl; RO^• , alkoxyl and non-radical form ¹ O₂ , singlet oxygen; H₂ O₂ , hydrogen peroxide) are inevitable companions of aerobic life with crucial role in gut health. But, overwhelming production of ROS can cause serious damage to biomolecules. In this review, we have discussed several sources of ROS production that can be beneficial or dangerous to the human gut. Microorganisms, organelles and enzymes play crucial role in ROS generation, where, NOX1 is the main intestinal enzyme, which produce ROS in the intestine epithelial cells. Previous studies have reported that probiotics play significant role in gut homeostasis by checking the ROS generation, maintaining the antioxidant level, immune system and barrier protection. With current knowledge, we have critically analyzed the available literature and presented the outcome in the form of bubble maps to suggest the probiotics that help in controlling the ROS-specific intestinal diseases, such as inflammatory bowel disease (IBD) and colon cancer. Finally, it has been concluded that rebooting of the gut microbiota with probiotics, postbiotics or fecal microbiota transplantation (FMT) can have crucial implications in the structuring of gut communities for the personalized management of the gastrointestinal (GI) diseases.

Deficiency of folate and vitamin B12 increases oxidative stress in chronic pancreatitis patients

BACKGROUND

Folate and vitamin B₁₂ are involved in metabolic reactions for combating oxidative stress. We measured erythrocyte folate and plasma vitamin B₁₂ and compared these with blood antioxidants - erythrocyte glutathione (GSH), glutathione peroxidase (GPx), superoxide dismutase (SOD), and plasma vitamin C - and marker of lipid peroxidation, thiobarbituric acid reactive substance (TBARS), in chronic pancreatitis (CP) patients.

METHODS

One hundred and seventy-five CP patients (91 tropical, 84 alcoholic) and 113 healthy controls were recruited. Erythrocyte folate and plasma vitamin B₁₂ were measured using microbiological assay, and antioxidant levels and erythrocyte TBARS by spectrophotometry.

RESULTS

Erythrocyte folate and plasma vitamin B₁₂ were significantly lower in CP patients than controls (225.4 ± 9.13 vs. 380.38 ± 17.29 nmol/L, p < 0.001 and 233.23 ± 10.4 vs. 338.84 ± 19.01 pmol/L, p < 0.001), and in diabetic- vs. non-diabetic CP patients. Blood antioxidant levels were significantly lower and TBARS was higher in CP patients as compared to controls. Low folate level correlated with low GSH levels (r = 0.314, p < 0.001). CP patients with low folate and vitamin B₁₂ had low GSH and GPx levels as compared to patients with normal folate and vitamin B₁₂ levels. Low vitamin B₁₂ level was associated with 3.24 (95% CI 1.11-9.46, p < 0.05) fold increased risk of pancreatic insufficiency. Smoking was associated with 9.82 (95% confidence interval [CI] 3.3-29.22, p < 0.05) fold increased risk of having low folate levels.

CONCLUSION

Low folate and vitamin B₁₂ levels were associated with increased oxidative stress in CP patients.

OUP accepted manuscript

Type 2 diabetes (T2D) is associated with elevated frequencies of micronuclei (MNi) and other DNA damage biomarkers. Interestingly, individuals with T2D are more likely to be deficient in micronutrients (folic acid, pyridoxal-phosphate, cobalamin) that play key roles in one-carbon metabolism and maintaining genomic integrity. Furthermore, it has recently been shown that deficiencies in these nutrients, in particular folic acid leaves cells susceptible to glucose-induced DNA damage. Therefore, we sought to investigate if the B lymphoblastoid WIL2-NS cell line cultured under folic acid-deficient conditions was more sensitive to DNA damage induced by glucose, or the reactive glycolytic byproduct methylglyoxal (MGO) and subsequent advanced glycation endproduct formation. Here, we show that only WIL2-NS cultured under folic acid-deficient conditions (23 nmol/l) experience an increase in MNi frequency when exposed to high concentrations of glucose (45 mmol/l) or MGO (100 µmol/l). Furthermore, we showed aminoguanidine, a well-validated MGO and free radical scavenger was able to prevent further MNi formation in folic acid-deficient cells exposed to high glucose, which may be due to a reduction in MGO-induced oxidative stress. Interestingly, we also observed an increase in MGO and other dicarbonyl stress biomarkers in folic acid-deficient cells, irrespective of glucose concentrations. Overall, our evidence shows that folic acid-deficient WIL2-NS cells are more susceptible to glucose and/or MGO-induced MNi formation. These results suggest that individuals with T2D experiencing hyperglycemia and folic acid deficiency may be at higher risk of chromosomal instability.

