Vascular and cellular stress in inflammatory bowel disease: revisiting the role of homocysteine

Elevated serum homocysteine levels associated with poor recurrence-free and overall survival in patients with colorectal cancer

This study aimed to evaluate the significance of homocysteine (HCY) levels in predicting recurrence-free survival (RFS) and overall survival (OS) in colorectal cancer (CRC) patients. This retrospective study involved 1272 CRC patients. The risk of mortality increased with increasing HCY levels in CRC patients. The optimal HCY cutoff value in CRC patients was 15.2 μmol/L. The RFS (45.8% vs. 60.5%, p < 0.001) and OS (48.2% vs. 63.2%, p < 0.001) of patients with high HCY levels were significantly lower than those of patients with low HCY levels. Patients with high HCY levels were older, male, had large tumours, high carcinoembryonic antigen (CEA) levels, and long hospital stays, and incurred high hospitalisation costs. Multivariate analysis showed that when HCY levels exceeded 15.2 μmol/L, the risk of adverse RFS and OS increased by 55.7% and 61.4%, respectively. Subgroup analysis showed that HCY levels could supplement CEA levels and pathological staging. We constructed HCY-based prognostic nomograms, which demonstrated feasible discrimination and calibration values better than the traditional tumour, node, metastasis staging system for predicting RFS and OS. Elevated serum HCY levels were strongly associated with poor RFS and OS in CRC patients. HCY-based prognostic models are effective tools for a comprehensive evaluation of prognosis.

Serum homocysteine level was elevated in ulcerative colitis and can be applied as diagnostic biomarker

Objective

To investigate the correlation between serum level of homocysteine (Hcy) and ulcerative colitis (UC) and evaluate its diagnostic performance by pooling the open published data.

Methods

The case–control or cohort studies relevant to serum level of Hcy and UC, published in Pubmed, Medline, EMBASE, China Wanfang and CNKI databases, were systematically screened by using the text word of “homocysteine,” “hcy,” “UC,” “inflammatory bowel disease.” The standard mean difference (SMD) was pooled through random effect model. The diagnostic sensitivity, specificity and area under the receiver operating characteristic (AUC) curve of serum Hcy for UC were also calculated.

Results

Eighteen relevant case–control studies were identified by electronic searching the related databases. The pooled results indicated that the serum levels of Hcy were statical different between UC and healthy controls with SMD = 0.95 (95% CI: 0.87–1.04). The serum levels of Hcy were 14.30 ± 3.08 (range: 10.10–21.73) and 10.09 ± 1.57 (range: 6.80–12.47) μmol/L for UC and healthy controls, respectively, of the included 18 studies. Using serum Hcy as biomarker for UC identification, the diagnostic sensitivity, specificity and AUC were 94.44% (95% CI: 72.71–99.86%), 72.22% (46.52–90.31%) and 0.88 (95% CI: 0.77–0.99, P < 0.05), respectively. Significant publication bias was identified in the present work.

Conclusion

Based on the present publications, serum Hcy was elevated in UC cases and can be applied as serological marker for UC diagnosis. However, due to significant publication bias, the diagnostic performance should be further validated by well-designed prospective diagnostic studies.

The methylenetetrahydrofolate reductase 1298 A>C polymorphism is associated with an increased risk of inflammatory bowel disease: evidence from a meta-analysis

OBJECTIVE

The association between genetic variants in methylenetetrahydrofolate reductase (MTHFR) and risk for inflammatory bowel disease (IBD) has been widely studied. However, the results are equivocal. In this meta-analysis, we aimed to determine the association between MTHFR polymorphisms and susceptibility to IBD.

METHODS

We retrieved studies from the PubMed, Web of Science, Ovid, and China National Knowledge Infrastructure databases. Data were analyzed using STATA software; odds ratios (OR) and confidence intervals (CI) were calculated using fixed or random effects models.

RESULTS

A marginally significant association of the MTHFR 677 C > T polymorphism and patients' IBD risk was observed in the overall analysis (OR = 1.11, 95% CI, 1.01-1.23), but not in the analysis of high-quality studies. However, for the MTHFR 1298 A > C polymorphism, a significant association was found between the MTHFR 1298 AC/CC genotypes and IBD risk in the overall analysis (OR = 1.26, 95% CI, 1.10-1.44), in the high-quality studies (OR = 1.20, 95% CI, 1.02-1.41), and in patients with ulcerative colitis (OR = 1.28, 95% CI, 1.10-1.48).

CONCLUSIONS

Evidence from this meta-analysis indicates that the MTHFR 1298 A > C polymorphism may be responsible for susceptibility to IBD and ulcerative colitis.

Vitamin B12 Deficiency Alters the Gut Microbiota in a Murine Model of Colitis

Purpose: Inflammatory bowel disease (IBD) refers to a spectrum of autoimmune diseases, which result in chronic intestinal inflammation. Previous findings suggest a role for diet, nutrition and dysbiosis of the gut microbiota in both the development and progression of the condition. Vitamin B12 is a key cofactor of methionine synthase and is produced solely by microbes. Previous work links increased levels of homocysteine, a substrate of methionine synthase, MetH, to IBD indicating a potential role for vitamin B12 deficiency in intestinal injury and inflammation. This study assessed the role of vitamin B12 in shaping the gut microbiota and determining responses to intestinal injury using a reproducible murine model of colitis. Methods: The effects of vitamin B12 supplementation and deficiency were assessed in vivo; 3-week-old post-weanling C57Bl/6 mice were divided into three dietary treatment groups: (1) sufficient vitamin B12 (50 mg/Kg), (2) deficient vitamin B12 (0 mg/Kg) and (3) supplemented vitamin B12 (200 mg/Kg) for a period of 4 weeks. Intestinal injury was induced with 2% dextran sodium sulphate (DSS) via drinking water for 5 days. The impact of varying levels of dietary vitamin B12 on gut microbiota composition was assessed using 16S rRNA gene sequencing from fecal samples collected at day 0 and day 28 of the dietary intervention, and 7 days following induction of colitis on day 38, when blood and colonic tissues were also collected. Results: No significant alterations were found in the gut microbiota composition of disease-free animals in response to dietary interventions. By contrast, after DSS-induced colitis, >30 genera were significantly altered in vitamin B12 deficient mice. Altered B12 levels produced no significant effect on composite disease-activity scores; however, administration of a B12 deficient diet resulted in reduced DSS-induced epithelial tissue damage. Conclusions: Vitamin B12 supplementation does not alter the gut microbiota composition under healthy conditions, but does contribute to differential microbial responses and intestinal dysbiosis following the induction of experimental colitis.

