Faster rehabilitation weight gain during childhood is associated with risk of non-communicable disease in adult survivors of severe acute malnutrition

Nutritional rehabilitation during severe acute malnutrition (SAM) aims to quickly restore body size and minimize poor short-term outcomes. We hypothesized that faster weight gain during treatment is associated with greater cardiometabolic risk in adult life. Anthropometry, body composition (DEXA), blood pressure, blood glucose, insulin and lipids were measured in a cohort of adults who were hospitalized as children for SAM between 1963 and 1993. Weight and height measured during hospitalization and at one year post-recovery were abstracted from hospital records. Childhood weight gain during nutritional rehabilitation and weight and height gain one year post-recovery were analysed as continuous variables, quintiles and latent classes in age, sex and minimum weight-for-age z-scores-adjusted regression models against adult measurements. Data for 278 adult SAM survivors who had childhood admission records were analysed. Of these adults, 85 also had data collected 1 year post-hospitalisation. Sixty percent of participants were male, mean (SD) age was 28.2 (7.7) years, mean (SD) BMI was 23.6 (5.2) kg/m2. Mean admission age for SAM was 10.9 months (range 0.3-36.3 months), 77% were wasted (weight-for-height z-scores<-2). Mean rehabilitation weight gain (SD) was 10.1 (3.8) g/kg/day and 61.6 (25.3) g/day. Rehabilitation weight gain > 12.9 g/kg/day was associated with higher adult BMI (difference = 0.5 kg/m2, 95% CI: 0.1-0.9, p = 0.02), waist circumference (difference = 1.4 cm, 95% CI: 0.4-2.4, p = 0.005), fat mass (difference = 1.1 kg, 95% CI: 0.2-2, p = 0.02), fat mass index (difference = 0.32kg/m2, 95% CI: -0.0001-0.6, p = 0.05), and android fat mass (difference = 0.09 kg, 95% CI: 0.01-0.2, p = 0.03). Post-recovery weight gain (g/kg/month) was associated with lean mass (difference = 1.3 kg, 95% CI: 0.3-2.4, p = 0.015) and inversely associated with android-gynoid fat ratio (difference = -0.03, 95% CI: -0.07to-0.001 p = 0.045). Rehabilitation weight gain exceeding 13g/kg/day was associated with adult adiposity in young, normal-weight adult SAM survivors. This challenges existing guidelines for treating malnutrition and warrants further studies aiming at optimising these targets.

Micronutrient Status in Adult Crohn's Disease during Clinical Remission: A Systematic Review

Adults with Crohn's disease (CD) may be at risk of micronutrient insufficiency in clinical remission through restrictive eating, malabsorption, abnormal losses or inflammation. This systematic review synthesises the literature on micronutrient insufficiency in CD in clinical remission in terms of the prevalence of low circulating micronutrient concentrations and as a comparison against a healthy control (HC). Studies were included if the population was predominantly in remission. A total of 42 studies met the inclusion criteria; 12 were rated as low quality, leaving 30 studies covering 21 micronutrients of medium/high quality that were included in the synthesis. Vitamins D and B12 were the most frequently reported nutrients (8 and 11); there were few eligible studies for the remaining micronutrients. The prevalence studies were consistent in reporting individuals with low Vitamins A, B6, B12 and C, β-carotene, D, Magnesium, Selenium and Zinc. The comparator studies were inconsistent in finding differences with CD populations; Vitamin D, the most reported nutrient, was only lower than the HC in one-quarter of the studies. Adult CD populations are likely to contain individuals with low levels of one or more micronutrients, with the most substantial evidence for Vitamins D and B12. The studies on other micronutrients are of insufficient number, standardisation and quality to inform practice.

Individualised Exercise Training Enhances Antioxidant Buffering Capacity in Idiopathic Pulmonary Fibrosis

Exercise training is recommended for patients with idiopathic pulmonary fibrosis (IPF); however, the mechanism(s) underlying its physiological benefits remain unclear. We investigated the effects of an individualised aerobic interval training programme on exercise capacity and redox status in IPF patients. IPF patients were recruited prospectively to an 8-week, twice-weekly cardiopulmonary exercise test (CPET)-derived structured responsive exercise training programme (SRETP). Systemic redox status was assessed pre- and post-CPET at baseline and following SRETP completion. An age- and sex-matched non-IPF control cohort was recruited for baseline comparison only. At baseline, IPF patients (n = 15) had evidence of increased oxidative stress compared with the controls as judged by; the plasma reduced/oxidised glutathione ratio (median, control 1856 vs. IPF 736 p = 0.046). Eleven IPF patients completed the SRETP (median adherence 88%). Following SRETP completion, there was a significant improvement in exercise capacity assessed via the constant work-rate endurance time (+82%, p = 0.003). This was accompanied by an improvement in post-exercise redox status (in favour of antioxidants) assessed via serum total free thiols (median increase, +0.26 μmol/g protein p = 0.005) and total glutathione concentration (+0.73 μM p = 0.03), as well as a decrease in post-exercise lipid peroxidation products (-1.20 μM p = 0.02). Following SRETP completion, post-exercise circulating nitrite concentrations were significantly lower compared with baseline (-0.39 μM p = 0.04), suggestive of exercise-induced nitrite utilisation. The SRETP increased both endurance time and systemic antioxidant capacity in IPF patients. The observed reduction in nitrite concentrations provides a mechanistic rationale to investigate nitrite/nitrate supplementation in IPF patients.

Detecting low-intake dehydration using bioelectrical impedance analysis in older adults in acute care settings: a systematic review

BACKGROUND

Dehydration is a frequent cause of excess morbidity and poor health outcomes, particularly in older adults who have an increased risk of fluid loss due to renal senescence, comorbidities, and polypharmacy. Detecting dehydration is key to instigating treatment to resolve the problem and prevent further adverse consequences; however, current approaches to diagnosis are unreliable and, as a result, under-detection remains a widespread problem. This systematic review sought to explore the value of bioelectrical impedance in detecting low-intake dehydration among older adults admitted to acute care settings.

METHODS

A literature search using MEDLINE, EMBASE, CINAHL, Web of Science, and the Cochrane Library was undertaken from inception till May 2022 and led to the eventual evaluation of four studies. Risk of bias was assessed using the Cochrane tool for observational studies; three studies had a high risk of bias, and one had a low risk. Data were extracted using systematic proofs. Due to insufficient reporting, the data were analysed using narrative synthesis.

RESULTS

One study showed that the sensitivity and specificity of bioelectrical impedance in detecting low-intake dehydration varied considerably depending on the total body water percentage threshold used to ascertain dehydration status. Other included studies supported the technique's utility when compared to conventional measures of hydration status.

CONCLUSIONS

Given the scarcity of literature and inconsistency between findings, it is not possible to ascertain the value of bioelectrical impedance for detecting low-intake dehydration in older inpatients.