Homocysteine metabolism as the target for predictive medical approach, disease prevention, prognosis, and treatments tailored to the person

Homocysteine (Hcy) metabolism is crucial for regulating methionine availability, protein homeostasis, and DNA-methylation presenting, therefore, key pathways in post-genomic and epigenetic regulation mechanisms. Consequently, impaired Hcy metabolism leading to elevated concentrations of Hcy in the blood plasma (hyperhomocysteinemia) is linked to the overproduction of free radicals, induced oxidative stress, mitochondrial impairments, systemic inflammation and increased risks of eye disorders, coronary artery diseases, atherosclerosis, myocardial infarction, ischemic stroke, thrombotic events, cancer development and progression, osteoporosis, neurodegenerative disorders, pregnancy complications, delayed healing processes, and poor COVID-19 outcomes, among others. This review focuses on the homocysteine metabolism impairments relevant for various pathological conditions. Innovative strategies in the framework of 3P medicine consider Hcy metabolic pathways as the specific target for in vitro diagnostics, predictive medical approaches, cost-effective preventive measures, and optimized treatments tailored to the individualized patient profiles in primary, secondary, and tertiary care.

Homocysteine levels and cardiovascular risk factors in children and adolescents: systematic review and meta-analysis

CONTEXT

Studies have indicated that homocysteine levels are nontraditional markers for cardiovascular disease. The onset of atherosclerotic disease begins in childhood and adolescence; thus, prevention of its risk factors should occur early.

OBJECTIVE

This systematic review and meta-analysis was conducted to summarize the association between high homocysteine levels and traditional cardiovascular risk factors in children and adolescents.

DATA SOURCES

This systematic review and meta-analysis were developed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the protocol was submitted to PROSPERO. Only observational studies in children and adolescents with homocysteine levels as an exposure variable and cardiovascular risk factors as outcome variables were included and searched in the following electronic bibliographic databases: PubMed/MEDLINE, Web of Science, Embase, Latin American and Caribbean Literature in Health Sciences, Ovid and Scopus.

DATA EXTRACTION

Two authors independently extracted data from eligible studies. The methodological quality of the studies was assessed using the Newcastle-Ottawa scale.

DATA ANALYSIS

Seven studies were included in the systematic review; they were published from 1999 to 2017, predominantly were of a cross-sectional design, and mainly evaluated adolescents. In the meta-analysis (n = 6), cross-sectional studies (n = 3) identified that high homocysteine levels were positive and weakly correlated with overweight in children and adolescents (odds ratio, 1.08; 95%CI, 1.04-1.11).

CONCLUSION

High homocysteine levels were weakly associated with overweight in children and adolescents in the reviewed cross-sectional studies. However, for the other traditional cardiovascular risk factors, the findings, although important, were inconclusive. Additional robust longitudinal studies are recommended to be conducted to better identify these associations.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42018086252.

Nutritional management of diabetes mellitus during the pandemic of COVID-19: a comprehensive narrative review

Objectives

According to the recent epidemiological studies, patients with diabetes mellitus (DM) may be at higher risk of hospitalization due to COVID-19. Regarding the important role of nutrition on the immunity, the present review article aimed to outline nutritional support of DM during the outbreak of COVID-19 with a mechanistic insight.

Methods

Searches were performed in PubMed/MEDLINE, ScienceDirect, Scopus, and Google Scholar databases from 2000 until December 2020 using the following keywords. All relevant clinical and experimental studies published in English were included.

Results

Evidences revealed that hyperglycemia is a significant predictor of some viral infections including COVID-19 which can exacerbate the complications of DM. According to the literature review, adequate intake of dietary protein, fiber, essential fatty acids and some micronutrients especially vitamins D, C, B12, folate, zinc and selenium has beneficial effects on the prevention and treatment of COVID-19 in diabetic patients through modulation of innate and adaptive immune responses or direct effects on virus enzymes or the rate of cell entrance.

Conclusions

It is well understood that malnutrition may increase susceptibility to viral infections and disease progression. Therefore, considering nutritional status of diabetic patients and reasonable supplementation of the above mentioned nutrients can ameliorate the symptoms of COVID-19 in DM. However, further well-designed clinical trials are needed to determine their therapeutic dose.