The deficit in folate and vitamin B12 triggers liver macrovesicular steatosis and inflammation in rats with dextran sodium sulfate-induced colitis

The risks of nonalcoholic steatohepatitis (NASH) and deficiency in vitamin B12 and folate (methyl donor deficiency, MDD) are increased in inflammatory bowel disease (IBD). We investigated the influence of MDD on NASH in rats with DSS-induced colitis. Two-month-old male Wistar rats were subjected to MDD diet and/or ingestion of DSS and compared to control animals. We studied steatosis, inflammation, fibrosis, plasma levels of metabolic markers, cytokines and lipopolysaccharide, and inflammatory pathways in liver. MDD triggered a severe macrovesicular steatosis with inflammation in DSS animals that was not observed in animals subjected to DSS or MDD only. The macrovesicular steatosis was closely correlated to folate, vitamin B12, homocysteine plasma level and liver S-adenosyl methionine/S-adenosyl homocysteine (SAM/SAH) ratio. Liver inflammation was evidenced by activation of nuclear factor kappa B (NFκB) pathway and nuclear translocation of NFκB phospho-p65. MDD worsened the increase of interleukin 1-beta (IL-1β) and abolished the increase of IL10 produced by DSS colitis. It increased monocyte chemoattractant protein 1 (MCP-1). MDD triggers liver macrovesicular steatosis and inflammation through imbalanced expression of IL-1β vs. IL10 and increase of MCP-1 in DSS colitis. Our results suggest evaluating whether IBD patients with MDD and increase of MCP-1 are at higher risk of NASH.

Effect of a Nutrition Support Formula in Adults With Inflammatory Bowel Disease: A Pilot Study

Background

Due to the high prevalence of nutrient deficiencies in patients with inflammatory bowel disease (IBD), routine monitoring of nutrient status and supplementation are recommended.

Objective

This preliminary study was implemented to prospectively identify potential effects of a nutrition support formula on blood nutrient parameters in adults with IBD.

Methods

Ten adults with Crohn’s disease or ulcerative colitis were recruited from the Portland, Oregon, metropolitan area into a single-arm, open-label pilot study. Participants consumed a nutrition support beverage twice daily for 12 weeks. The formula contained a mixture of micronutrients (including methylated forms of folate and vitamin B12), macronutrients, and phytonutrients (including curcumin, xanthohumol, ginger compounds, and quercetin). Primary measures were the following parameters: folate, vitamin B12, red blood cell (RBC) count, hemoglobin, hematocrit, electrolytes, and albumin. Exploratory measures included a food frequency questionnaire, circulating blood cell counts, and inflammatory markers.

Results

Nine participants completed the study and one withdrew. Adherence was 98%. Serum folate increased 48.7% (P = .029), serum vitamin B12 increased 17.4% but did not reach statistical significance (P = .053), and red cell distribution width (RDW) decreased 9.2% (P = .012) over the 12-week study period. There were minimal shifts in total white blood cell (WBC) counts (−1.0%, P = .845), but percent neutrophils decreased 10.4% (P = .042) and absolute lymphocyte count increased 18.6% (P = .048). RBC count, hemoglobin, hematocrit, electrolytes, albumin, and inflammatory markers did not change significantly. Post hoc analysis demonstrated that neutrophil–lymphocyte ratio (NLR) decreased 18.4% (not significant, P = .061).

Conclusion

Serum folate and RDW improved in adults with IBD after 12 weeks. Modulation of leukocyte subtypes was also observed, including a decrease in neutrophils and an increase in lymphocytes, with no change in total WBC count. A randomized, controlled study to further examine effects of the nutrition support formula will be initiated to follow up on this promising, but preliminary investigation.

Distinct biomarkers for different bones in osteoporosis with rheumatoid arthritis

Background

Rheumatoid arthritis (RA) is known to cause secondary osteoporosis and fragility fractures. This study aimed to identify biomarkers predictive of bone mineral density (BMD) change at three anatomical sites in patients with RA.

Methods

We conducted a prospective longitudinal study in patients with RA. In 2012, we recruited 379 patients from an RA cohort, 329 of whom underwent evaluation of blood and urine biomarkers together with measurement of BMD in the lumbar spine, proximal femur, and distal forearm. The BMD in these three regions was reassessed in 2014. We performed multivariate linear regression analysis to identify those factors associated with BMD change.

Results

The averages of age, body mass index, and disease activity score in 28 joints (DAS28) at baseline were 63.2 (minimum to maximum, 32–85), 21.3 (12.3–30.0), and 3.2 (0.1–5.9), respectively. Univariate analysis showed that the annual BMD change was significantly associated with the use of steroid, bisphosphonate (BP) or vitamin D (VitD), and serum homocysteine in the lumber spine; DAS28, the use of BP or VitD, CRP, and anti-cyclic citrullinated peptide antibody (ACPA) in the proximal femur; and the dosage of MTX, the use of BP or VitD, and serum tartrate-resistant acid phosphatase 5b (TRACP-5b) in the distal forearm, respectively.

Conclusions

Predictive biomarkers for BMD change in RA patients differ at each anatomical site. Practitioners should treat each anatomical site with different markers and prescribe osteoporosis drugs to prevent fractures for RA patients.

Global Burden Related to Nitrous Oxide Exposure in Medical and Recreational Settings: A Systematic Review and Individual Patient Data Meta-Analysis

The risk of adverse effects of nitrous oxide (N₂O) exposure is insufficiently recognized despite its widespread use. These effects are mainly reported through case reports. We conducted an individual patient data meta-analysis to assess the prevalence of clinical, laboratory, and magnetic resonance findings in association with N₂O exposure in medical and recreational settings. We calculated the pooled estimates for the studied outcomes and assessed the potential bias related to population stratification using principal component analysis. Eighty-five publications met the inclusion criteria and reported on 100 patients with a median age of 27 years and 57% of recreational users. The most frequent outcomes were subacute combined degeneration (28%), myelopathy (26%), and generalized demyelinating polyneuropathy (23%). A T2 signal hyperintensity in the spinal cord was reported in 68% (57.2–78.8%) of patients. The most frequent clinical manifestations included paresthesia (80%; 72.0–88.0%), unsteady gait (58%; 48.2–67.8%), and weakness (43%; 33.1–52.9%). At least one hematological abnormality was retrieved in 71.7% (59.9–83.4%) of patients. Most patients had vitamin B12 deficiency: vitamin B12 <150 pmol/L (70.7%; 60.7–80.8%), homocysteine >15 µmol/L (90.3%; 79.3–100%), and methylmalonic acid >0.4 µmol/L (93.8%; 80.4–100%). Consistently, 85% of patients exhibited a possibly or probably deficient vitamin B12 status according to the cB12 scoring system. N₂O can produce severe outcomes, with neurological or hematological disorders in almost all published cases. More than half of them are reported in the setting of recreational use. The N₂O-related burden is dominated by vitamin B12 deficiency. This highlights the need to evaluate whether correcting B12 deficiency would prevent N₂O-related toxicity, particularly in countries with a high prevalence of B12 deficiency.

Effect of Homocysteine on the Differentiation of CD4+ T Cells into Th17 Cells

BACKGROUND

The hyperhomocysteinaemia (Hhcy) is a common phenomenon observed in patients with inflammatory bowel disease (IBD). Our previous study showed that Hhcy aggravated intestinal inflammation in an animal model of colitis. Increased levels of IL-17 and RORγt were also observed in this animal model of colitis with Hhcy. However, the direct effect of homocysteine on the differentiation of Th17 cells has never been studied. The aim of this study was to investigate the direct effect of Hhcy on the differentiation of CD4⁺ T cells into Th17 cells.