Systems redox biology in health and disease

Living organisms need to be able to cope with environmental challenges and other stressors and mount adequate responses that are as varied as the spectrum of those challenges. Understanding how the multi-layered biological stress responses become integrated across and between different levels of organization within an organism can provide a different perspective on the nature and inter-relationship of complex systems in health and disease. We here compare two concepts which have been very influential in stress research: Selye's 'General Adaptation Syndrome' and Sies's 'Oxidative Stress' paradigm. We show that both can be embraced within a more general framework of 'change and response'. The 'Reactive Species Interactome' allows each of these to be considered as distinct but complementary aspects of the same system, representative of roles at different levels of organization within a functional hierarchy. The versatile chemistry of sulfur - exemplified by hydrogen sulfide, glutathione and proteinous cysteine thiols - enriched by its interactions with reactive oxygen, nitrogen and sulfur species, would seem to sit at the heart of the 'Redox Code' and underpin the ability of complex organisms to cope with stress.

Body composition and chemotherapy toxicity in women with early breast cancer (CANDO-3): protocol for an observational cohort study

INTRODUCTION

Systemic anticancer therapy is given to selected patients with early breast cancer (EBC) before or after surgery with the aim of eradicating micrometastatic spread and reducing the risk of cancer recurrence. Chemotherapy treatment is most effective when patients receive the optimum dose, on time and without delays or reductions in their treatment doses. Most chemotherapy drugs are dosed according to body surface area calculated from a patient's height and weight. These calculations were however designed based on data from normal weight patients. This has resulted in uncertainty as to the optimal dosing for patients with different amounts of blood, muscle and fatty tissue (body composition). This study uses segmental bioelectrical impedance analysis (using the Seca mBCA 515) to determine whether differences in the measures of resistance and reactance, and derived estimates of body composition, are predictive of chemotherapy toxicity in the treatment of EBC.

METHODS AND ANALYSIS

A prospective observational cohort study of women with EBC in whom adjuvant or neoadjuvant chemotherapy is planned. A total of 300 participants will be recruited across nine UK hospital sites. The primary outcome is to determine if higher fat mass index is associated with increased National Cancer Institute Common Terminology Criteria for Adverse Events v5.0 grade 3 (or higher) chemotherapy toxicity.

ETHICS AND DISSEMINATION

This study has received ethical approval from the South Central Hampshire B Research Ethics Committee, England (19/SC/0596: IRAS: 263666). The chief investigator and coinvestigators will be responsible for publication of the study findings in a peer-reviewed journal, on behalf of all collaborators.

TRIAL REGISTRATION NUMBER

ISRCTN79577461.

Screening, assessment and management of perioperative malnutrition: a survey of UK practice

Background

Perioperative malnutrition is common and is associated with increased mortality, complications and healthcare costs. Patients having surgery for cancer and gastro-intestinal disease are at particular risk. It is a modifiable pre-operative risk factor and perioperative clinicians are well placed to identify those at risk and instigate interventions shown to improve outcome. Thus, we conducted a survey of Perioperative Medicine Leads with the aim of assessing the current provision of nutritional screening and intervention pathways in the UK.

Methods

Perioperative Medicine Leads registered with the Royal College of Anaesthetists were asked to complete an online survey exploring current practice in screening, assessment and management of malnutrition in the perioperative period. The survey included a mixture of open and closed questions, graded response questions and options for free text. Where a response was not received, departments were phoned directly and e-mails sent to non-responders.

Results

We received 121 completed questionnaires from 167 Perioperative Medicine Leads (response rate of 72.5%). Seventy respondents (57.9%) reported using the Malnutrition Universal Screening Tool to screen patients; however, only 61 (50.4%) referred patients at nutritional risk onto a dietitian. Sixty (49.6%) lacked confidence in local ability to identify and manage malnutrition perioperatively, with 28 (23.1%) reporting having a structured pathway for managing malnourished patients. One hundred eleven respondents (91.7%) agreed that malnutrition impacts on quality of life after surgery and 105 (86.8%) felt adopting a standard protocol would improve outcomes for patients. Those reporting a lack of confidence in dealing with malnutrition perioperatively cited a lack of organisational support, patients being seen too close to surgery and lack of clarity around responsibility as key reasons for difficulties in managing this group of patients.

Conclusions

Malnutrition in the perioperative period is a modifiable risk factor which is common and results in increased morbidity for patients and increased cost to healthcare systems. This survey highlights areas of practice where perioperative clinicians can improve the assessment and management of patients at nutritional risk prior to elective surgery.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13741-021-00196-2.

Current Landscape of Nutrition Within Prehabilitation Oncology Research: A Scoping Review

Background: Prehabilitation aims to improve functional capacity prior to cancer treatment to achieve better psychosocial and clinical outcomes. Prehabilitation interventions vary considerably in design and delivery. In order to identify gaps in knowledge and facilitate the design of future studies, we undertook a scoping review of prehabilitation studies to map the range of work on prehabilitation being carried out in any cancer type and with a particular focus on diet or nutrition interventions. Objectives: Firstly, to describe the type of prehabilitation programs currently being conducted. Secondly, to describe the extent to which prehabilitation studies involved aspects of nutrition, including assessment, interventions, implementation, and outcomes. Eligibility Criteria: Any study of quantitative or qualitative design that employed a formal prehabilitation program before cancer treatment ("prehabilitation" listed in keywords, title, or abstract). Sources of Evidence: Search was conducted in July 2020 using MEDLINE, PubMed, EMBASE, EMCARE, CINAHL, and AMED. Charting Methods: Quantitative data were reported as frequencies. Qualitative nutrition data were charted using a framework analysis that reflects the Nutrition Care Process Model: assessment, intervention, and monitoring/evaluation of the nutrition intervention. Results: Five hundred fifty unique articles were identified: 110 studies met inclusion criteria of a formal prehabilitation study in oncology. prehabilitation studies were mostly cohort studies (41%) or randomized-controlled trials (38%) of multimodal (49%), or exercise-only (44%) interventions that were applied before surgery (94%). Nutrition assessment was inconsistently applied across these studies, and often conducted without validated tools (46%). Of the 110 studies, 37 (34%) included a nutrition treatment component. Half of these studies provided the goal for the nutrition component of their prehabilitation program; of these goals, less than half referenced accepted nutrition guidelines in surgery or oncology. Nutrition interventions largely consisted of counseling with dietary supplementation. The nutrition intervention was indiscernible in 24% of studies. Two-thirds of studies did not monitor the nutrition intervention nor evaluate nutrition outcomes. Conclusion: Prehabilitation literature lacks standardized and validated nutritional assessment, is frequently conducted without evidence-based nutrition interventions, and is typically implemented without monitoring the nutrition intervention or evaluating the intervention's contribution to outcomes. We suggest that the development of a core outcome set could improve the quality of the studies, enable pooling of evidence, and address some of the research gaps identified.

The use of bioelectrical impedance analysis to predict post-operative complications in adult patients having surgery for cancer: A systematic review

BACKGROUND

Patients undergoing surgery for cancer are at particular risk of post-operative complications. The pre-operative period is an opportunity to identify and mitigate risk factors and improve outcome. Bioelectrical impedance analysis (BIA) may offer an additional means of identifying patients at risk of post-operative morbidity.