Lactobacillus Sps in Reducing the Risk of Diabetes in High-Fat Diet-Induced Diabetic Mice by Modulating the Gut Microbiome and Inhibiting Key Digestive Enzymes Associated with Diabetes

Simple Summary

Type 2 diabetes (T2D) is increasingly spreading across the globe. The disease is linked to a disruption of gut microbiome. Probiotics are essential gut microbiota modulators proven to restore microbiota changes, thereby conferring health to its host. This study aimed to use probiotics (lactobacilli) and their metabolites as natural anti-diabetic therapy through the modulation of gut microbiota and inhibit diabetes-causing enzymes. Lactobacillus-treated high-fat diet mice showed lower blood glucose levels and body weight. Interestingly, our study also proved that the lactobacilli altered gut microbiota composition by suppressing opportunistic bacteria that are highly associated with metabolic diseases. Our findings substantiate the use of probiotics as natural anti-diabetic therapeutics.

Abstract

Obesity caused by a high-fat diet (HFD) affects gut microbiota linked to the risk of type-2 diabetes (T2D). This study evaluates live cells and ethanolic extract (SEL) of Lactobacillus sakei Probio65 and Lactobacillus plantarum Probio-093 as natural anti-diabetic compounds. In-vitro anti-diabetic effects were determined based on the inhibition of α-glucosidase and α-amylase enzymes. The SEL of Probio65 and Probio-093 significantly retarded α-glucosidase and α-amylase enzymes (p < 0.05). Live Probio65 and Probio-093 inhibited α-glucosidase and α-amylase, respectively (p < 0.05). In mice fed with a 45% kcal high-fat diet (HFD), the SEL and live cells of both strains reduced body weight significantly compared to HFD control (p < 0.05). Probio-093 also improved blood glucose level compared to control (p < 0.05). The gut microbiota modulatory effects of lactobacilli on HFD-induced diabetic mice were analyzed with qPCR method. The SEL and live cells of both strains reduced phyla Deferribacteres compared to HFD control (p < 0.05). The SEL and live cells of Probio-093 promoted more Actinobacteria (phyla), Bifidobacterium, and Prevotella (genus) compared to control (p < 0.05). Both strains exerted metabolic-modulatory effects, with strain Probio-093 showing more prominent alteration in gut microbiota, substantiating the role of probiotics in gut microbiome modulations and anti-diabetic effect. Both lactobacilli are potential candidates to lessen obesity-linked T2D.

Profiling immuno-metabolic mediators of vitamin B12 deficiency among metformin-treated type 2 diabetic patients in Ghana

BACKGROUND

The association between prolong metformin usage and B12 deficiency has been documented. However, the prevalence estimates of metformin-induced vitamin B12 deficiency showed substantial disparity among studies due to varied study definitions of vitamin B12 deficiency. Metformin blocks the calcium dependent absorption of the vitamin B12-Intrinsic Factor complex at the terminal ileum. Lack of intrinsic factor due to the presence of auto-antibodies to parietal cells (IFA) could lead to vitamin B12 deficiency and subsequently cause peripheral neuropathy. We investigated the prevalence of vitamin B12 deficiency using more sensitive, combined markers of vitamin B12 status (4cB12) and the immuno-biochemical mediators of vitamin B12 deficiency.

METHODS

In this observational study, 200 consecutive consenting metformin-treated T2DM patients, aged 35 and above, attending the diabetic clinic at KATH were recruited. Vitamin B12 deficiency was classified based on the Fedosov age-normalized wellness quotient. Anthropometric measurement was taken as well as blood samples for immunological and biochemical mediators. Peripheral neuropathy was assessed using the Michigan Neuropathy Screening Instrument (MNSI). Statistical analysis was performed using the R Language for Statistical Computing.

RESULTS

Using the combined indicator (4cB12), the prevalence of metformin induced vitamin B12 deficiency was 40.5% whilst the prevalence of MNSI-Q and MNSI-PE diabetic neuropathy was 32.5% and 6.5% respectively. Participants with vitamin B12 deficiency had significantly higher levels of IFA, GPA, TNF-α, TC, LDL and albumin compared to those with normal vitamin B12 levels (p < 0.05). Correlation analysis revealed a statistically significant negative association between 4cB12 and the immunological markers [IFA (rs = -0.301, p<0.0001), GPA (rs = -0.244, p = 0.001), TNF-α (rs = -0.242, p = 0.001) and IL-6 (rs = -0.145, p = 0.041)]. Likewise, 4cB12 was negatively associated with TC (rs = -0.203, p = 0.004) and LDL (rs = -0.222, p = 0.002) but positively correlated with HDL (rs = 0.196, p = 0.005).