METHOD

Lamina propria lymphocytes (LPLs) in colonic mucosa of Wistar rats were isolated and cultured under Th17-inducing (iTH17) environments. Different concentrations of the Hcy (0-100 μmol/ml) were added alone or combined with IL-23 (100 ng/ml) or folate (5 μmol/ml). The LPLs were divided into eight groups as follows: (1) Control group; (2) 10 μmol/ml Hcy group; (3) 25 μmol/ml Hcy group; (4) 50 μmol/ml Hcy group; (5) 100 μmol/ml Hcy group; (6) 100 ng/ml IL-23 group; (7) 50 μmol/ml Hcy + 100 ng/ml IL-23 group and (8) 50 μmol/ml Hcy + 100 ng/ml IL-23 + 5 μmol/ml folate group. The protein expression levels of IL-17, retinoid-related orphan nuclear receptor-γt (RORγt), p38 MAPK, phosphorylated p38 MAPK, cytosolic phospholipase A2 (cPLA2), phosphorylated-cPLA2 and cyclooxygenase 2 (COX2) were detected by immunoblot analysis. The protein level of prostaglandin E2 (PGE2) and IL-17 was detected by ELISA, and IL-17 and RORγt-positive CD4⁺ T cells were stained and analyzed by flow cytometry.

RESULTS

Hcy increased the protein levels of IL-17, RORγt, the ratio of phosphorylated p38 MAPK to p38 MAPK (p-p38/p38), the ratio of phosphorylated cPLA2 to cPLA2 (p-cPLA2/cPLA2) and COX2. The effect was concentration dependent to a certain degree; Hcy of 50 μmol/ml was the optimal concentration to increase the protein levels of those molecules. The level of IL-17 and PGE2 in the cell culture supernatants and the expression of IL-17 and RORγt in positive CD4⁺ T cells were also increased in the group of Hhcy. IL-23 showed a cooperative effect with Hcy on the differentiation of CD4⁺ Th cells into Th17 cells, whereas folate supplementation showed an inhibition action.

CONCLUSIONS

Homocysteine promoted the differentiation of CD4⁺ T cells into Th17 cells in a dose-dependant manner. This effect could be inhibited by folate.

Gene-Metabolite Interaction in the One Carbon Metabolism Pathway: Predictors of Colorectal Cancer in Multi-Ethnic Families

For personalized healthcare, the purpose of this study was to examine the key genes and metabolites in the one-carbon metabolism (OCM) pathway and their interactions as predictors of colorectal cancer (CRC) in multi-ethnic families. In this proof-of-concept study, we included a total of 30 participants, 15 CRC cases and 15 matched family/friends representing major ethnic groups in southern California. Analytics based on supervised machine learning were applied, with the target variable being specified as cancer, including the ensemble method and generalized regression (GR) prediction. Elastic Net with Akaike's Information Criterion with correction (AICc) and Leave-One-Out cross validation GR methods were used to validate the results for enhanced optimality, prediction, and reproducibility. The results revealed that despite some family members sharing genetic heritage, the CRC group had greater combined gene polymorphism-mutations than the family controls (p < 0.1) for five genes including MTHFR C677T, MTHFR A1298C, MTR A2756G, MTRR A66G, and DHFR 19bp. Blood metabolites including homocysteine (7 µmol/L), methyl-folate (40 nmol/L) with total gene mutations (≥4); age (51 years) and vegetable intake (2 cups), and interactions of gene mutations and methylmalonic acid (MMA) (400 nmol/L) were significant predictors (all p < 0.0001) using the AICc. The results were validated by a 3% misclassification rate, AICc of 26, and >99% area under the receiver operating characteristic curve. These results point to the important roles of blood metabolites as potential markers in the prevention of CRC. Future intervention studies can be designed to target the ways to mitigate the enzyme-metabolite deficiencies in the OCM pathway to prevent cancer.

Meta-analysis of homocysteine-related factors on the risk of colorectal cancer

The major objective of this meta-analysis was to examine the association between homocysteine and related measurements with the risk of colorectal cancer (CRC) and adenomatous polyps (AP). Many studies presented an association between methyltetrahydrofolate reductase (MTHFR) gene polymorphisms and risk of CRC. Yet, there have been variances on what homocysteine-related and dietary factors play on the risk of CRC or AP, in association with folate-related one carbon metabolism pathways. We pooled analyses to examine comprehensively all homocysteine related factors including blood tests measurements, dietary, and lifestyle factors for their associations with the risk of CRC and AP. We located 86 articles published from 1995 to 2017. The results revealed that elevated homocysteine levels and decreased vitamin B12 levels in the blood were associated with increased risks of CRC and AP, with case-control studies having greater significant effect sizes compared to that of cohort-control studies. Decreased methionine and vitamin B6 levels in the blood increased the risk of CRC. MTHFR 677 TT and CT polymorphisms were interacting with elevated homocysteine levels to increase the risk of CRC. Decreased dietary fiber, methionine, vitamin B9 or folate, and vitamin B6 intakes were associated with increased risks of CRC; whereas, increased dietary B12 intake, alcohol intake, and smoking were associated with increased risk of CRC. Further studies can be conducted to examine the mechanistic differences of blood levels of homocysteine-related and dietary factors, including different types of dietary fiber, for their effects on decreasing the homocysteine toxicity to prevent CRC.

Vitamin B12 deficiency in inflammatory bowel disease: a prospective observational pilot study

BACKGROUND AND AIM

Diagnostic and management guidelines for vitamin B12 (cobalamin, Cbl) deficiency in inflammatory bowel disease (IBD) are lacking. True deficiency is defined as Cbl concentrations below reference range combined with elevated methylmalonic acid (MMA) concentrations. Studies analyzing Cbl status in IBD use only Cbl concentrations without confirmatory MMA. This study aims to determine the proportion of IBD patients with Cbl concentrations below reference range and their predisposing clinical and genetic characteristics. We then compared this to the proportion with true deficiency.

PATIENTS AND METHODS

In a prospective observational pilot study of adult IBD outpatients, Cbl concentrations, MMA levels, and fucosyltransferase 2 mutations were measured at clinic visits.

RESULTS

A total of 66 Crohn's disease (CD) and 30 ulcerative colitis (UC) patients were recruited. Mean Cbl concentrations (pmol/l) in CD (253.7) were not significantly lower than UC (320.5, P=0.24). Serum Cbl below reference range (<148) was observed in 7.6 and 10% of CD and UC patients, respectively (P=0.70). True deficiency in CD and UC was 3 and 3.3%, respectively (P=1.0). Patients with ileal resections more than 30 cm had lower mean Cbl concentrations (177, P=0.02) and a trend toward higher proportions with Cbl levels below reference range (40%, P=0.06), but not increased deficiency rates (0%, P=1.0). Disease location, severity, and fucosyltransferase 2 mutations were not associated with altered Cbl status.

CONCLUSION

True Cbl deficiency was rare in IBD patients in this study. A disparity in Cbl status exists when confirmatory MMA levels are used compared with Cbl concentrations alone. Asymptomatic IBD patients with low serum Cbl require confirmatory tests to guide management and avoid unnecessary treatment.