AIMS

The aim of this systematic review was to assess the use of measures and estimates of body composition determined by BIA as markers of peri-operative risk in adult patients undergoing elective surgery for cancer.

METHODS

This review was performed in accordance with the PRISMA guidelines. The electronic databases of MEDLINE, EMBASE, CINAHL, CENTRAL and the Web of Science were searched from inception. Studies of adult participants having elective surgery for cancer were included if participants underwent BIA in the peri-operative period and were assessed for post-operative complications.

RESULTS

2578 studies were identified, of which 12 were eligible for inclusion. In total the studies report data from 1508 subjects. Five studies examined phase angle or standardized phase angle, six examined derived measures and one examined both. Eight of the 12 demonstrated an association between phase angle and/or body composition and an increased risk of post-operative complications.

CONCLUSIONS

Bioelectrical impedance analysis in the peri-operative period may be useful in predicting the risk of complications following elective cancer surgery. Phase angle more consistently demonstrates an association than derived estimates. Further high quality studies are needed and should report the raw impedance values, standardized phase angle and the equations used to derive body composition.

The Redox architecture of physiological function

The ability of organisms to accommodate variations in metabolic need and environmental conditions is essential for their survival. However, an explanation is lacking as to how the necessary accommodations in response to these challenges are organized and coordinated from (sub)cellular to higher-level physiological functions, especially in mammals. We propose that the chemistry that enables coordination and synchronization of these processes dates to the origins of Life. We offer a conceptual framework based upon the nature of electron exchange (Redox) processes that co-evolved with biological complexification, giving rise to a multi-layered system in which intra/intercellular and inter-organ exchange processes essential to sensing and adaptation stay fully synchronized. Our analysis explains why Redox is both the lingua franca and the mechanism that enable integration by connecting the various elements of regulatory processes. We here define these interactions across levels of organization as the 'Redox Interactome'. This framework provides novel insight into the chemical and biological basis of Redox signalling and may explain the recent convergence of metabolism, bioenergetics, and inflammation as well as the relationship between Redox stress and human disease.

Drivers of year-to-year variation in exacerbation frequency of COPD: analysis of the AERIS cohort

The association between exacerbation aetiology and exacerbation frequency is poorly understood. We analysed 2-year follow-up data from a prospective observational study of patients with chronic obstructive pulmonary disease (COPD) (www.clinicaltrials.gov identifier number NCT01360398) to evaluate year-to-year variation in exacerbation frequency and related aetiology. A total of 127 patients underwent blood and sputum sampling monthly and at exacerbation to detect respiratory infections and eosinophilic inflammation; 103 continued into year 2 and 88 completed both years. The most common bacterial species at stable state and exacerbation was Haemophilus influenzae. Among infrequent exacerbators (one exacerbation per year), the incidence of viral infection at exacerbation was high (60.0% (95% CI 35.1-81.7%) in year 1 and 78.6% (53.4-94.2%) in year 2). Those with more frequent exacerbations tended to have higher relative incidence of bacterial than viral infection. Patients with at least two additional exacerbations in year 2 versus year 1 had a higher risk of H. influenzae colonisation at stable state than those with at least two fewer exacerbations, as detected by culture (OR 1.43 (95% CI 0.71-2.91) versus 0.63 (0.40-1.01), p=0.06) and PCR (1.76 (95% CI 0.88-3.51) versus 0.56 (0.37-0.86), p<0.01). This was not seen with other infection types or eosinophilic inflammation. Analysis of the same cohort over 2 years showed, for the first time, that changes in yearly COPD exacerbation rate may be associated with variations in H. influenzae colonisation.

Impact and associations of eosinophilic inflammation in COPD: analysis of the AERIS cohort

Eosinophilic inflammation in chronic obstructive pulmonary disease (COPD) predicts response to treatment, especially corticosteroids. We studied the nature of eosinophilic inflammation in COPD prospectively to examine the stability of this phenotype and its dynamics across exacerbations, and its associations with clinical phenotype, exacerbations and infection.127 patients aged 40-85 years with moderate to very severe COPD underwent repeated blood and sputum sampling at stable visits and within 72 h of exacerbation for 1 year.Blood eosinophils ≥2% was prevalent at baseline, and predicted both predominantly raised stable-state eosinophils across the year (area under the curve 0.841, 95% CI 0.755-0.928) and increased risk of eosinophilic inflammation at exacerbation (OR 9.16; p<0.001). Eosinophils ≥2% at exacerbation and eosinophil predominance at stable visits were associated with a lower risk of bacterial presence at exacerbation (OR 0.49; p=0.049 and OR 0.25; p=0.065, respectively). Bacterial infection at exacerbation was highly seasonal (winter versus summer OR 4.74; p=0.011) in predominantly eosinophilic patients.Eosinophilic inflammation is a common and stable phenotype in COPD. Blood eosinophil counts in the stable state can predict the nature of inflammation at future exacerbations, which when combined with an understanding of seasonal variation provides the basis for the development of new treatment paradigms for this important condition.

Nutrition Issues in Pediatric Crohn's Disease

Twenty-five percent of inflammatory bowel disease (IBD) diagnoses present in childhood, with Crohn's disease (CD) being the most common type. Many children have poor nutrition status at presentation of the disease, which may worsen during the clinical course, with a significant number of children having impaired linear growth. The cause of this poor nutrition status is complex, and contributing factors include inadequate intake, malabsorption, altered energy demands, and losses through stool, particularly in colitis. The principal aim of medical management is to induce disease remission, with minimal side effects, thereby enabling normal growth and development. This must include active consideration of the nutrition needs of such children and how they may be best met. However, our understanding of the manner in which the disease process affects the energy demands of children with CD or how poor nutrition, in turn, may affect the disease course is limited. This may constrain the efficacy and effectiveness of standard therapeutic approaches to care. This review explores the many factors of relevance in the delivery of nutrition support to children with inflammatory bowel disease, and explores the role of exclusive enteral nutrition as a corticosteroid-sparing strategy to induce remission in children with active Crohn's disease.

Mechanical Energy Changes and the Oxygen Cost of Running

The relationship between the oxygen cost of running at submaximal speeds and running mechanics was investigated in a group of trained athletes by means of an energy analysis.

Subjects were filmed while running on a motorized treadmill at speeds of 3.58, 4.02, 4.47, 4.92, 5.36, and 5.81 m/s. Segmental potential and kinetic energies were determined using a three-dimensional link-segmental model. Intra-stride changes in the energy of the whole body were computed with no allowance for energy transfer and with various energy transfer constraints imposed on the model. Oxygen consumption was determined by expired air analysis and used to estimate energy expenditure.

For each transfer condition, net energy expenditure was more highly correlated with the magnitude of intra-stride energy changes than with running speed per se. The more economic running patterns were characterized by greater within-segment energy transfers.

Given the limitations of the kinematic energy model, it is suggested that individual patterns of running are a significant factor in the determination of energy expenditure.