CONCLUSION

Vitamin B12 deficiency and diabetic neuropathy are very high among metformin-treated T2DM patients and it is associated with increased GPA, IFA, TNF-α and cardiometabolic risk factors (higher LDL and TC and lower HDL). Upon verification of these findings in a prospective case-control study, it may be beneficial to include periodic measurement of Vitamin B12 using the more sensitive combined indicators (4cB 12) in the management of patients with T2DM treated with metformin in Ghana.

A New Approach for Dry Eye Management By Mucoadhesive In situ Gel of Vitamin B12: Formulation, In vitro and In vivo Assessment

The commitment of the existent study was to develop a mucoadhesive in situ gel systems of vitamin B12 for the management of dry eye disease. The gels were prepared using pluronic F-127 and either of chitosan, carbapol 971P, sodium alginate, or hydroxy propyl methyl cellulose. Drug-excipients compatibility was investigated by means of differential scanning calorimetry and Fourier transform infrared spectroscopy. The gels were characterized for pH, clarity, gelling capacity, viscosity, and adhesion. In vitro release of vitamin B12 from the selected gels was investigated. In vivo effectiveness of the selected gel was determined in rabbit models using Schirmer's and fluorescein tests. The compatibility studies revealed the possibility of incidence of drug/polymer interaction in some formulations. F2-containing pluronic F127 and hydroxypropyl methyl cellulose showed the most appropriate physical characterization and in vitro release profile. The prepared gels showed prolonged drug release with drug release mechanism of combined diffusion and erosion. The in vivo study revealed good effectiveness of the prepared mucoadhesive in situ gel system of vitamin B12 in the treatment of dry eye disease that was comparable to that of the marketed drops.

Efficacy of Hyperbaric Oxygen Therapy on Central Corneal Thickness, Intraocular Pressure, and Nerve Fiber Layer in Patients with Type 2 Diabetes: A Prospective Cohort Study

PURPOSE

To evaluate the effect of hyperbaric oxygen therapy (HBOT) on central corneal thickness (CCT), intraocular pressure (IOP), and the retinal nerve fiber layer (RNFL) thickness in patients with type 2 diabetes mellitus.

METHODS

This prospective non-randomized cohort study consisted of type 2 diabetes mellitus patients who received 30 sessions of HBOT for diabetic foot ulcer. The CCT, IOP, and RNFL measured at baseline, after the 10th session of HBOT, after the 20th session of HBOT, after the 30th session of HBOT, and after the 3 months of the last session of HBOT. We gained the superior-nasal, superior-temporal, inferior-nasal, inferior-temporal, nasal and temporal quadrant RNFL values with a spectral-domain optical coharence tomography.

RESULTS

Forty-six eyes of 46 patients included in the study. During the study period, a statistically significant increase in mean IOP values compared to baseline was observed (p < 0.001). We found no significant changes at CCT and all quadrants of RNFL values during HBOT and after 3 months of the treatment (p > 0.05). During the study period, the IOP levels increased over 21 mmHg (between 22 and 28 mmHg) in seven eyes (15.2%). The mean hemoglobin A1c values of these patients with IOP >21 mmHg were 8.2 ± 0.9 mg/dL, and there was significant differences compared with those of patients with IOP values ≤21 mmHg (7.4 ± 2.8 mg/dL) (p = 0.001).

CONCLUSIONS

HBOT increase IOP in type 2 diabetic patients especially in ones with impaired blood glucose regulation. However, it does not cause any changes in CCT and RNFL. As diabetic retinopathy and diabetic foot ulcer are in common pathologies, thus this brief report concludes a need for further studies with longer follow-up periods to explore the potential interaction of HBOT on CCT, IOP, and RNFL.

The effect of vitamin B12 supplement on post-thaw motility, viability and DNA damage of human sperm

Sperm cryopreservation may lead to adverse effects on sperm structure and function. Cyanocobalamin (vitamin B12) has antioxidant potential and can protect DNA from free radical-induced damages. Recent studies have shown that vitamin B12 preserves glutathione that leads to modulate oxidative stress responses. Also, vitamin B12 might act directly as a scavenger of ROS. The aim of this study was to investigate the effects of vitamin B12 supplementation on human sperm parameters during the cryopreservation process. Thirty semen samples were obtained from normozoospermic men. Using cryopreservation medium supplemented with different concentrations of vitamin B12 (0, 0.5, 1, 2, 2.5 mg/ml), the semen samples were cryopreserved. After thawing, all samples were evaluated for motility and viability. Based on results, 2 mg/ml was considered as the optimal concentration of vitamin B12 for evaluating sperm DNA fragmentation. The results showed that 1 and 2 mg/ml vitamin B12 significantly increased post-thawing motility and viability compared with the 0 mg/ml vitamin B12 (p < .05). Also, by supplementing with 2 mg/ml vitamin B12, DNA fragmentation decreased when compared to the control. The present study showed that cryopreservation medium supplemented with vitamin B12 at 2 mg/ml could improve sperm quality after freeze-thaw process.