Different pathways involved in the stimulatory effects of homocysteine on rat duodenal smooth muscle

Recent studies have confirmed that hyperhomocysteinemia is associated with gastrointestinal diseases; however, the direct effect of homocysteine on gastrointestinal reactivity still remains unknown. The aim of this study was to demonstrate how homocysteine may affect nitric oxide mediated duodenal relaxation and whether cholinergic receptors and K+ channels take part in stimulating motility, as well as to explore whether oxidative stress is associated with homocysteine-mediated effects. Experiments were carried out on male rats, body mass 250-300 g. Two groups of animals were treated by i.p. application of saline and D,L-Hcy (0.6 μmol/g bm). After 2h of incubation, the duodenal segments were prepared for biochemical analysis and contractile response measurements in an organ bath with Tyrode’s solution. Effects of TEA (10 mmol/L) and L-NAME (30 μmol/L) on duodenal contractility in the presence of D,L-Hcy (0.6 μmol/g bm) were investigated. Elevated homocysteine levels seem to be of crucial importance for the deterioration of contractility through nitric oxide mediated relaxation, and, in part, by activation of K+ channels. Hcy showed direct promuscarinic effects, since 30 min pretreatment of rat duodenum significantly enhanced the contractile effect of increasing concentrations of ACh (10−9-10−2 mol/L). Catalase activity, superoxide dismutase, glutathione peroxidase and the total antioxidant system were reduced while the thiobarbituric acid-reactive substances level was elevated. Our data showed a consistent profile of gastrointestinal injury elicited by sulfur-containing amino acid-homocysteine. This could contribute to explain, at least in part, the mechanisms involved in human gastrointestinal diseases associated to hyperhomocysteinemia.

Methyl-deficient diet promotes colitis and SIRT1-mediated endoplasmic reticulum stress

BACKGROUND

Methyl donor deficiency (MDD) aggravates experimental colitis in rats and increases endoplasmic reticulum (ER) stress through decreased sirtuin 1 (SIRT1) in neuronal cells and myocardium. ER stress plays a key role in IBD pathogenesis.

AIM

We investigated whether the influence of MDD on colitis resulted from an ER stress response triggered by decreased SIRT1 expression.

DESIGN

The unfolded protein response (UPR), chaperones proteins, heat shock factor protein 1 (HSF1) and SIRT1 were examined in rats with MDD and dextran sulfate sodium (DSS)-induced colitis in a Caco-2 cell model with stable expression of transcobalamin-oleosin (TO) chimera, which impairs cellular availability of vitamin B12, and in IBD. The effects of SIRT1 activation were studied both in vitro and in vivo.

RESULTS

MDD aggravated DSS-induced colitis clinically, endoscopically and histologically. MDD activated ER stress pathways, with increased phosphorylate-PKR-like ER kinase, P-eiF-2α, P-IRE-1α, activating transcription factor (ATF)6, XBP1-S protein and ATF4 mRNA expression levels in rats. This was accompanied by reduced SIRT1 expression level and greater acetylation of HSF1, in relation with a dramatic decrease of chaperones (binding immunoglobulin protein (BIP), heat shock protein (HSP)27 and HSP90). Adding either vitamin B12, S-adenosylmethionine or an SIRT1 activator (SRT1720) reduced the UPR in vitro. In rats, SIRT1 activation by SRT1720 prevented colitis by reducing HSF1 acetylation and increasing expression of BIP, HSP27 and HSP90. Immunohistochemistry showed impaired expression of SIRT1 in the colonic epithelium of patients with IBD.

CONCLUSIONS

SIRT1 is a master regulator of ER stress and severity of experimental colitis in case of MDD. It could deserve further interest as a therapeutic target of IBD.

Etiopathogenesis, Prevention, and Treatment of Thromboembolism in Inflammatory Bowel Disease

The close relationship between inflammation and thrombosis affects the progression and severity of inflammatory bowel disease (IBD). The prevalence of venous thromboembolism (VTE) varies between 1% and 7% among patients with IBD. The VTE risk in patients with IBD is at least 3 times higher than that in the normal general population. The absolute risk is very high during hospitalization, active disease, and surgery. The IBD-related VTE occurs at younger ages and recurs more frequently. The development of thrombosis in IBD is due to the interaction of many hereditary and acquired risk factors. Each patient diagnosed with IBD should be evaluated for a personal and family history of thrombosis and for prothrombotic drug use. Although procoagulant factors are increased during the natural course of inflammation, natural anticoagulants and fibrinolytic activity are decreased. Although IBD is accepted as a prothrombotic condition, there is no treatment that can remove this risk from daily practice. Patient training is required to control important factors, such as long-term immobilization and smoking. Oral contraceptives and hormone replacement therapy should be avoided. Inducing permanent disease remission must be the key approach for the prevention of thrombosis. Low-molecular-weight heparin (LMWH) is the basis of prophylactic treatment, which reduces the thrombosis risk by 50%. Prophylaxis with LMWH should be administered to all patients with IBD hospitalized due to disease attack or surgery. Long-term or even life-long anticoagulation therapy should be planned if there is insufficient disease control, recurrent VTE attacks, positive thrombophilia tests, or thrombosis in vital veins.

Polymorphisms of glutathione S-transferase and methylenetetrahydrofolate reductase genes in Moldavian patients with ulcerative colitis: Genotype-phenotype correlation

Background

Glutathione S-transferases (GSTM1, GSTT1, and GSTP1) and methylenetetrahydrofolate reductase (MTHFR) are important enzymes for protection against oxidative stress. In addition, MTHFR has an essential role in DNA synthesis, repair, and methylation. Their polymorphisms have been implicated in the pathogenesis of ulcerative colitis (UC). The aim of the present study was to investigate the role of selected polymorphisms in these genes in the development of UC in the Moldavian population.

Methods

In a case-control study including 128 UC patients and 136 healthy individuals, GSTM1 and GSTT1 genotypes (polymorphic deletions) were determined using multiplex polymerase chain reaction (PCR). The GSTP1 rs1695 (Ile105Val), MTHFR rs1801133 (C677T), and MTHFR rs1801131 (A1298C) polymorphisms were studied with restriction fragment length polymorphism (RFLP) analysis. Genotype–phenotype correlations were examined using logistic regression analysis.

Results

None of the genotypes, either alone or in combination, showed a strong association with UC. The case-only sub-phenotypic association analysis showed an association of the MTHFR rs1801133 polymorphism with the extent of UC under co-dominant (p corrected = 0.040) and recessive (p corrected = 0.020; OR = 0.15; CI = 0.04–0.63) genetic models. Also, an association between the MTHFR rs1801131 polymorphism and the severity of UC was reported for the over-dominant model (p corrected = 0.023; coefficient = 0.32; 95% CI = 0.10–0.54).

Conclusion

The GST and MTHFR genotypes do not seem to be a relevant risk factor for UC in our sample. There was, however, evidence that variants in MTHFR may influence the clinical features in UC patients. Additional larger studies investigating the relationship between GST and MTHFR polymorphisms and UC are required.