Postprandial effects of long-term niacin/laropiprant use on glucose and lipid metabolism and on cardiovascular risk in patients with polycystic ovary syndrome

AIM

This study investigated the effect of long-term niacin/laropiprant therapy on CV risk and IR in obese women with PCOS.

METHODS

In this double-blind randomized placebo-controlled trial, 13 and 12 PCOS women completed a 12 week course of niacin/laropiprant or placebo, respectively. Fasted subjects had an endothelial function test (EndoPat2000) and then consumed a mixed meal with blood sampled postprandially for 6 h before and after intervention.

RESULTS

By 12 weeks, niacin/laropiprant lowered low-density lipoprotein cholesterol (LDL-c) (13%) and increased HDL-c (17%). Despite a reduction in fasting triglycerides (21%), the drug had no effect on their postprandial rise (2.69 ± 1.44 vs. 2.49 ± 1.14 mmol/l, p = 0.72). However, following the mixed meal, plasma glucose area under the response curve increased from 13.1 ± 2.9 to 14.0 ± 2.8 mmol/l, p = 0.05, as a consequence of both increased insulin resistance [HOMA-IR: 2.2 (1.2, 4.2) vs. 3.8(1.3, 5.5), p = 0.02] and a reduced acute insulin response to glucose [424 (211, 975) vs. 257(122, 418) pmol/mmol, p = 0.04]. Niacin/laropiprant did not improve RHI (1.97 ± 0.40 vs. 2.05 ± 0.58, p = 0.33) or hsCRP.

CONCLUSIONS

In PCOS, niacin/laropiprant had a significant negative impact on postprandial glucose and no improvement in postprandial hypertriglyceridaemia, with at least the former mediated through increased IR and reduced β-cell function. This data may help explain why the improvement in fasting lipids has not translated into improved CV risk markers in PCOS.

The 'not so short-bowel syndrome': potential health problems in patients with an ileostomy

AIM

The study aimed to determine whether an ileostomy compromises nutritional, hydration and electrolyte status and bone mineral density.

METHOD

Body weight, body mass index (BMI) and fat and lean body mass (LBM) were measured in 60 patients with an ileostomy [14 small-bowel resection (SBR); 46 non-small-bowel resection (NSBR)] and in 60 age- and sex-matched normal controls. Measurement of plasma sodium, potassium, calcium, magnesium, urea and creatinine and 24-h urinary output of water, Na, K, Ca and Mg was made in 45 NSBR and 14 SBR ileostomists and in all the controls. Forty-six NSBR and 13 SBR ileostomists had bone mineral density (BMD) measurements of lumbar spine (LS) and femoral neck (FN).

RESULTS

The body weight of ileostomists was less than controls [median 67.8 (36.4-115.1) vs 77.7 (48.0-103.3) kg; P < 0.05]. BMI was also less [25.0 (14.3-43.0) vs 27.3 (20.2-32.2) kg/m(2) ; P < 0.05] with a lower LBM [47.8 (19.3-73.0) vs 52.9 (34.0-73.8) kg; P < 0.05]. The 24-h urinary output of the ileostomists was lower than for controls [1380 (430-4690) vs 2000 (840-4440) ml/24 h; P < 0.05] suggesting some degree of dehydration. In 62.7% of ileostomists 24-h urinary Na excretion was < 100 mmol/day vs 16.7% of controls, and ileostomists with lower urinary Na were more likely than ileostomists with normal Na excretion to have a low BMI [23.9 (14.3-33.0) vs 28.4 (16.6-43.0) kg/m(2) ; P < 0.001] and LBM [44.1 (19.3-73.0) vs 59.5 (36.6-67.9) kg; P < 0.001]. The respective 24-h output of Ca was [2.2 (0-6.1) vs 4.7 (0-13) mmol; P < 0.001] and Mg was [2.0 (0-13.7) vs 3.9 (1.2-5.4) mmol; P < 0.001], and BMD Z-score LS was -0.15 (-2.0 to 5.2) vs 0.3 (-2.5 to 2.1), Z-score FN -0.5 (-1.9 to 3.1) vs 0.2 (-1.2 to 1.4), both P < 0.05.

CONCLUSION

Patients with an ileostomy tend to have low body weight, BMI, LBM and BMD. They also tend to have low urine volumes, and some are depleted of Na, Ca and Mg. Abnormalities are greater in those with a lower urinary Na and measuring this will identify ileostomists at risk of Na depletion who will be benefitted by Na supplements.

Clinical utility of 13C-liver-function breath tests for assessment of hepatic function

13C-Liver-function breath tests have been used in clinical diagnostics and, to a limited extent, to investigate hepatic function. From a practical perspective, tests such as the 13C-aminopyrine and 13C-methacetin breath tests are simple to administer, safe, and relatively inexpensive to perform. Surprisingly, they have not entered the mainstream of clinical practice, because they are perceived to lack the specificity and adequate precision needed to give accurate results in real time. The dynamic nature of 13C-liver-function breath tests, their possible versatility in terms of assessing a range of different liver functions, and the ease with which they can be repeated to follow relative changes in liver function with time, all imply the potential for wider clinical application. Therefore, there is a need for these tests to be critically evaluated and their potential clinical application be tested systematically against defined objectives. We describe refinements in the methodology of the tests and propose several situations in which currently reliable methods for assessment of liver function do not exist and where 13C-liver-function breath tests might be of use. We propose that use has been constrained by practical methodological considerations which could be addressed to offer tests better suited to routine application in the out-patient or community setting.

Preterm birth and body composition at term equivalent age: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Infants born preterm are significantly lighter and shorter on reaching term equivalent age (TEA) than are those born at term, but the relation with body composition is less clear. We conducted a systematic review to assess the body composition at TEA of infants born preterm.

METHODS

The databases MEDLINE, Embase, CINAHL, HMIC, "Web of Science," and "CSA Conference Papers Index" were searched between 1947 and June 2011, with selective citation and reference searching. Included studies had to have directly compared measures of body composition at TEA in preterm infants and infants born full-term. Data on body composition, anthropometry, and birth details were extracted from each article.

RESULTS

Eight studies (733 infants) fulfilled the inclusion criteria. Mean gestational age and weight at birth were 30.0 weeks and 1.18 kg in the preterm group and 39.6 weeks and 3.41 kg in the term group, respectively. Meta-analysis showed that the preterm infants had a greater percentage total body fat at TEA than those born full-term (mean difference, 3%; P = .03), less fat mass (mean difference, 50 g; P = .03), and much less fat-free mass (mean difference, 460 g; P < .0001).

CONCLUSIONS

The body composition at TEA of infants born preterm is different than that of infants born at term. Preterm infants have less lean tissue but more similar fat mass. There is a need to determine whether improved nutritional management can enhance lean tissue acquisition, which indicates a need for measures of body composition in addition to routine anthropometry.

Paediatric nutrition risk scores in clinical practice: children with inflammatory bowel disease

BACKGROUND

There has been increasing interest in the use of nutrition risk assessment tools in paediatrics to identify those who need nutrition support. Four non-disease specific screening tools have been developed, although there is a paucity of data on their application in clinical practice and the degree of inter-tool agreement.