Intakes of Folate, Vitamin B6, and Vitamin B12 in Relation to Diabetes Incidence Among American Young Adults: A 30-Year Follow-up Study

OBJECTIVE

To prospectively examine intakes of folate, vitamin B₆, and vitamin B₁₂ in relation to diabetes incidence in a large U.S. cohort.

RESEARCH DESIGN AND METHODS

A total of 4,704 American adults aged 18-30 years and without diabetes were enrolled in 1985-1986 and monitored until 2015-2016 in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Dietary assessment was conducted by a validated dietary history questionnaire at baseline, in 1992-1993, and in 2005-2006. The cumulative average intakes of folate, vitamin B₆, and vitamin B₁₂ were used in the analyses. Incident diabetes was ascertained by plasma glucose levels, oral glucose tolerance tests, hemoglobin A_1c concentrations, and/or antidiabetic medications.

RESULTS

During 30 years (mean 20.5 ± 8.9) of follow-up, 655 incident cases of diabetes occurred. Intake of folate, but not vitamin B₆ or vitamin B₁₂, was inversely associated with diabetes incidence after adjustment for potential confounders. Compared with the lowest quintile of total folate intake, the multivariable-adjusted hazard ratios (95% CI) in quintiles 2-5 were 0.85 (0.67-1.08), 0.78 (0.60-1.02), 0.82 (0.62-1.09), and 0.70 (0.51-0.97; P _trend = 0.02). Higher folate intake was also associated with lower plasma homocysteine (P _trend < 0.01) and insulin (P _trend < 0.01). Among supplement users, folate intake was inversely associated with serum C-reactive protein levels (P _trend < 0.01).

CONCLUSIONS

Intake of folate in young adulthood was inversely associated with diabetes incidence in midlife among Americans. The observed association may be partially explained by mechanisms related to homocysteine level, insulin sensitivity, and systemic inflammation.

Genetic variants in glutamate cysteine ligase confer protection against type 2 diabetes

Oxidative stress contributes to the pathogenesis of type 2 diabetes (T2D). This study investigated whether single nucleotide polymorphisms (SNPs) at genes encoding glutamate cysteine ligase catalytic (rs12524494, rs17883901, rs606548, rs636933, rs648595, rs761142 at GCLC) and modifier (rs2301022, rs3827715, rs7517826, rs41303970 at GCLM) subunits are associated with susceptibility to type 2 diabetes. 2096 unrelated Russian subjects were enrolled for the study. Genotyping was done with the use of the MassArray System. Plasma levels of reactive oxygen species (ROS) and glutathione in the study subjects were analyzed by fluorometric and colorimetric assays, respectively.The present study found, for the first time, an association of SNP rs41303970 in the GCLM gene with a decreased risk of T2D (P = 0.034, Q = 0.17). Minor alleles such as rs12524494-G GCLC gene (P = 0.026, Q = 0.17) and rs3827715-C GCLM gene (P = 0.03, Q = 0.17) were also associated with reduced risk for T2D. Protective effects of variant alleles such as rs12524494-G at GCLC (P = 0.02, Q = 0.26) and rs41303970-A GCLM (P = 0.013, Q = 0.25) against the risk of T2D were seen solely in nonsmokers. As compared with healthy controls, diabetic patients had markedly increased levels of ROS and decreased levels of total GSH in plasma. Interestingly, fasting blood glucose level positively correlated with oxidized glutathione concentration (r_s = 0.208, P = 0.01). Three SNPs rs17883901, rs636933, rs648595 at GCLC and one rs2301022 at GCLM were associated with decreased levels of ROS, while SNPs rs7517826, rs41303970 at GCLM were associated with increased levels of total GSH in plasma. Single nucleotide polymorphisms in genes encoding glutamate cysteine ligase subunits confer protection against type 2 diabetes and their effects are mediated through increased levels of glutathione.

