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Dietary nitrate – An unrecognized nutrient?
Abstracts / Clinical Nutrition ESPEN 10 (2015) e174ee212
e201
There was no correlation between lifestyle factors and number of CRBSI, r¼0.01, P¼0.4. In the year prior to reassessment the number of CRBSI per patient was 1-3, mean 1.6, mode 1. In the year after it was 0-2, mean 0.5, mode 0. This was not statistically significant P¼0.1. While the reduction in CRBSI episodes following tailored advice was not statistically significant, detailed reassessment identified many areas of non adherence suggesting periodic re-evaluation is of use.
3. Allen JD, Giordano T, Kevil CG. Nitrite and nitric oxide metabolism in peripheral artery disease. Nitric Oxide. 2012;26: 217-222. 4. Presley TD, Morgan AR, Bechtold E, et al. Acute effect of a high nitrate diet on brain perfusion in older adults. Nitric Oxide. 2011;24:34-42. 5. Schiffer T, Weitzberg E, Lundberg JO, & Larsen FJ. Dietary inorganic nitrate reduces basal metabolic rate in man. Nitric Oxide. 2013;31: 546.
OC55. DIETARY NITRATE e AN UNRECOGNIZED NUTRIENT?
OC56. OUTCOME OF THE FIRST TWENTY PATIENTS IN A HOME PARENTERAL NUTRITION (HPN) SERVICE AT GUYS AND ST. THOMAS' HOSPITAL
A. Ashworth, S.J. Bailey, G.M. Hayward, F. DiMenna, A. Vanhatalo, A.M. Jones. Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Heavitree Road, Exeter, EX1 2 LU, UK Nitric oxide (NO), a powerful signalling molecule, regulates vascular flow, blood pressure, and tissue responses to hypoxia. Previous research suggested that NO is derived from endogenous synthesis via the conversion of L-arginine to L-citrulline, which is oxygen dependent. Recent research has demonstrated the important role of exogenous synthesis, via consumption of dietary nitrate (NO3), which may subsequently be converted to nitrite (NO2) and NO in hypoxic conditions1. Dietary nitrate supplements reduce blood pressure2, improve exercise tolerance in peripheral arterial disease3, improve cerebral perfusion in older adults4 and reduce oxidative stress markers5. However, nitrate is a strictly controlled, environmental contaminant and not regarded as a nutrient essential for health. Plasma [nitrate] and [nitrite] increase after dietary nitrate supplements such as beetroot juice and sodium nitrate, but few studies have used whole, high nitrate vegetables to supplement a normal diet. The purpose of this study was to identify the effects of supplementation with high and low nitrate vegetables on plasma [nitrate], [nitrite], and blood pressure (BP) in a randomized, crossover trial. Fifteen non-smoking, physically active males, 18-40 years, were recruited from the University of Exeter, from January 2011 to March 2012. Participants received either high or low nitrate vegetables for 2-week periods, with a 2-week ‘wash out’ in between. The results indicated significant main and interaction effects of dietary nitrate intake on plasma [nitrate] (P < 0.05) and plasma [nitrite] (P < 0.05). Post hoc tests revealed that supplementation with high nitrate vegetables significantly increased plasma [nitrate] (baseline: 29.5 ± 20.0 mM; after high nitrate vegetables: 129.4 ± 87.1 mM, P < 0.05) and plasma [nitrite] (baseline: 118.9 ± 35.2 nM; after high nitrate vegetables: 226.5 ± 89.3 nM, P < 0.05). Mean systolic BP, diastolic BP and mean arterial pressure were reduced by 3 mmHg, (statistically non-significant), after consumption of high nitrate vegetables. There was no reduction in BP after eating low nitrate vegetables. There were significant correlations between changes in plasma [nitrate], [nitrite] and BP, indicating that as plasma [nitrate] and [nitrite] increased, systolic BP, diastolic BP and mean arterial pressure were reduced. In conclusion, supplementation with high nitrate vegetables increased plasma [nitrate] and [nitrite], which correlated significantly with changes in BP. These findings challenge existing dogma and support the need for research to establish dietary nitrate as a future nutrient in clinical nutrition, both in therapeutics and prevention of disease.