METHODS

The concurrent validity of four nutrition screening tools [Screening Tool for the Assessment of Malnutrition in Paediatrics (STAMP), Screening Tool for Risk On Nutritional status and Growth (STRONGkids), Paediatric Yorkhill Malnutrition Score (PYMS) and Simple Paediatric Nutrition Risk Score (PNRS)] was examined in 46 children with inflammatory bowel disease. Degree of malnutrition was determined by anthropometry alone using World Health Organization International Classification of Diseases (ICD-10) criteria.

RESULTS

There was good agreement between STAMP, STRONGkids and PNRS (kappa > 0.6) but there was only modest agreement between PYMS and the other scores (kappa = 0.3). No children scored low risk with STAMP, STRONGkids or PNRS; however, 23 children scored low risk with PYMS. There was no agreement between the risk tools and the degree of malnutrition based on anthropometric data (kappa < 0.1). Three children had anthropometry consistent with malnutrition and these were all scored high risk. Four children had body mass index SD scores < -2, one of which was scored at low nutrition risk.

CONCLUSIONS

The relevance of nutrition screening tools for children with chronic disease is unclear. In addition, there is the potential to under recognise nutritional impairment (and therefore nutritional risk) in children with inflammatory bowel disease.

Energy expenditure, nutrition and growth

Fundamental to appropriate nutritional prescription is an understanding of the conditions necessary for growth that include the requirements for energy in health and illness. Energy requirements need to be met by the dietary intake to prevent weight loss. A positive energy balance will result in weight gain. Energy requirement includes several components; the largest is the basal metabolic rate, although physical activity level and the energy needs of growth are important components. All aspects of energy metabolism are likely to be influenced by illness and impact on energy balance. Changes in dietary intake and physical activity are observed clinically but poorly described in most childhood illnesses. Changes in metabolic rate are poorly described in part owing to methodological problems. This review explores changes in energy expenditure associated with health and disease, highlights the lack of evidence underpinning this aspect of practical nutritional support and provides the clinician with a guide to the factors involved in estimating energy requirements, emphasising the importance of measuring the child's response to nutritional support.

Body composition in childhood inflammatory bowel disease

BACKGROUND & AIMS

Little is known about the impact of disease and treatment on the pattern of growth in children with Inflammatory Bowel Disease (IBD). Significant deficits in height and weight in children with Crohn's disease have been reported but changes in fat and fat free mass are less well defined. This study aims to describe the height, weight and body composition of a cohort of children with IBD.

METHODS

Height, weight, skinfold thicknesses and bioelectrical impedance analysis was performed. Disease activity was assessed with clinical scoring systems.

RESULTS

55 children, median age 13.7 years (range 6.5-17.7) were studied. Median (25th, 75th percentile) Standard Deviation Score for BMI, Height and Weight were - 0.3 (- 0.97, 0.65), - 0.56 (- 1.42, 0.06), - 0.62 (- 1.43, 0.19). In Crohn's disease, using multiple regression analysis disease activity measured by PCDAI was significantly inversely related to fat free mass (β - 0.2, 95% CI -0.17, -0.03, p 0.005).

CONCLUSIONS

Children with IBD were both under and overweight. Nutritional deficits were more common in Crohn's disease. Fat free mass was related to disease activity in children with Crohn's disease regardless of changes in weight. Weight or BMI may mask deficits in lean tissue in the presence of normal or increased proportions of body fat.

Accelerometers for measuring physical activity behavior in Indian children

OBJECTIVE

To examine the validity of accelerometers for characterizing habitual physical activity patterns in Indian children.

DESIGN

Cohort study.

SETTING

Holdsworth Memorial Hospital, Mysore.

SUBJECTS

Children (N=103, mean age 6.6 years) selected from an ongoing birth cohort study.

METHODS

Physical activity was measured over 7 days using accelerometers (MTI Actigraph) and concurrent parent-maintained activity diaries. Actigraph counts per minute representing sedentary (<10), light (< 400), moderate (<3000) and vigorous activity were determined using a structured activity session in a separate group of 10 children. In 46 children chosen for validating accelerometers, time spent in different activity levels according to diaries was determined. Energy Expenditure (EE) was calculated from diaries using a factorial method.

RESULTS

Ninety-eight children wore the monitor for > or = 4 days. Total counts and time spent in different activity levels were similar in boys and girls (P>0.2). Among 46 children chosen for comparisons, time spent in sedentary (r =0.48, P=0.001), light (r=0.70, P<0.001) and moderate activities (r=0.29, P=0.054) according to diaries correlated with those derived from counts, and total Actigraph counts correlated with EE (r=0.42, P=0.004). Bland-Altman analysis showed systematic bias, and wide limits of agreement between these methods for time spent in different activity levels.

CONCLUSIONS

Accelerometers are a well tolerated and objective way of measuring activity behavior in free-living children. Though accelerometer counts correlate with time spent in activity of varying intensity and energy expenditure derived from parent-maintained diaries, wide limits of agreement show that the limitations of accelerometers need to be recognized in interpreting the data that they generate.

Transfer of15N from oral lactose-ureide to lysine in normal adults

The metabolic fate of salvaged urea-nitrogen was explored in normal adults who had consumed a diet that provided 36 g protein/day for 7 days. We hypothesised that the colonic microflora utilise nitrogen derived from urea salvage to synthesise lysine in functionally significant amounts for the host. Oral lactose-[(15)N(15)N]ureide is resistant to digestion but is fermented by the colonic microflora to release (15)NH3, which can be used for amino acid synthesis. Prime and intermittent oral doses of lactose-[(15)N(15)N]ureide were ingested for 18 h, urine was collected every 3 h and stools were collected for a further 2 days. Amino acids were isolated from urine and from faecal bacterial protein and the enrichment measured. Compared with baseline values, there was significant enrichment (atoms per cent excess) in faecal bacterial glycine (0.0526), alanine (0.117), lysine (0.0875) and histidine (0.0487), and in urinary glycine (0.016), alanine (0.0144) and lysine (0.0098), but not hisitidine. These data show that the gastrointestinal bacteria can utilise urea-nitrogen in the formation of essential and non-essential amino acids that are available to the host. We estimate that on this low protein diet the amount of lysine from bacterial synthesis and available to the host may be 30 mg/kg/day. These data have important implications for our current perceptions for the dietary requirements for essential amino acids.

Tissue-specific stable isotope measurements of postprandial lipid metabolism in familial combined hyperlipidaemia

OBJECTIVE

The metabolic defects underlying familial combined hyperlipidaemia (FCHL) are not clearly understood. We used stable isotope techniques combined with tissue-specific measurements in adipose tissue and forearm muscle to investigate fatty acid handling by these tissues in the fasting and postprandial states.