Two Cultivars of <i>Ocimum basilicum</i> Leaves Extracts Attenuate Streptozotocin-mediated Oxidative Stress in Diabetic Rats

BACKGROUND AND OBJECTIVE

Leaves of basil plant (Ocimum basilicum) are often used for medicinal purposes because of their bioactive constituents, yet the antioxidant properties of this plant are not fully studied in the field of diabetes. The present study investigated the antioxidant property and anti-diabetic effect of two basil cultivars of Ocimum basilicum, 'Italian Genovese' and 'Thyrsiflora', in a Streptozotocin (STZ) rat model of diabetes .

MATERIALS AND METHODS

Sixty adult Sprague Dawley rats (n = 10/group) were divided into 6 groups: Three non-diabetic and three diabetic groups that either did not receive any supplementation or were supplemented with the leaves extract of one or the other cultivar. After 13 weeks of feeding, all rats were sacrificed, pancreatic tissues were homogenized and used for evaluating oxidative DNA damage and dichlorofluorescein fluorescence (DCF) assay. Blood was collected for the measurements of glucose and insulin.

RESULTS

The STZ caused oxidative stress in the diabetic group as evidenced by an increase in oxidative DNA damage and also caused DCF production in pancreatic tissues as compared to non-diabetic groups, (p<0.05). The STZ treatment resulted in hyperglycemia and low serum insulin level in diabetic rats. Supplementation with extracts of 'Italian Genovese' and 'Thyrsiflora' to the diabetic groups significantly abrogated the STZ-mediated effects (p<0.05).

CONCLUSION

The results indicated that the extracts from the leaves of the two examined basil cultivars act as potent antioxidants and combat the STZ-mediated diabetogenic effect.

Hierarchical structural component model for pathway analysis of common variants

BACKGROUND

Genome-wide association studies (GWAS) have been widely used to identify phenotype-related genetic variants using many statistical methods, such as logistic and linear regression. However, GWAS-identified SNPs, as identified with stringent statistical significance, explain just a small portion of the overall estimated genetic heritability. To address this 'missing heritability' issue, gene- and pathway-based analysis, and biological mechanisms, have been used for many GWAS studies. However, many of these methods often neglect the correlation between genes and between pathways.

METHODS

We constructed a hierarchical component model that considers correlations both between genes and between pathways. Based on this model, we propose a novel pathway analysis method for GWAS datasets, Hierarchical structural Component Model for Pathway analysis of Common vAriants (HisCoM-PCA). HisCoM-PCA first summarizes the common variants of each gene, first at the gene-level, and then analyzes all pathways simultaneously by ridge-type penalization of both the gene and pathway effects on the phenotype. Statistical significance of the gene and pathway coefficients can be examined by permutation tests.

RESULTS

Using the simulation data set of Genetic Analysis Workshop 17 (GAW17), for both binary and continuous phenotypes, we showed that HisCoM-PCA well-controlled type I error, and had a higher empirical power compared to several other methods. In addition, we applied our method to a SNP chip dataset of KARE for four human physiologic traits: (1) type 2 diabetes; (2) hypertension; (3) systolic blood pressure; and (4) diastolic blood pressure. Those results showed that HisCoM-PCA could successfully identify signal pathways with superior statistical and biological significance.

CONCLUSIONS

Our approach has the advantage of providing an intuitive biological interpretation for associations between common variants and phenotypes, via pathway information, potentially addressing the missing heritability conundrum.

Telomere length, vitamin B12 and mortality in persons undergoing coronary angiography: the Ludwigshafen risk and cardiovascular health study

Background: Vitamin B12 (B12) deficiency and excess are associated with increased risk of age-related-diseases and mortality. It has been suggested that high- and low-B12 concentrations link to increased mortality through accelerated genomic aging and inflammation. Evidence to support this is limited.

Results: B12 was associated with all-cause-mortality, RTL and hsCRP in a non-linear fashion. The association between B12 and mortality was not independent, as it lost significance after adjustment for potential confounders. In the lowest-(LB12) and highest-(HB12) quartiles of B12 mortality was higher than in the mid-range (HR:LB12:1.23;CI95%:1.06-1.43; HR:HB12:1.24;CI95%:1.06-1.44). We divided subjects with LB12 in quartiles of their RTL. Those with the longest-telomeres had a lower mortality-rate (HR:0.57;95%CI:0.39-0.83) and lower homocysteine than those with the shortest-telomeres. Amongst subjects with HB12, those with long-telomeres also had a lower mortality than those with short-telomeres (HR:0.40;95%CI:0.27-0.59). IL-6 and hsCRP concentrations were low in HB12LT but were high in HB12ST.