Correlation between changes in variables > high nitrate vegetables
Statistics*
Significance (P)
Systolic BP and [nitrate] Diastolic BP and [nitrite] Mean arterial blood pressure and [nitrate]
r ¼ e .49 r ¼ e .56 r ¼ e .44
0.03 0.02 0.05
*Pearson’s correlation coefficient, where r ¼ .50 indicates large effect size
1. Lundberg JO, Weitzberg E, Gladwin MT. The nitrate-nitrite-nitric oxide pathway in physiology and therapeutics. Nat Rev Drug Disc. 2008;7:156167. 2. Siervo M, Lara J, Ogbonmwan I, Mathers JC. Inorganic nitrate and beetroot juice supplementation reduces blood pressure in adults: a systematic review and meta-analysis. J Nutr. 2013;143:818-26.
M. McCarthy 1, J.M. Dunn 1, S. O'Sullivan 1, S. Fong 1, H. Al-Hilou 1, J. Le Couteur 2, A. White 2, C. Coker 3, C. Pool 3, A. Williams 4, V. Datta 4. 1Department of Gastroenterology Lambeth Palace Road, London SE1 7EH, UK; 2Nutrition and Dietetics department Lambeth Palace Road, London SE1 7EH, UK; 3Pharmacy department Lambeth Palace Road, London SE1 7EH, UK; 4Department of Colorectal Surgery at Guys and St. Thomas’ NHS Foundation Trust, Lambeth Palace Road, London SE1 7EH, UK A Home Parenteral Nutrition (HPN) service was set up at Guy’s and St. Thomas’ Hospitals in August 2010, to meet the demands of treating Intestinal Failure (IF) in the South East region, particularly secondary to the emergence of a tertiary vascular centre at our trust. We present outcome data for the first 3 years. Data were collected from consecutive patients on HPN from medical records and stored in a prospective database. Twenty patients (12 male) have been treated with HPN. Mean age is 53 years (range 22 to 76 years). Indications for HPN were acute bowel ischaemia n¼6, acute bowel ischaemia and enterocutaneous fistula (ECF) n¼3, ECF alone n¼3 (2 had Crohn’s disease), perforated diverticular disease n¼1, small bowel perforation due to lymphoma n¼1, high output ileostomy n¼4 (3 had underlying malignancy), gastric outlet obstruction with distal jejunal structuring n¼1 and chronic pseudo-obstruction n¼1.The mean HPN duration was 225.9 days (range 7 days to 952 days) Overall survival at time of reporting was 75% (15/20). Of these 15, 47% (7/15) have undergone reconstructive surgery and a further 33% (5/15) are awaiting surgery. The remaining 20% (3/15) are Type 3 IF patients that are jointly followed with St Marks’ IF Unit. Of the 5 patients who have died, 1 had come off HPN successfully but died 9 months later from complications from his multiple myeloma. The remaining 4 patients died on HPN, 3 secondary to malignancy and 1 from catastrophic extension of gut ischaemia secondary to Degos disease. 5/20 (25%) patients had a documented catheter related blood stream infection (CRBSI). There were 7 episodes, (3 had a single infection, 2 had 2 infections). This gave an overall infection rate of 1.5 per 1000 catheter days. The mean number of catheter days prior to developing an infection was 210 days (range 17 to 373 days). A single microorganism caused 86% of infections, with Coagulase negative staphylococcus (n¼2) and Enterococcus faecalis (n¼2) the most frequent. There was one fungal infection with Candida albicans. Rates of line salvage were low with only one line being able to be salvaged with antibiotics (14.2%) with 6/7 episodes requiring a line removal and new line insertion. Other non-infective line complications included one line fracture and one line blockage due to a thrombin plug. These data demonstrate successful set up of an HPN service, with low overall mortality. Our high rate of reconstructive surgery is secondary to a large cohort who present with vascular complications, as we are a tertiary Vascular Surgery centre for the South East region. Overall our line infection rates are in keeping with ESPEN guidelines but are higher than other reported series, and our line salvage rates are low. We aim to improve both these areas in the future by introducing; single lumen Hickman lines only when possible; use of Taurolidine line locks and formulation of line salvage guidelines at our trust. 1. ESPEN Guidelines on Parenteral Nutrition: Home Parenteral Nutrition (HPN) in adult patients. Clinical Nutrition28 (2009) 467-479 2. Home Parenteral Nutrition Outcome: 3 decades of experience from a single centre. DDW 2013 abstract no. 1305
e201
There was no correlation between lifestyle factors and number of CRBSI, r¼0.01, P¼0.4. In the year prior to reassessment the number of CRBSI per patient was 1-3, mean 1.6, mode 1. In the year after it was 0-2, mean 0.5, mode 0. This was not statistically significant P¼0.1. While the reduction in CRBSI episodes following tailored advice was not statistically significant, detailed reassessment identified many areas of non adherence suggesting periodic re-evaluation is of use.