RESULTS

Patients were insulin resistant as shown by higher glucose and insulin concentrations and lower muscle glucose extraction than controls. Plasma triacylglycerol (TAG) concentrations were higher in patients. Adipose tissue TAG extraction was not lower in patients than controls, although TAG clearance was lower, probably representing saturation. Following a test meal, patients showed a greater increase in chylomicron-TAG concentrations. There were no differences between FCHL patients and controls in postprandial suppression of non-esterified fatty acid (NEFA) concentrations or postprandial NEFA release, but patients had greater trapping of exogenous fatty acids in adipose tissue. 3-Hydroxybutyrate concentrations were lower in patients indicative of decreased hepatic fatty acid oxidation.

CONCLUSIONS

In this group of patients with FCHL, the major defect appeared to be overproduction of TAG by the liver due to decreased fatty acid oxidation, with fatty acids directed to TAG synthesis. We found no evidence of decreased lipoprotein lipase action or impaired fatty acid re-esterification in adipose tissue.

Professional regulation of nutritionists: where are we now?

Waterlow's (1981) Sixth Boyd Orr Lecture on a 'crisis of identity for nutrition' stimulated the Nutrition Society's drive to professionalisation. Twenty-five years on, the Society begins a new stage; first, towards an independent voluntary regulator, and then towards statutory regulation. It is timely to reflect on progress and identify the remaining challenges. The Society has made impressive progress as a voluntary regulator since 1991 when the Institute of Biology opened a register in cooperation with the Institute of Food Science and Technology and the Nutrition Society; the present register is 2.75-fold larger. The Society has specialist standards for course accreditation that enable graduates to apply for direct entry to the register, having met standards of competency in nutrition or public health nutrition. A code of ethics and a statement of professional conduct underpin a functioning system for oversight and governance that protects the public, the hallmark of all professions. Registered nutritionists lay easy claim to a unique science basis for their profession. A scheme for continuing professional development (CPD) started in July 2006, 1 year before a sample audit starts to show the link between CPD and re-registration. The scheme will be piloted in the first year. The critical challenge is the issue of identity. Waterlow (1981) stated that professional registration must lead explicitly and formally to a specific vocation, an occupation that provides services that society requires and one that contributes to the well-being and health of all. The present time may be the last and best chance for nutritionists, as nutrition has a higher priority for government in the UK than ever before. The Society has begun to help in strategic public health workforce planning and development; new and still plastic, it is the ideal locus from which a discipline and a profession can emerge. The CPD scheme will work if it helps nutritionists meet their own needs; more mutual cooperation and consensus about real world standards of performance are needed. Nutritionists need to show how they actually contribute to national health and/or wealth. Then, sustained resources can be advocated for and the support of the voting public and legislators secured, without which it will not be possible to get the legal protection that is desirable for the profession.

Dietary fatty acids make a rapid and substantial contribution to VLDL-triacylglycerol in the fed state

Exaggerated postprandial lipemia is associated with coronary heart disease and type II diabetes, yet few studies have examined the effect of sequential meals on lipoprotein metabolism. We have used 13C-labeled fatty acids to trace the incorporation of fatty acid derived from a meal into apolipoprotein B-100 (apoB-100)-containing lipoproteins and plasma nonesterified fatty acids (NEFA) following two consecutive meals. Healthy volunteers (n=8) were given breakfast labeled with [1-(13)C]palmitic acid, eicosapentaenoic acid, and docosahexaenoic acid, followed 5 h later by lunch containing [1-(13)C]oleic acid. Blood samples were taken over a 9-h period. ApoB-100-containing lipoproteins were isolated by immunoaffinity chromatography. Chylomicron-triacylglycerol (TG) concentrations peaked at 195 min following breakfast but at 75 min following lunch (P<0.001). VLDL-TG concentrations, in contrast, rose to a broad peak after breakfast and then fell steadily after lunch. Breakfast markers followed chylomicron-TG concentrations and appeared in plasma NEFA with a similar profile, whereas [1-(13)C]oleic acid peaked 2 h after lunch in plasma TG and NEFA. Breakfast markers appeared steadily in VLDL, peaking 1-3 h after lunch, whereas [1-(13)C]oleic acid was still accumulating in VLDL at 9 h. Around 17% of VLDL-TG originated from recent dietary fat 5 h after breakfast, and around 40% at the end of the experiment. We conclude that there is rapid flux of fatty acids from the diet into endogenous pools. Further study of these processes may open up new targets for intervention to reduce VLDL-TG concentrations and postprandial lipemia.

Percentage of body fat and plasma glucose predict plasma sialic acid concentration in type 2 diabetes mellitus

Circulating sialic acid is an independent risk factor for cardiovascular disease and is higher in people with type 2 diabetes mellitus. Sialic acid is associated with body mass index, but it is uncertain whether body fat contributes to the higher levels of sialic acid in type 2 diabetes mellitus. Therefore, we have investigated whether the higher levels of sialic acid observed in type 2 diabetes mellitus persist when controlling for fatness. Fasting plasma samples were collected from 24 individuals with type 2 diabetes mellitus and 24 controls. Percentage of body fat was measured by bioelectrical impedance. Plasma sialic acid was quantified by an enzymatic method. Plasma sialic acid was higher in the group with type 2 diabetes mellitus than controls (602 +/- 14 vs 545 +/- 14 mg/L, P = .007). Percentage of body fat was associated with plasma sialic acid concentration in both the control group (r = 0.481, P = .020) and the group with type 2 diabetes mellitus (r = 0.527, P = .007). Fasting glucose was also associated with plasma sialic acid in the group with type 2 diabetes mellitus (r = 0.700, P < .001). Adjustment for percentage of body fat accounted for the higher levels of sialic acid in type 2 diabetes mellitus. Using linear regression, 54.3% of the variation of plasma sialic acid was explained by percentage of body fat and glucose concentrations in the whole group. Seventy-four percent of sialic acid variation was explained by the same model in type 2 diabetes mellitus. In conclusion, this is the first study to show that percentage of body fat predicts plasma sialic acid concentration and contributes toward higher levels of sialic acid in type 2 diabetes mellitus.

The benefits of oestrogens on postprandial lipid metabolism are lost in post-menopausal women with Type 2 diabetes

AIMS

Women with Type 2 diabetes appear to lose the protection against cardiovascular disease (CVD) afforded by oestrogens. We examined the effects of oestrogen hormone replacement therapy (HRT) on postprandial clearance of dietary fat in non-diabetic and diabetic post-menopausal women.

METHODS

In a cross-sectional study, fasting subjects [HRT+ and HRT- control and diabetic women; Type 2 diabetes (DM) HRT+n = 8, DM HRT-n = 14, control HRT+n = 7, control HRT-n = 11] consumed a meal containing the stable isotope 1,1,1-[13]C-tripalmitin, with blood and breath sampled for 6 and 24 h, respectively, in the postprandial period.

