Hyperhomocysteinemia is associated with venous thrombosis in patients with short bowel syndrome

Impact of a multidisciplinary nutritional support team on quality improvement for patients receiving home parenteral nutrition

Introduction

Home parenteral nutrition (HPN) is essential for patients with intestinal failure requiring long-term nutritional support. The Amerita Quality Improvement Project for HPN Patients (QIP-PN) explored the effect of a physician nutrition expert (PNE)-led multidisciplinary nutritional support team (MNST) on HPN care for patients under its service.

Objective

To determine an MNST effect on adherence to protocols, outcomes and quality of life (QOL) in HPN.

Methods

The study was divided into three phases: data review (phases 1a and 1b), observation (phase 2) and intervention (phase 3). Seven Amerita locations were selected as 'study branches' (population), from which all study patients and controls were drawn. The quality improvement project employed a quasi-experimental case-matched control group (control) design. Data were collected on demographics, treating physicians PNE status, HPN care variables, recommended interventions, quality-of-life assessment, adverse outcomes and hospitalisations. Paired t-test compared continuous data between phases 2 and 3. Comparisons between study and control groups used a negative binomial regression model.

Results

Thirty-four patients were reviewed in phase 1a and 197 in phase 1b. Forty study patients completed phase 2 and progressed into phase 3, of whom 30 completed ≥60 therapy days. Patients were lost to follow-up if they discontinued HPN for any reason. Improvements in weight, body mass index and QOL were seen in the study patients during intervention. Recommendations made and accepted by treating physicians differed based on PNE status. Study patients had fewer adverse outcomes and related hospitalisations than controls.

Conclusion

MNST recommendations improved clinical, biochemical parameters and patients' self-reported overall health. MNST input reduced adverse outcomes, hospitalisation and the length of stay at the hospital. This study highlights the potential for MNST to have a significant impact on the quality and overall cost of HPN management.

Choline Deficiency Is Associated With Increased Risk for Venous Catheter Thrombosis

BACKGROUND

Patients with intestinal failure who require long-term parenteral nutrition (PN) develop catheter thrombosis as a complication. This patient group may also develop choline deficiency because of a defect in the hepatic transsulfuration pathway in the setting of malabsorption. This study was undertaken to determine whether choline deficiency is a risk factor for development of catheter thrombosis.

METHODS

Plasma free and phospholipid-bound choline concentrations were measured in a group of 41 patients that required long-term PN. Episodes of catheter thrombosis from onset of PN to the time of blood testing were recorded.

RESULTS

Sixteen (39%) patients developed catheter thrombosis, and 5 of these had recurrent catheter thrombosis. Plasma free choline was 7.7 +/- 2.7 nmol/mL in patients with no history of catheter thrombosis and 6.2 +/- 1.7 nmol/mL in patients with previous catheter thrombosis (p = .076 by Wilcoxon rank-sum test). The partial correlation between plasma free choline concentration and the frequency of clots after controlling for catheter duration was r = -0.33 (p = .038). The relative risk for catheter thrombosis in subjects with a plasma free choline concentration <8 nmol/mL was 10.0, 95% confidence interval (1.134-88.167). Plasma phospholipid-bound choline concentration was 2191.7 +/- 679.0 nmol/mL in patients with previous catheter thrombosis and 2103.3 +/- 531.2 nmol/mL in patients without history of catheter thrombosis (p = NS).

CONCLUSION

Choline deficiency is a significant risk factor for development of catheter thrombosis in patients with intestinal failure who require PN.

Association between B-group vitamins and venous thrombosis: systematic review and meta-analysis of epidemiological studies

A homocysteine-independent role for B-group vitamins on venous thrombosis (VT) development has been reported. However, related research findings remain inconsistent. PUBMED, EMBASE, and COCHRANE databases were searched to collect information on all eligible studies to make a meta-analysis about the relationship between B-group vitamins and VT. Literature search results did not suggest a correlation between thiamin, pantothenic acid, niacin, or riboflavin with VT. Based on their correlations in the literature, folic acid, vitamin B12, B6 were considered in the meta-analysis and systematic review. Significant standardized mean differences were obtained for plasma folic acid (-0.55; 95% CI, -0.75 to -0.36) and vitamin B12 (-0.34; 95% CI, -0.55 to -0.13). Reduced levels of folic acid and vitamin B12 may be independent risk factors of VT. Moreover, a qualitative systematic review indicated that low level of vitamin B6 was an independent risk factor of VT. Randomized clinical studies of B-group vitamins supplementation showed varying results on VT prevention. Multivitamin supplementation for VT prevention, regardless of homocysteine level, would be of interest. Further prospective clinical studies are needed to provide additional evidence on the clinical benefits of B-group vitamin supplementation for VT.