Diet-Induced Hyperhomocysteinaemia Increases Intestinal Inflammation in an Animal Model of Colitis

BACKGROUND

Hyperhomocysteinaemia [HHcy] is a common phenomenon observed in patients with inflammatory bowel disease [IBD]. Homocysteine is a pro-inflammatory molecule and has been identified as a risk factor for cardiovascular and cerebral diseases. Whether HHcy contributes to the chronic inflammation of the colon in IBD has rarely been explored. The aim of this study was to investigate the effect of HHcy on dextran sulphate sodium [DSS]-induced colitis.

METHODS

Wistar rats were randomly divided into eight groups: [1] Control; [2] HHcy; [3] p38 inhibitor; [4] DSS; [5] HHcy + DSS; [6] HHcy + DSS+p38 inhibitor; [7] HHcy + DSS [21 days]; and [8] HHcy + DSS + folate [21 days]. Colitis was induced by 5% DSS. HHcy was induced by the normal rodent diet containing 1.7% methionine. The mRNA expression of interleukin 17 [IL-17] was detected by qRT-PCR. The protein expressions of IL-17, retinoid-related orphan nuclear receptor-γt [RORγt], p38 MAPK, phosphorylated-p38 MAPK, cytosolic phospolipaseA2 [cPLA2], phosphorylated-cPLA2, and cyclooxygenase 2 [COX2] were detected by immunoblot analysis.

RESULTS

The rats of the HHcy + DSS group had significantly higher myeloperoxidase [MPO] activity, DAI score, and histological score. HHcy significantly increased the plasma concentration, the colonic mRNA, and the protein levels of IL-17. HHcy also activated p38 MAPK and cPLA2, and increased the protein levels of COX2 and RORγt as well as the plasma level of prostaglandin E2 [PGE2]. Folate supplementation down-regulated homocysteine-induced IL-17 and RORγt expressions.

CONCLUSIONS

HHcy aggravated DSS-induced colitis by stimulating IL-17 expression via the p38/cPLA2/COX2/PGE2 signalling pathway. The folate supplementation may represent a novel approach to treating the chronic intestinal inflammation of IBD exacerbated by HHcy.

Vitamin B12 deficiency in inflammatory bowel disease: prevalence, risk factors, evaluation, and management

BACKGROUND

Management of vitamin B(12) (cobalamin, Cbl) deficiency in inflammatory bowel disease (IBD) is often not evidenced-based because of uncertainty on whether it causes enough malabsorption to result in clinical disease. This systematic review examines whether IBD predisposes to Cbl deficiency. We provide an approach to the management of abnormal Cbl values in IBD based on current literature and consensus-based guidelines.

METHODS

An extensive search of the Ovid MEDLINE and EMBASE databases by independent reviewers identified 42 articles with a total of 3732 patients evaluating Cbl deficiency in IBD.

RESULTS

Crohn's disease without ileal resection, regardless of disease location in the ileum, did not increase the risk for Cbl deficiency. Ileal resections greater than 30 cm were associated with Cbl deficiency in Crohn's disease, whereas those less than 20 cm were not. The effects of 20 to 30 cm resections were inconsistent. Ulcerative colitis did not predispose to deficiency. All studies failed to use confirmatory biomarker testing as stipulated by diagnostic guidelines for Cbl deficiency.

CONCLUSIONS

This literature does not support an association of Crohn's disease in general, regardless of ileal involvement, with Cbl deficiency. Only ileal resections greater than 20 cm in Crohn's disease predispose to deficiency and warrant treatment. Based on these findings, we suggest a diagnostic and therapeutic algorithm. All findings and recommendations require verification in further studies using confirmatory biomarkers as per diagnostic guidelines for Cbl deficiency. Serum Cbl levels alone are likely insufficient to diagnose deficiency in asymptomatic patients.

Decoding norovirus infection in Crohn's disease

Although a causing viral infectious agent remains untraceable in Crohn's disease, most recent genome-wide association studies have linked the FUT2 W143X mutation (resulting in asymptomatic norovirus infection) with the pathogenesis of Crohn's ileitis and with vitamin B12 deficiency (i.e., a known risk factor for Crohn's disease with ileal involvement). In line with these findings, host variations in additional genes involved in host response to norovirus infection (such as ATG16L1 and NOD2) predispose humans to Crohn's ileitis. One may therefore presume that asymptomatic norovirus infection may contribute to disruption of the stability of the gut microbiota leading to Crohn's ileitis. These paradigms highlight not only the need to revisit the potential transmissibility of Crohn's disease, but also potential safety issues of forthcoming clinical trials on human probiotic infusions in Crohn's ileitis by rigorous donors screening program.

Homocysteine, cysteine, and risk of incident colorectal cancer in the Women's Health Initiative observational cohort

BACKGROUND

Inflammation underlies the etiology of colorectal cancer (CRC). Hyperhomocysteinemia is associated with inflammation and may be a risk marker for CRC. Cysteine is a metabolic product of homocysteine and a precursor of the antioxidant glutathione. It is unknown whether cysteine is associated with CRC.

OBJECTIVE

The objective was to assess the associations between homocysteine and cysteine and CRC incidence in postmenopausal women.

DESIGN

Associations between homocysteine and cysteine and incident CRC in the Women's Health Initiative observational cohort were assessed by using a nested case-control design. Cases and controls (n = 988/group) were matched for age (mean ± SD age: 67 ± 7 y), ethnicity (85.2% white, 8.9% black, 2.2% Hispanic/Latina, and 3.6% other), hysterectomy status, and date of blood draw. Homocysteine and cysteine were measured by HPLC with postcolumn fluorimetric detection.

RESULTS

Multivariate-adjusted ORs (95% CIs) for CRC were 1.46 (1.05, 2.04) for the highest quartile of homocysteine (>9.85 μmol/L) compared with the lowest quartile (≤6.74 μmol/L) (P = 0.02) and 0.57 (0.40, 0.82) for the highest quartile of cysteine (>309 μmol/L) compared with the lowest quartile (≤260 μmol/L) (P = 0.01). The association with homocysteine was significant for proximal colon tumors (P = 0.008) but not for distal or rectal tumors, whereas the association with cysteine was significant for rectal tumors (P = 0.02), borderline for proximal tumors (P = 0.06), and not significant for distal tumors. The associations with both homocysteine and cysteine were significant for localized tumors (P ≤ 0.01) but not for metastases.

CONCLUSION

High plasma homocysteine is associated with increased risk of CRC, whereas high cysteine is associated with decreased risk. This trial was registered at clinicaltrials.gov as NCT 00000611.

Dietary beliefs and behavior among inflammatory bowel disease patients

BACKGROUND

We investigated dietary beliefs and behavior in a large population of adult inflammatory bowel disease (IBD) patients and evaluated their impact on patients' social life.

METHODS

A questionnaire of 14 items was administered to all consecutive IBD patients followed at the Nancy University Hospital Department of Gastroenterology from February to July 2011.

RESULTS

A total of 244 patients participated in the survey; 15.6% (n = 38) of patients believed that diet could initiate the disease, while 57.8% (n = 141) believed that food can play a role in causing a relapse. Forty percent (107/244) of patients identified food as a risk factor for relapse. Seventy-three percent of respondents reported having already received nutritional advice. The majority of respondents (47.5%, n = 116) reported that the disease had changed the pleasure of eating. Only one-quarter of patients had a normal diet in case of relapse. Almost two out of three patients (66.8%, n = 163) reported not eating certain foods they usually like to eat in order to prevent a relapse. Dietary beliefs and behavior had an impact on their social life for one-fifth of patients. Excluding food was associated with refusing outdoor dining for fear of causing relapse (P = 0.006) and not sharing the same menu as the other members of the family living under the same roof (P = 0.002).