Methods: B12, homocysteine, telomere length (RTL), interleukin-6 (IL-6) and high-sensitive-C-reactive-protein (hsCRP) were measured in 2970 participants of the LURIC study.

Conclusions: Mortality, stratified according to B12 and RTL, seems to be driven by different mechanisms. In LB12 and HB12 subjects, mortality and accelerated telomere shortening might be driven by homocysteine and inflammation, respectively.

Deciphering the Link Between Hyperhomocysteinemia and Ceramide Metabolism in Alzheimer-Type Neurodegeneration

Aging is one of the strongest risk factor for Alzheimer's disease (AD). However, several data suggest that dyslipidemia can either contribute or serve as co-factors in AD appearance. AD could be examined as a metabolic disorder mediated by peripheral insulin resistance. Insulin resistance is associated with dyslipidemia, which results in increased hepatic ceramide generation. Hepatic steatosis induces pro-inflammatory cytokine activation which is mediated by the increased ceramides production. Ceramides levels increased in cells due to perturbation in sphingolipid metabolism and upregulated expression of enzymes involved in ceramide synthesis. Cytotoxic ceramides and related molecules generated in liver promote insulin resistance, traffic through the circulation due to injury or cell death caused by local liver inflammation, and because of their hydrophobic nature, they can cross the blood-brain barrier and thereby exert neurotoxic responses as reducing insulin signaling and increasing pro-inflammatory cytokines. These abnormalities propagate a cascade of neurodegeneration associated with oxidative stress and ceramide generation, which potentiate brain insulin resistance, apoptosis, myelin degeneration, and neuro-inflammation. Therefore, excess of toxic lipids generated in liver can cause neurodegeneration. Elevated homocysteine level is also a risk factor for AD pathology and is narrowly associated with metabolic diseases and non-alcoholic fatty liver disease. The existence of a homocysteine/ceramides signaling pathway suggests that homocysteine toxicity could be partly mediated by intracellular ceramide accumulation due to stimulation of ceramide synthase. In this article, we briefly examined the role of homocysteine and ceramide metabolism linking metabolic diseases and non-alcoholic fatty liver disease to AD. We therefore analyzed the expression of mainly enzymes implicated in ceramide and sphingolipid metabolism and demonstrated deregulation of de novo ceramide biosynthesis and S1P metabolism in liver and brain of hyperhomocysteinemic mice.

The concomitant lower concentrations of vitamins B6, B9 and B12 may cause methylation deficiency in autistic children

Autism spectrum disorder (ASD) is characterized by severe and persistent difficulties in social communication and social interaction at multiple levels. Recently, metabolic disorders have been associated with most cases of patients with ASD. The aim of this study was to investigate, through a new and more sophisticated mass technique, such as UHPLC-mass spectrometry (Q-exactive analyzer), alteration in metabolisms analyzing ASD children urine samples from children showing simultaneous vitamin B6, B9 and B12 deficiencies. This in order to study how these concurrent deficiencies may influence some phenotypic aspects of autistic disorder. Thus, urinary metabolic patterns specific to ASD were explored at an early age in 60 children with ASD, showing lower three vitamins levels, and 60 corresponding controls (age group 3-8, M: F=42:18). The results showed significant block of cystathionine formation with consequent accumulation of homocysteine. A lower glutathione levels (GSH), with reduction of essential intracellular reducing environment required for normal immune function, detoxification capacity and redox-sensitive enzyme activity. Increased concentration of 5-methyltetrahydrofolate, which leads to a lower availability of methyl group and significant decrease in urinary methionine and S-adenosyl-L-methionine (SAM) concentrations, the major methyl donor. The latter justify the well-known reduction in protein and DNA methylation reported in autistic children. As a final consideration, the concomitant deficiencies of all three B vitamins, recorded in a significant number of autistic children, suggests that intestinal dysbiosis in these patients may be the main cause of a reduction in their absorption, in addition to the genetic mutation of a specific gene.

[Oxidative stress correction in the treatment of severe keratoconjunctivitis sicca in patients with Sjorgen's syndrome]

PURPOSE

To evaluate the antioxidative effect of artificial tears in the treatment of keratoconjunctivitis sicca (KCS).