RESULTS

In diabetic women, there were no differences between the HRT+ and HRT- groups for any of these parameters. In contrast, in HRT+ compared with HRT- control women, the triglyceride (TG) area under the curve was lower [AUC; HRT+ median (range) 7.7 (4.1, 12.8) mmol/l per 6 h, HRT- 9.7 (3.9, 18.5) mmol/l per 6 h, P < 0.05] and [13]C-palmitic acid in the TG fraction was also lower [HRT+ 23.2 (10.3, 41.3) ng/ml per 6 h, HRT- 47.7 (12.6, 77.2) ng/ml per 6 h, P < 0.05], suggesting the lower postprandial triglyceridaemia associated with HRT in non-diabetic women is because of better chylomicron clearance.

CONCLUSIONS

The oestrogen-associated advantage in clearance of dietary lipid we observed in non-diabetic post-menopausal women is not seen in post-menopausal diabetic women. This is likely to promote an atherogenic lipoprotein profile and may contribute to the loss of CVD protection seen in diabetic women.

Variation in [U-13C] alpha linolenic acid absorption, beta-oxidation and conversion to docosahexaenoic acid in the pre-term infant fed a DHA-enriched formula

Docosahexaenoic acid (DHA) is an integral component of neural cell membranes and is critical to the development and function of the CNS. A premature delivery interrupts normal placental supply of DHA such that the infant is dependent on the nature of the nutritional support offered. The most abundant omega-3 fatty acid in pre-term formulas is alpha linolenic acid (ALNA), the precursor of DHA. This project studied the absorption, beta-oxidation and conversion of ALNA to DHA by pre-term infants ranging from 30-37 wk of corrected gestation. [U-(13)C] ALNA was administered emulsified with a pre-term formula to 20 well pre-term infants on full enteral feeds. Enrichment of (13)C in stool and as (13)CO(2) in breath was used to estimate absorption across the gut and partitioning toward beta-oxidation respectively. Excretion of the administered dose of (13)C in stool ranged from 2.0 to 26.2%; excretion decreased with increasing birth gestation. Appearance as (13)CO(2) on breath ranged from 7.6 to 19.0%. All infants synthesised eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and DHA with the least mature having the highest cumulative plasma DHA. These results show considerable variation suggesting that the worst absorption of ALNA and the greatest production of DHA occur in infants born at the earliest gestation.

Docosahexaenoic acid is selectively enriched in plasma phospholipids during pregnancy in Trinidadian women – Results of a pilot study

The fetal demand for docosahexaenoic acid (DHA) has to be satisfied by the mother. We determined the fatty acids in maternal plasma non-esterified fatty acid (NEFA), triacylglycerol (TAG) and phosphatidylcholine (PC), in a cross-sectional study of non-pregnant (n = 10), pregnant (n = 19), and postpartum (n = 9) women. There were lipid class-dependent differences in plasma polyunsaturated fatty acid (PUFA) concentrations between groups. During pregnancy, DHA was most highly enriched in PC, about 230%, with more modest enrichment for linoleic acid (LA) and arachidonic acid (AA), and no enrichment of alpha-linolenic acid (alpha-LNA). There was relative enrichment of LA, AA and alpha-LNA in TAG, but not of DHA. There was no specific enrichment of any PUFA in the NEFA pool. These data accord with the suggestion that the enrichment of alpha-LNA in TAG and of DHA in phospholipids reflects hepatic regulation of n-3 PUFA metabolism which potentially enhances the delivery of DHA to the placenta.

High-dose fish oil and antioxidants in Crohn's disease and the response of bone turnover: a randomised controlled trial

Crohn's disease is associated with altered bone turnover that may be influenced by nutritional status, the systemic inflammatory response, cytokine production by circulating (peripheral blood) mononuclear cells (PBMC) and antioxidant micronutrient intake. High-dose fish oil is associated with reductions in disease relapse and inflammatory markers, and modulates PBMC function. The effect of fish oil plus antioxidants on bone turnover and PBMC function (the production of interferon-gamma and prostaglandin E2) in Crohn's disease was investigated in a randomised-controlled trial. Patients with currently or recently raised biochemical markers of inflammation (C-reactive protein > or = 6.9 mg/l or erythrocyte sedimentation rate > or =18 mm/h) received fish oil (providing 2.7 g/d EPA and DHA) and antioxidants (vitamins A, C and E, and Se) (n 31) or placebo (n 30) for 24 weeks. Bone turnover was assessed by measuring the concentrations of urinary deoxypyridinoline (bone resorption) and serum osteocalcin (bone formation). Fish oil plus antioxidants were associated with increases in EPA, DHA Se in plasma (all P < 0.01), and with a reduction in interferon-gamma production by mitogen-stimulated PBMC, which demonstrated a negative correlation with deoxypyridinoline/creatinine:osteocalcin ratio (r - 0.33, P = 0.009). There were no differences between the groups at 24 weeks in the response of deoxypyridinoline or osteocalcin or their ratio, or in nutritional status. Dietary supplementation in Crohn's disease with high intakes of EPA and DHA, as fish oil, plus antioxidants was associated with a modulated production of interferon-gamma by PBMC but not altered indices of bone turnover.

Measured versus predicted energy expenditure in children with inactive Crohn's disease

INTRODUCTION

The aim of the study was to assess if the estimated average requirements for energy for normal children (EAR) and the Schofield equation could reliably predict energy requirements in children with inactive Crohn's disease (CD).

METHODS

Twenty-three children with inactive CD were studied, median age 14.3 years (range 7.8-16.9). Resting energy expenditure (REE) was measured by indirect calorimetry and compared with that predicted using the Schofield equation (BMR). Total energy expenditure (TEE) was measured using REE and a 3-day activity diary and compared with EAR.

RESULTS

REE ranged from 79% to 136% of BMR. Mean REE was not significantly greater than mean BMR (P=0.25 2-tailed t-test). TEE ranged from 72% to 163% of estimated average requirements for energy for children of that weight (EARw). EARw tended to underestimate TEE in large children and overestimate TEE in small children (Bland-Altman plot R=0.5, P=0.002). EARw was a poor predictor of TEE (R=0.35, P=0.1). EAR underestimated energy requirements by >500 kcal/day in 40% of the children.

CONCLUSIONS

The Schofield equation and EAR are unreliable methods of predicting total energy requirements in children with inactive CD with a significant potential to underestimate energy needs. When energy requirements were greater than EAR it was due to physical activity and body habitus rather than raised REE.

Peripheral blood mononuclear cell fatty acid composition and inflammatory mediator production in adult Crohn's disease

BACKGROUND & AIMS

Crohn's disease (CD) is associated with nutritional deficiencies, altered plasma concentrations of polyunsaturated fatty acids (PUFA) and an anti-inflammatory response to fish oil that contains n-3 PUFA. This suggests that, in CD, immune cells may have altered n-3 PUFA composition with functional consequences. The aim of this study is to investigate n-3 and n-6 PUFA composition and synthetic function of peripheral blood mononuclear cells (PBMC) in the basal state.

METHODS

A case control study of 52 adult CD patients and healthy, age- and sex-matched controls. Composition of PBMC and plasma phospholipids were measured by gas chromatography and production of tumour necrosis factor-alpha, prostaglandin E2 (PGE2) and interferon-gamma (IFN-gamma) by PBMC were measured by ELISA.