Venous thrombosis associated with pernicious anaemia. A report of two cases and review

Since homocystinuria, an inborn metabolism error is complicated by venous thrombosis in about half of the patients, hyperhomocysteinemia has been suspected of favouring thrombosis. Several case-control studies and even meta-analysis have confirmed a link between venous thrombosis and mild hyperhomocysteinemia. Nevertheless, the proper role of homocysteine remains debated. Hyperhomocysteinemia is induced by vitamin B9 or B12 deficiencies in a vast majority of cases. The authors report on two patients with venous thrombosis revealing pernicious anemia and review nine similar cases found in the world literature. The literature concerning the relationships between homocysteine and venous thrombosis is briefly reviewed.

Low levels of vitamin B12 and venous thromboembolic disease in elderly men

OBJECTIVES

Hyperhomocysteinaemia is a well-known risk factor for venous thromboembolic disease (VTD). However, it is not clear whether homocysteine (Hc) itself or a related metabolite or a cofactor is primarily responsible for VTD. We carried out a case-control study to investigate whether vitamin concentrations that are involved in the Hc metabolism are associated or not with an elevated risk of VTD.

DESIGN

Case-control study.

METHODS

We measured serum vitamin B12, folate, creatinine and albumin concentrations and plasma Hc concentrations in 101 consecutive patients with VTD, diagnosed by image tests and 101 control subjects, matched for age and sex.

RESULTS

Serum vitamin B12 concentrations were significantly lower in VTD patients than in the control subjects. There were no differences in plasma Hc or serum folate concentrations between the groups. Among the male subgroup aged more than 70 years, serum vitamin B12 concentrations were significantly lower (240.88 +/- 103.07 vs. 421.20 +/- 314.31 pmol L(-1); P = 0.03) and plasma Hc concentrations were significantly higher (13.1 +/- 4.18 vs. 10.56 +/- 3.06 micromol L(-1); P =0.04) in VTD patients than in the control group. On multivariate analysis, in patients aged more than 70 years, serum vitamin B12 concentrations were independently associated with VTD. Compared with the highest quartile of vitamin B12 (>512.6 pmol L(-1)) the odds ratio (OR) for VTD in the lowest quartile (<230.9 pmol L(-1)) was 3.8 (95% CI 1.44-10.18; P = 0.01). In the VTD group, lowest vitamin B12 concentrations (percentile 10 <152.8 pmol L(-1)) were associated with the factor V Leiden mutation (OR = 6.07, 95% CI 0.93-38.55; P = 0.04).

CONCLUSIONS

Measuring vitamin B12 concentrations in elderly males may help in identifying people at risk of venous thromboembolism in our population.

Fish or chips?

Cell membranes are not simply barriers separating intracellular from extracellular space. Rather, they represent a dynamic high-turnover system that adapts to current demands. During inflammation, prostaglandins and leukotrienes are formed from membrane-derived phospholipids. Encouraging improvements in critically ill patients were observed after nutritional replacement of long-chain omega-6 fatty acids with long-chain omega-3-fatty acids, contained in fish oil.

The Risk of Venous Thromboembolism Associated with the Factor V Leiden Mutation and Low B-Vitamin Status

Venous thromboembolism (VTE) is a multi-factorial disease involving numerous genetic and environmental risk factors. In this study we investigated the occurrence and the risk associated with factor V Leiden, hyperhomocysteinemia and low folate and vitamin B12 levels in young patients with thrombosis. We studied 78 patients (33 females/45 males, mean age 33 years) with a history of thrombosis in a lower limb. Additionally, 98 healthy subjects (45 females/54 males, mean age 44 years) were included. Serum levels of homocysteine (Hcy), folate and vitamin B12 were assayed. Factor V Leiden and methylenetetrahydrofolate reductase (MTHFR) C677T mutations were investigated in all subjects. Factor V Leiden was highly prevalent in the patients (39% heterozygous, 10% homozygous vs. 6.3% heterozygous in controls). An increase in the risk of idiopathic VTE was associated with Hcy levels > 15.2 micromol/l (odds ratio, OR = 2.83), folate < 15.1 nmol/l (OR = 7.49) and vitamin B12 < 182 pmol/l (OR = 11.97). Low levels of folate or vitamin B12 were independently and strongly associated with the risk of VTE in a multivariate model (OR for idiopathic thrombosis = 16.44 and 10.76, respectively). Twenty patients (53%), carriers of factor V Leiden, had low levels of vitamin B12, compared to 28% of patients who were non-carriers of the mutation (p = 0.03). In contrast, none of the control carriers of the mutation had a low level of vitamin B12. The risk of VTE associated with lower levels of vitamin B12 and folate was stronger than that introduced by elevated Hcy levels. The increased risk of VTE, accompanied by factor V Leiden, may be related to confounding environmental factors.