3. Allen JD, Giordano T, Kevil CG. Nitrite and nitric oxide metabolism in peripheral artery disease. Nitric Oxide. 2012;26: 217-222. 4. Presley TD, Morgan AR, Bechtold E, et al. Acute effect of a high nitrate diet on brain perfusion in older adults. Nitric Oxide. 2011;24:34-42. 5. Schiffer T, Weitzberg E, Lundberg JO, & Larsen FJ. Dietary inorganic nitrate reduces basal metabolic rate in man. Nitric Oxide. 2013;31: 546.
OC55. DIETARY NITRATE e AN UNRECOGNIZED NUTRIENT?
OC56. OUTCOME OF THE FIRST TWENTY PATIENTS IN A HOME PARENTERAL NUTRITION (HPN) SERVICE AT GUYS AND ST. THOMAS' HOSPITAL
A. Ashworth, S.J. Bailey, G.M. Hayward, F. DiMenna, A. Vanhatalo, A.M. Jones. Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Heavitree Road, Exeter, EX1 2 LU, UK Nitric oxide (NO), a powerful signalling molecule, regulates vascular flow, blood pressure, and tissue responses to hypoxia. Previous research suggested that NO is derived from endogenous synthesis via the conversion of L-arginine to L-citrulline, which is oxygen dependent. Recent research has demonstrated the important role of exogenous synthesis, via consumption of dietary nitrate (NO3), which may subsequently be converted to nitrite (NO2) and NO in hypoxic conditions1. Dietary nitrate supplements reduce blood pressure2, improve exercise tolerance in peripheral arterial disease3, improve cerebral perfusion in older adults4 and reduce oxidative stress markers5. However, nitrate is a strictly controlled, environmental contaminant and not regarded as a nutrient essential for health. Plasma [nitrate] and [nitrite] increase after dietary nitrate supplements such as beetroot juice and sodium nitrate, but few studies have used whole, high nitrate vegetables to supplement a normal diet. The purpose of this study was to identify the effects of supplementation with high and low nitrate vegetables on plasma [nitrate], [nitrite], and blood pressure (BP) in a randomized, crossover trial. Fifteen non-smoking, physically active males, 18-40 years, were recruited from the University of Exeter, from January 2011 to March 2012. Participants received either high or low nitrate vegetables for 2-week periods, with a 2-week ‘wash out’ in between. The results indicated significant main and interaction effects of dietary nitrate intake on plasma [nitrate] (P < 0.05) and plasma [nitrite] (P < 0.05). Post hoc tests revealed that supplementation with high nitrate vegetables significantly increased plasma [nitrate] (baseline: 29.5 ± 20.0 mM; after high nitrate vegetables: 129.4 ± 87.1 mM, P < 0.05) and plasma [nitrite] (baseline: 118.9 ± 35.2 nM; after high nitrate vegetables: 226.5 ± 89.3 nM, P < 0.05). Mean systolic BP, diastolic BP and mean arterial pressure were reduced by 3 mmHg, (statistically non-significant), after consumption of high nitrate vegetables. There was no reduction in BP after eating low nitrate vegetables. There were significant correlations between changes in plasma [nitrate], [nitrite] and BP, indicating that as plasma [nitrate] and [nitrite] increased, systolic BP, diastolic BP and mean arterial pressure were reduced. In conclusion, supplementation with high nitrate vegetables increased plasma [nitrate] and [nitrite], which correlated significantly with changes in BP. These findings challenge existing dogma and support the need for research to establish dietary nitrate as a future nutrient in clinical nutrition, both in therapeutics and prevention of disease.