CONCLUSIONS

The majority of IBD patients are avoiding certain foods. Dietary beliefs and behavior have a strong impact on their social life.

Methyl donor deficiency affects small-intestinal differentiation and barrier function in rats

Dietary methyl donors and their genetic determinants are associated with Crohn's disease risk. We investigated whether a methyl-deficient diet (MDD) may affect development and functions of the small intestine in rat pups from dams subjected to the MDD during gestation and lactation. At 1 month before pregnancy, adult females were fed with either a standard food or a diet without vitamin B12, folate and choline. A global wall hypotrophy was observed in the distal small bowel (MDD animals 0·30 mm v. controls 0·58 mm; P< 0·001) with increased crypt apoptosis (3·37 v. 0·4 %; P< 0·001), loss of enterocyte differentiation in the villus and a reduction in intestinal alkaline phosphatase production. Cleaved caspase-3 immunostaining (MDD animals 3·37 % v. controls 0·4 %, P< 0·001) and the Apostain labelling index showed increased crypt apoptosis (3·5 v. 1·4 %; P= 0·018). Decreased proliferation was observed in crypts of the proximal small bowel with a reduced number of minichromosome maintenance 6 (MDD animals 52·83 % v. controls 83·17 %; P= 0·048) and proliferating cell nuclear antigen-positive cells (46·25 v. 59 %; P= 0·05). This lack of enterocyte differentiation in the distal small bowel was associated with an impaired expression of β-catenin and a decreased β-catenin–E-cadherin interaction. The MDD affected the intestinal barrier in the proximal small bowel by decreasing Paneth cell number after immunostaining for lysosyme (MDD animals 8·66 % v. controls 21·66 %) and by reducing goblet cell number and mucus production after immunostaining for mucin-2 (crypts 8·66 v. 15·33 %; villus 7 v. 17 %). The MDD has dual effects on the small intestine by producing dramatic effects on enterocyte differentiation and barrier function in rats.

Dietary folate does not significantly affect the intestinal microbiome, inflammation or tumorigenesis in azoxymethane-dextran sodium sulphate-treated mice

Inflammatory bowel disease (IBD) is a risk factor for the development of colon cancer. Environmental factors including diet and the microflora influence disease outcome. Folate and homocysteine have been associated with IBD-mediated colon cancer but their roles remain unclear. We used a model of chemically induced ulcerative colitis (dextran sodium sulphate (DSS)) with or without the colon carcinogen azoxymethane (AOM) to determine the impact of dietary folic acid (FA) on colonic microflora and the development of colon tumours. Male mice (n 15 per group) were fed a FA-deficient (0 mg/kg), control (2 mg/kg) or FA-supplemented (8 mg/kg) diet for 12 weeks. Folate status was dependent on the diet (P< 0·001) and colitis-induced treatment (P= 0·04) such that mice with colitis had lower circulating folate. FA had a minimal effect on tumour initiation, growth and progression, although FA-containing diets tended to be associated with a higher tumour prevalence in DSS-treated mice (7-20 v. 0%, P= 0·08) and the development of more tumours in the distal colon of AOM-treated mice (13-83% increase, P= 0·09). Folate deficiency was associated with hyperhomocysteinaemia (P< 0·001) but homocysteine negatively correlated with tumour number (r - 0·58, P= 0·02) and load (r - 0·57, P= 0·02). FA had no effect on the intestinal microflora. The present data indicate that FA intake has no or little effect on IBD or IBD-mediated colon cancer in this model and that hyperhomocysteinaemia is a biomarker of dietary status and malabsorption rather than a cause of IBD-mediated colon cancer.

Methyl deficient diet aggravates experimental colitis in rats

Inflammatory bowel diseases (IBD) result from complex interactions between environmental and genetic factors. Low blood levels of vitamin B12 and folate and genetic variants of related target enzymes are associated with IBD risk, in population studies. To investigate the underlying mechanisms, we evaluated the effects of a methyl-deficient diet (MDD, folate, vitamin B12 and choline) in an experimental model of colitis induced by dextran sodium sulphate (DSS), in rat pups from dams subjected to the MDD during gestation and lactation. Four groups were considered (n= 12–16 per group): C DSS⁻ (control/DSS⁻), D DSS⁻ (deficient/DSS⁻), C DSS⁺ (control/DSS⁺) and D DSS⁺ (deficient/DSS⁺). Changes in apoptosis, oxidant stress and pro-inflammatory pathways were studied within colonic mucosa. In rat pups, the MDD produced a decreased plasma concentration of vitamin B12 and folate and an increased homocysteine (7.8 ± 0.9 versus 22.6 ± 1.2 μmol/l, P < 0.001). The DSS-induced colitis was dramatically more severe in the D DSS⁺ group compared with each other group, with no change in superoxide dismutase and glutathione peroxidase activity, but decreased expression of caspase-3 and Bax, and increased Bcl-2 levels. The mRNA levels of tumour necrosis factor (TNF)-α and protein levels of p38, cytosolic phospolipase A2 and cyclooxygenase 2 were significantly increased in the D DSS⁺ pups and were accompanied by a decrease in the protein level of tissue inhibitor of metalloproteinases (TIMP)3, a negative regulator of TNF-α. MDD may cause an overexpression of pro-inflammatory pathways, indicating an aggravating effect of folate and/or vitamin B12 deficiency in experimental IBD. These findings suggest paying attention to vitamin B12 and folate deficits, frequently reported in IBD patients.

Meta-analysis: hyperhomocysteinaemia in inflammatory bowel diseases

BACKGROUND

The magnitude of association between homocysteine metabolism and inflammatory bowel diseases (IBD) remains unknown, whereas the association between hyperhomocysteinaemia and thrombosis remains controversial in IBD.

AIM

To conduct a systematic review and meta-analysis to examine these issues.

METHODS

The literature search was conducted using MEDLINE database and international conference abstracts from January 1966 to April 2011 and included all studies that evaluated plasma homocysteine level in IBD.

RESULTS

Twenty-eight studies evaluated the plasma homocysteine level and/or hyperhomocysteinaemia risk in IBD patients. Five studies assessed the association of hyperhomocysteinaemia with thrombosis. The mean plasma homocysteine level was significantly higher in IBD patients when compared with controls (weighted mean difference (WMD)=3.75 μmol/L; 95% CI, 2.23-5.26 μmol/L; P<0.0001; reference ranges for plasma homocysteine level: 5-12 μmol/L). The mean plasma homocysteine level did not differ between ulcerative colitis (UC) and Crohn's disease (CD) (WMD=0.41 μmol/L; 95% CI, -2.45 to 3.06 μmol/L; P=0.76). The risk of hyperhomocysteinaemia was significantly higher in IBD patients when compared with controls [odds ratio (OR)=4.65; 95% CI, 3.04-7.09; P<0.0001]. The risk of hyperhomocysteinaemia was not higher among IBD patients who experienced thromboembolic complications (OR=1.97; 95% CI, 0.83-4.67; P=0.12). Plasma folate level was inversely correlated with IBD risk associated with MTHFR C677T polymorphism (P=0.006).