MATERIAL AND METHODS

The study included 43 patients (60 eyes) with severe KCS: 38 women (50 eyes) and 5 men (10 eyes) aged from 27 to 76 years (in average 52 years). Patients were randomly divided into 2 groups; all patients used therapeutic silicone hydrogel soft contact lens (SCL) and instillations of 0.05% Cyclosporin A (CyA) 2 times a day. Patients of the first group (22 people, 30 eyes) used 0.15% hyaluronic acid. In the second group, patients (21 people, 30 eyes) used a tear substitute with similar surface-active component, but with antioxidant properties. The results of the treatment were evaluated using basic and additional research methods at 1, 3, 6 and 12 months.

RESULTS

Corneal epithelialization was achieved after 1 month of conservative treatment in all patients who wore SCLs and were treated with instillations of 0.05% CyA and artificial tears. Then the lenses were removed and the patients were switched to instillations of CyA and artificial tears. Comparative analysis of the results showed that higher functional indicators were achieved in the second group, where patients used Artelac Rebalance drops with antioxidant properties.

CONCLUSION

Improvement of clinical and functional parameters in the treatment of severe forms of KCS was achieved by direct action on both links of pathogenesis with minimal amounts of the drugs and the frequency of their use. Subsequent supportive therapy contributed to stabilization of the results and further increase of the functional parameters.

Vitamin B12 in Relation to Oxidative Stress: A Systematic Review

The triage theory posits that modest micronutrient deficiencies may induce reallocation of nutrients to processes necessary for immediate survival at the expense of long-term health. Neglected processes could in time contribute to the onset of age-related diseases, in which oxidative stress is believed to be a major factor. Vitamin B12 (B12) appears to possess antioxidant properties. This review aims to summarise the potential antioxidant mechanisms of B12 and investigate B12 status in relation to oxidative stress markers. A systematic query-based search of PubMed was performed to identify eligible publications. The potential antioxidant properties of B12 include: (1) direct scavenging of reactive oxygen species (ROS), particularly superoxide; (2) indirect stimulation of ROS scavenging by preservation of glutathione; (3) modulation of cytokine and growth factor production to offer protection from immune response-induced oxidative stress; (4) reduction of homocysteine-induced oxidative stress; and (5) reduction of oxidative stress caused by advanced glycation end products. Some evidence appears to suggest that lower B12 status is related to increased pro-oxidant and decreased antioxidant status, both overall and for subclinically deficient individuals compared to those with normal B12 status. However, there is a lack of randomised controlled trials and prospective studies focusing specifically on the relation between B12 and oxidative stress in humans, resulting in a low strength of evidence. Further work is warranted.

Adequate or elevated dietary folate does not ameliorate the reduced antioxidant capacity induced by vitamin B12 deficiency in aged rats

Folate could have an antioxidant role but also may be detrimental under vitamin B₁₂ deficiency. The aim was to investigate the effect of different dietary folic acid (FA) levels, on oxidative stress in B₁₂ induced deficient aged rats. Thirty-five male aged Sprague-Dawley rats, were fed either a vitamin B₁₂ deficient (n = 27) or a control diet (n = 8) during eight weeks. Then, animals were divided into four groups: B₁₂ and FA deficient diet (DBDF), B₁₂ deficient diet and FA control diet (DBCF), B₁₂ deficient diet and FA supplemented diet (DBSF), and control diet (CBCF) for a 30 days period. Methionine metabolism and antioxidant status were evaluated. Both vitamins deficiencies elevated serum homocysteine (Hcy) (7.7 vs. 4.3 μmol/L, p < 0.05) and reduced S-adenosylmethionine hepatic content (283.7 vs. 581.9 μg/g protein, p < 0.05), the total antioxidant capacity (155.7 vs. 189.3 μmol/L, p < 0.05), glutathione (GSH) (120.5 vs. 419.9 μg/mg protein, p < 0.05) and oxidized glutathione (0.9 vs. 2.6 μg/mg protein, p < 0.05) compared to control. Activities of glutathione peroxidase and glutathione reductase enzymes or damage to macromolecules were unaffected. Adequate or elevated dietary FA in B₁₂ deficiency rats decreased Hcy (5.7 and 6.3 μmol/L, respectively) and increased total antioxidant capacity (189.8 and 192.6 μmol/L, respectively) to values similar to control group, whereas GSH concentration was significantly lower than control (209.1 and 208.0 μg/mg protein respectively, p < 0.05). In conclusion, in a vitamin B₁₂ deficiency status, adequate or elevated FA prevented impairment in one-carbon metabolism, but does not fully reverse the decrease in antioxidant capacity.