Correlation between changes in variables > high nitrate vegetables
Statistics*
Significance (P)
Systolic BP and [nitrate] Diastolic BP and [nitrite] Mean arterial blood pressure and [nitrate]
r ¼ e .49 r ¼ e .56 r ¼ e .44
0.03 0.02 0.05
*Pearson’s correlation coefficient, where r ¼ .50 indicates large effect size
1. Lundberg JO, Weitzberg E, Gladwin MT. The nitrate-nitrite-nitric oxide pathway in physiology and therapeutics. Nat Rev Drug Disc. 2008;7:156167. 2. Siervo M, Lara J, Ogbonmwan I, Mathers JC. Inorganic nitrate and beetroot juice supplementation reduces blood pressure in adults: a systematic review and meta-analysis. J Nutr. 2013;143:818-26.
M. McCarthy 1, J.M. Dunn 1, S. O'Sullivan 1, S. Fong 1, H. Al-Hilou 1, J. Le Couteur 2, A. White 2, C. Coker 3, C. Pool 3, A. Williams 4, V. Datta 4. 1Department of Gastroenterology Lambeth Palace Road, London SE1 7EH, UK; 2Nutrition and Dietetics department Lambeth Palace Road, London SE1 7EH, UK; 3Pharmacy department Lambeth Palace Road, London SE1 7EH, UK; 4Department of Colorectal Surgery at Guys and St. Thomas’ NHS Foundation Trust, Lambeth Palace Road, London SE1 7EH, UK A Home Parenteral Nutrition (HPN) service was set up at Guy’s and St. Thomas’ Hospitals in August 2010, to meet the demands of treating Intestinal Failure (IF) in the South East region, particularly secondary to the emergence of a tertiary vascular centre at our trust. We present outcome data for the first 3 years. Data were collected from consecutive patients on HPN from medical records and stored in a prospective database. Twenty patients (12 male) have been treated with HPN. Mean age is 53 years (range 22 to 76 years). Indications for HPN were acute bowel ischaemia n¼6, acute bowel ischaemia and enterocutaneous fistula (ECF) n¼3, ECF alone n¼3 (2 had Crohn’s disease), perforated diverticular disease n¼1, small bowel perforation due to lymphoma n¼1, high output ileostomy n¼4 (3 had underlying malignancy), gastric outlet obstruction with distal jejunal structuring n¼1 and chronic pseudo-obstruction n¼1.The mean HPN duration was 225.9 days (range 7 days to 952 days) Overall survival at time of reporting was 75% (15/20). Of these 15, 47% (7/15) have undergone reconstructive surgery and a further 33% (5/15) are awaiting surgery. The remaining 20% (3/15) are Type 3 IF patients that are jointly followed with St Marks’ IF Unit. Of the 5 patients who have died, 1 had come off HPN successfully but died 9 months later from complications from his multiple myeloma. The remaining 4 patients died on HPN, 3 secondary to malignancy and 1 from catastrophic extension of gut ischaemia secondary to Degos disease. 5/20 (25%) patients had a documented catheter related blood stream infection (CRBSI). There were 7 episodes, (3 had a single infection, 2 had 2 infections). This gave an overall infection rate of 1.5 per 1000 catheter days. The mean number of catheter days prior to developing an infection was 210 days (range 17 to 373 days). A single microorganism caused 86% of infections, with Coagulase negative staphylococcus (n¼2) and Enterococcus faecalis (n¼2) the most frequent. There was one fungal infection with Candida albicans. Rates of line salvage were low with only one line being able to be salvaged with antibiotics (14.2%) with 6/7 episodes requiring a line removal and new line insertion. Other non-infective line complications included one line fracture and one line blockage due to a thrombin plug. These data demonstrate successful set up of an HPN service, with low overall mortality. Our high rate of reconstructive surgery is secondary to a large cohort who present with vascular complications, as we are a tertiary Vascular Surgery centre for the South East region. Overall our line infection rates are in keeping with ESPEN guidelines but are higher than other reported series, and our line salvage rates are low. We aim to improve both these areas in the future by introducing; single lumen Hickman lines only when possible; use of Taurolidine line locks and formulation of line salvage guidelines at our trust. 1. ESPEN Guidelines on Parenteral Nutrition: Home Parenteral Nutrition (HPN) in adult patients. Clinical Nutrition28 (2009) 467-479 2. Home Parenteral Nutrition Outcome: 3 decades of experience from a single centre. DDW 2013 abstract no. 1305