CONCLUSIONS

The risk of hyperhomocysteinaemia is significantly higher in IBD patients when compared with controls. The risk assessment of hyperhomocysteinaemia-related thrombosis in IBD requires further investigation. Deficient folate status is associated with a higher impact of MTHFR C677T polymorphism on IBD risk.

Prevalence and risk factors of hyperhomocysteinemia in Tunisian patients with Crohn's disease

BACKGROUND AND AIMS

The role of hyperhomocysteinemia (HHC) and its determinants in Crohn's disease (CD) remain uncertain. This study was aimed to determine the prevalence of HHC and its main risk factors in Tunisian patients with CD.

METHODS

This study included 89 patients with CD and 103 age- and sex-matched healthy subjects. Fasting venous blood was collected in all subjects allowing the assessment of homocysteine, folate, vitamin B(12), C-reactive protein and creatinine levels. Logistic regression models were applied to identify factors associated with HHC in CD patients.

RESULTS

Plasma homocysteine was higher (13.69 ± 4.84μmol/l vs. 10.77 ± 2.80μmol/l; p<0.01) and HHC was more frequent (31.5% vs. 7.8%; p<0.001) in patients compared with controls. The association between HHC and CD persisted after adjustment for smoking, body mass index and serum folate, vitamin B(12), creatinine and C-reactive protein. In patients with CD, multivariate analysis showed that HHC was positively associated with age [multi-adjusted odds-ratio (95% confidence interval): 1.14 (1.06-1.24); p<0.001], active disease [7.54 (1.15-49.3); p=0.03], disease duration >2 years [8.69 (1.53-49.3); p=0.02] and inversely related to plasma folate [0.64 (0.48-0.84); p=0.002] and vitamin B(12) (0.993 (0.987-0.999); p=0.02].

CONCLUSION

HHC is common in Tunisian patients with CD and is related to B vitamins deficit, as well as disease activity and duration. Further studies should test the effect of correction of HHC by vitamin B supplementation on progression and complications of CD.

Thrombosis and inflammatory bowel disease: a call for improved awareness and prevention

Thrombotic complications in patients with inflammatory bowel disease (IBD) are common and require improved awareness and prevention. In this review the interface between IBD and thrombosis is discussed, with emphasis on risk assessment and data to aid clinical decision making. Thromboembolic complications are 3-fold more likely in IBD patients than controls and the relative risk exceeds 15 during disease flares. Improved assessment of thrombosis risk for an individual patient includes thorough personal and family history and awareness of prothrombotic medications and lifestyle choices. Patients with the highest risk of thrombosis are those with active colonic disease, personal or strong family history of thrombosis, and those with significant acquired risk factors. Combined risk factors or hospitalization should prompt mechanical thromboprophylaxis. Indications for prophylactic anticoagulation are not defined currently by clinical studies, especially in pediatric patients, although some groups now advocate prophylactic anticoagulation for all hospitalized IBD patients and even some outpatients with disease flares. Thrombosis management requires a multidisciplinary therapeutic approach to balance anticoagulation and bleeding risk. While bleeding may occur with anticoagulation in IBD, data and experience indicate that therapeutic heparin is safe and bleeding manifestations can be managed supportively in most patients. Until prospective trials of prophylactic anticoagulation are published, management of thrombotic risk and prophylaxis in IBD will remain a clinical challenge.

MTHFR, MTR, and MTRR polymorphisms in relation to p16INK4A hypermethylation in mucosa of patients with colorectal cancer

We recently analyzed the hypermethylation status of the p16INK4a (p16) gene promoter in normal-appearing mucosa obtained from patients with colorectal cancer. Hypermethylation of p16 was associated with reduced survival of these patients. In the present study, germ line polymorphisms in the folate- and methyl-associated genes, methylenetetrahydrofolate reductase (MTHFR), methionine synthase (MTR) and methionine synthase reductase (MTRR), were analyzed in the same patient cohort to find a possible link between these genetic variants and p16 hypermethylation. Genomic DNA was extracted from blood of patients (n = 181) and controls (n = 300). Genotype analyses were run on an ABI PRISM(®) 7900HT sequence-detection system (Applied Biosystems), using real-time polymerase chain reaction and TaqMan chemistry. The results showed that the genotype distributions of the patient and control groups were similar. No significant differences in cancer-specific or disease-free survival of stage I-III patients according to polymorphic variants were detected, nor were any differences in cancer-specific or disease-free survival detected when patients were subgrouped according to the MTHFR or MTR genotype groups and dichotomized by p16 hypermethylation status in mucosa. However, patients with the MTRR 66 AA/AG genotypes were found to have a significantly worse cancer-specific survival when the mucosa were positive, compared with negative, for p16 hypermethylation (hazard ratio 2.7; 95% confidence interval 1.2-6.4; P = 0.023). In contrast, there was no difference in survival among patients with the MTRR 66 GG genotype stratified by p16 hypermethylation status. These results indicate a relationship between genetic germ-line variants of the MTRR gene and p16 hypermethylation in mucosa, which may affect the clinical outcome of patients with colorectal cancer.

MTHFR, MTR, and MTRR polymorphisms in relation to p16INK4A hypermethylation in mucosa of patients with colorectal cancer

We recently analyzed the hypermethylation status of the p16INK4a (p16) gene promoter in normal-appearing mucosa obtained from patients with colorectal cancer. Hypermethylation of p16 was associated with reduced survival of these patients. In the present study, germ line polymorphisms in the folate- and methyl-associated genes, methylenetetrahydrofolate reductase (MTHFR), methionine synthase (MTR) and methionine synthase reductase (MTRR), were analyzed in the same patient cohort to find a possible link between these genetic variants and p16 hypermethylation. Genomic DNA was extracted from blood of patients (n = 181) and controls (n = 300). Genotype analyses were run on an ABI PRISM(®) 7900HT sequence-detection system (Applied Biosystems), using real-time polymerase chain reaction and TaqMan chemistry. The results showed that the genotype distributions of the patient and control groups were similar. No significant differences in cancer-specific or disease-free survival of stage I-III patients according to polymorphic variants were detected, nor were any differences in cancer-specific or disease-free survival detected when patients were subgrouped according to the MTHFR or MTR genotype groups and dichotomized by p16 hypermethylation status in mucosa. However, patients with the MTRR 66 AA/AG genotypes were found to have a significantly worse cancer-specific survival when the mucosa were positive, compared with negative, for p16 hypermethylation (hazard ratio 2.7; 95% confidence interval 1.2-6.4; P = 0.023). In contrast, there was no difference in survival among patients with the MTRR 66 GG genotype stratified by p16 hypermethylation status. These results indicate a relationship between genetic germ-line variants of the MTRR gene and p16 hypermethylation in mucosa, which may affect the clinical outcome of patients with colorectal cancer.

Multivitamin use and telomere length in women

BACKGROUND

Telomere length may be a marker of biological aging. Multivitamin supplements represent a major source of micronutrients, which may affect telomere length by modulating oxidative stress and chronic inflammation.

OBJECTIVE

The objective was to examine whether multivitamin use is associated with longer telomeres in women.

DESIGN

We performed a cross-sectional analysis of data from 586 early participants (age 35-74 y) in the Sister Study. Multivitamin use and nutrient intakes were assessed with a 146-item food-frequency questionnaire, and relative telomere length of leukocyte DNA was measured by quantitative polymerase chain reaction.

RESULTS

After age and other potential confounders were adjusted for, multivitamin use was associated with longer telomeres. Compared with nonusers, the relative telomere length of leukocyte DNA was on average 5.1% longer among daily multivitamin users (P for trend = 0.002). In the analysis of micronutrients, higher intakes of vitamins C and E from foods were each associated with longer telomeres, even after adjustment for multivitamin use. Furthermore, intakes of both nutrients were associated with telomere length among women who did not take multivitamins.

CONCLUSION

This study provides the first epidemiologic evidence that multivitamin use is associated with longer telomere length among women.

Folate status in various pathophysiological conditions

Folate is the generic term for compounds that have vitamin activity similar to that of pteroylglutamic acid. Folate acts as a coenzyme in several single carbon transfers involved in biosynthesis of purine nucleotides and deoxythymidylic acid essential for DNA and RNA synthesis. In addition, folate provides one-carbon unit for methylation of a wide variety of biological substances including DNA, proteins, phospholipids, and neurotransmitters, thereby regulating their function. Recent epidemiological-clinical and experimental studies suggest the association of folate deficiency with the risk of various cancers, birth defects, and cardiovascular diseases. Thus, it is important to consider the conditions that are associated with altered folate status and their consequences. The impairment in folate status has been found in number of pathophysiological conditions like inflammatory bowel disease, cancer, alcoholism, pregnancy, neonatal growth, and during administration of some drugs. The recent advances dealing with mechanistic aspects of impaired folate status in these conditions have been discussed in this review.

Evidence of endothelial dysfunction in patients with inflammatory bowel disease

BACKGROUND & AIMS

Chronic inflammation has a major role in the development and propagation of endothelial dysfunction, which can lead to coronary artery disease. Endothelial dysfunction has been described in patients with various and diverse chronic inflammatory conditions. Altered vascular flow has been proposed to mediate inflammation in inflammatory bowel disease (IBD), although the role of endothelial dysfunction remains obscure. The purpose of our study was to assess endothelial function in patients with IBD.

METHODS

Ninety-eight subjects were included in this study; 48 with IBD (17 with ulcerative colitis and 31 with Crohn's disease) and 50 healthy controls. Endothelial function was assessed by pulse arterial tonometry (PAT) and brachial ultrasound to determine flow-mediated dilation and shear stress reactive hyperemia. The impact of disease activity, disease duration, and IBD therapy also was assessed.

RESULTS

Baseline demographic characteristics, including cardiovascular risk factors, were similar in all groups. IBD patients showed microvascular endothelial dysfunction, with lower PAT indices (P < .01) and shear stress reactive hyperemia (P < .05) compared with controls. There was no relationship between microvascular endothelial dysfunction, disease duration, underlying therapy, or clinical disease activity. There was a positive association between lower PAT scores and recent abdominal pain (P < .05).

CONCLUSIONS

This was a large study assessing endothelial dysfunction in IBD. Both ulcerative colitis and Crohn's disease patients showed evidence of microvascular endothelial dysfunction. Future research could determine whether endothelial dysfunction is involved in the pathogenesis of IBD or increases the risk of cardiovascular events in this patient population.

Methionine synthase A2756G polymorphism may predict ulcerative colitis and methylenetetrahydrofolate reductase C677T pancolitis, in Central China

Background

The association of genetic polymorphisms related to metabolism of homocysteine with inflammatory bowel disease has been evidenced in Crohn disease and remains an open question in ulcerative colitis. We evaluated the association of the polymorphisms of MTHFR, MTR, MTRR and TCN2 genes with ulcerative colitis in Central China.

Methods

168 patients were genotyped for these polymorphisms and compared to 219 matched controls.

Results

Methionine synthase 2756G allele frequency was higher in ulcerative colitis than in controls 0.15 (95% C.I. 0.11–0.19) vs 0.09 (95% C.I. 0.07 – 0.12), (P = 0.0137) and predicted ulcerative colitis risk in logistic regression, with an Odds ratio at 1.8 (95% C.I. 1.15–2.84). Methylenetetrahydrofolate reductase 677TT genotype was 2.7-fold more prevalent in individuals with pancolitis than in those with left colitis or proctitis, with respective percentages of 27.3 (95% C.I.16.4–42.0) and 10.5 (95% C.I. 6.3–17.1) (P = 0.0123). The carriage of 677TT or 677CT/1298AC genotypes of methylenetetrahydrofolate reductase was more frequent in cases with pancolitis than in subjects with left colitis or proctitis (P = 0.0048), with an Odds ratio adjusted by age and sex at 3.3 (95% C.I. 1.4–7.9), P = 0.0084) in logistic regression.

Conclusion

Methionine synthase and methylenetetrahydrofolate reductase are genes of vitamin B12 and folate cellular metabolism associated respectively with risk and extent of ulcerative colitis, at least in Central China. This finding may open new insights, particularly for the potential interest in treating patients carrying the 677TT MTHFR genetic trait and a deficit in folate.

Association of MTRR 66A>G polymorphism with superoxide dismutase and disease activity in patients with Crohn's disease

OBJECTIVES

The aim of this study was to evaluate the association of nutritional (folate, vitamin B12) and genetic (MTHFR, MTR, MTRR, TCN) determinants of homocysteine metabolism and of superoxide dismutase with Crohn's disease (CD).

METHODS

One hundred forty patients with CD were compared with 248 matched healthy controls.

RESULTS

Plasma homocysteine levels were higher in CD patients than controls (11.8 vs 10.4 micromol/L, P= 0.0004). Vitamin B12 and folate levels were lower in CD subjects compared to controls (207 vs 255 pmol/L, P= 0.0082, and 8.6 vs 11 nmol/L, P= 0036, respectively). Patients with a personal history of ileal resection, ileitis, or colectomy had significantly lower vitamin B12 levels. In multivariate analysis, vitamin B12 and MTHFR 677 TT carriers were the two significant independent factors of plasma homocysteine >15 micromol/L in CD patients (P= 0.0187 and 0.0048, respectively). The significant association between homocysteine and vitamin B12 levels remained significant only in patients with the highest superoxide dismutase values (P < 0.0001). The MTRR AA genotype was a significant independent predictor of CD risk (odds ratio 3.7, 95% CI 1.218-11.649, P= 0.0213). The level of superoxide dismutase was significantly higher (P= 0.0143) and was correlated with Crohn's Disease Activity Index (CDAI) scores (P for trend = 0.0276) in patients carrying MTRR AA genotype.

CONCLUSIONS

Vitamin B12 and MTHFR 677 TT genotype are the main determinants of hyperhomocysteinemia in CD patients. The association of MTRR 66A>G polymorphism with oxidant stress and disease activity provides rationale for screening vitamin deficiencies in these patients.