RESULTS

CD was associated with higher concentrations of eicosapentaenoic acid and other n-3 PUFA, and lower arachidonic acid (AA) (n-6 PUFA) in PBMC. This was not explained by differences in dietary fat intake. Lower rates of production of PGE2 and IFN-gamma by PBMC were noted in quiescent and active CD, respectively, compared to controls.

CONCLUSIONS

CD is associated with a greater availability, and not a deficiency, of n-3 PUFA in PBMC, but lower concentrations of AA, and lower rates of production of PGE2 and IFN-gamma, compared to healthy controls.

Is there a case for n-3 fatty acid supplementation in cystic fibrosis?

PURPOSE OF REVIEW

This review evaluates our current knowledge on the association of fatty acid abnormalities in cystic fibrosis with the disease process, and makes a case for a well-designed clinical trial to evaluate the clinical efficacy of long chain n-3 fatty acids.

RECENT FINDINGS

It has long been known that cystic fibrosis patients exhibit fatty acid abnormalities, but these have not been well investigated in tissues affected by the disease. Recent studies have demonstrated that such tissues do indeed show abnormalities in the proportions of linoleic, arachidonic and docosahexaenoic acids, and have demonstrated alterations in fatty acid and phospholipid metabolism in cystic fibrosis. Work in other areas has identified novel anti-inflammatory actions of long chain n-3 fatty acids that might be relevant to cystic fibrosis. A recent systematic review of fish oil supplementation in cystic fibrosis did not allow firm conclusions to be drawn, but suggested that there may be some benefits.

SUMMARY

The restoration of abnormal fatty acid profiles may be beneficial in cystic fibrosis, but this approach has not been evaluated in studies with a suitable design to permit firm conclusions to be drawn. There is a need for a long-term randomized controlled study to evaluate the therapeutic benefit of fish oil supplementation in cystic fibrosis.

Fish oil and antioxidants alter the composition and function of circulating mononuclear cells in Crohn disease

BACKGROUND

Crohn disease (CD) is associated with osteoporosis and other extraintestinal manifestations that might be mediated by cytokines from circulating (peripheral blood) mononuclear cells (PBMCs). Fish oil rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) reduces disease activity in patients with CD with raised laboratory markers of inflammation and in healthy subjects alters PBMC function.

OBJECTIVE

We investigated the effect of fish oil plus antioxidants on cytokine production by PBMCs from patients with CD with raised C-reactive protein concentrations (>/=6.9 mg/L) or erythrocyte sedimentation rates (>/=18 mm/h).

DESIGN

A randomized placebo-controlled trial of fish oil (2.7 g EPA and DHA/d; n = 31) or placebo (olive oil; n = 31) for 24 wk was conducted in patients with CD. The fish-oil group additionally received an antioxidant preparation (vitamins A, C, and E and selenium). Exclusion criteria included corticosteroid use. Fatty acid composition was measured by gas chromatography. Production of tumor necrosis factor alpha, interferon gamma (IFN-gamma), and prostaglandin E(2) (PGE(2)) was measured by enzyme-linked immunosorbent assays after stimulation with mitogen and endotoxin (lipopolysaccharide).

RESULTS

Fish-oil plus antioxidant dietary supplementation was associated with higher EPA and DHA incorporation into PBMCs (P < 0.001) and lower arachidonic acid (P = 0.006) and lower production of IFN-gamma by mitogen-stimulated PBMCs (P = 0.012) and of PGE(2) by lipopolysaccharide-stimulated PBMCs (P = 0.047).

CONCLUSION

Dietary supplementation with fish oil plus antioxidants is associated with modified PBMC composition and lower production of PGE(2) and IFN-gamma by circulating monocytes or macrophages. The response of extraintestinal manifestations of CD should be investigated in a randomized controlled trial.

Maldigestion and malabsorption of 13C labelled tripalmitin in gastrostomy-fed patients with cystic fibrosis

BACKGROUND & AIMS

Some patients with cystic fibrosis continue to have excessive losses of stool lipid, despite the use of pancreatic enzyme replacement therapy to improve digestion. The aim of this study was to explore the residual capacity of the gastrointestinal tract to digest and absorb dietary lipid using stable isotopic methodology in ten patients with cystic fibrosis who were gastrostomy fed in comparison to eight healthy children. We sought to test the hypothesis that a reduction in the availability of dietary lipid may arise from malabsorption of the products of digestion, rather than maldigestion alone.

METHODS

All subjects consumed [1,1,1-(13)C] tripalmitin (10mg/kg body weight) with a standardised meal but the patients with cystic fibrosis did not take their habitual pancreatic enzymes. Total enrichment of (13)C was measured by isotope ratio mass spectrometry in stools collected over 3 days. Maldigestion and malabsorption was differentiated by measuring (13)C-label excretion in stool triglyceride and fatty acid fractions, respectively.

RESULTS

The patients with cystic fibrosis had elevated (13)C-label losses in total stools (56.7%, 6.8-77.9%)(median and range; % administered dose), triglyceride (6.6%, 0-31.2%) and fatty acid (16.7%, 3.4-50.3%) fractions compared to healthy children (1.9%, 0-10.9%, P<0.001; triglyceride: 0.2%, 0-0.6%, p<0.01; fatty acid 0.9%, 0-6.5%, P<0.001).

CONCLUSIONS

These results highlight differences between gastrostomy fed patients with cystic fibrosis to both digest and absorb dietary lipid. There is a need to extend these observations and apply this approach to patients both with and without pancreatic enzyme replacement therapy.

Laboratory markers predict bone loss in Crohn's disease: relationship to blood mononuclear cell function and nutritional status

BACKGROUND

Crohn's disease is associated with reduced bone density. The power of simple markers of systemic inflammation to identify higher rates of bone loss, in Crohn's disease, is uncertain. This relationship and the role of circulating (peripheral blood) mononuclear cells were investigated in a case-control study.

METHODS

Urinary deoxypyridinoline/creatinine and serum osteocalcin concentrations were compared in male and premenopausal females with "active" Crohn's disease (C-reactive protein > or = 10 and/or erythrocyte sedimentation rate > or = 20) (n = 22) and controls with "quiescent" Crohn's disease (C-reactive protein < 10 and erythrocyte sedimentation rate < 20) (n = 21). No patients were receiving corticosteroid therapy. Production of tumour necrosis factor-alpha, interferon-gamma and prostaglandin E(2) by peripheral blood mononuclear cells were measured.

RESULTS

Active Crohn's disease was associated with a higher deoxypyridinoline/creatinine (P = 0.02) and deoxypyridinoline/creatinine:osteocalcin ratio (P =0.01) compared with quiescent Crohn's disease, but similar osteocalcin (P = 0.24). These were not explained by vitamin D status, dietary intake or nutritional status. However, production of interferon-gamma by concanavalin A-stimulated peripheral blood mononuclear cells was lower in active Crohn's disease (P = 0.02) and correlated negatively with the deoxypyridinoline/creatinine:osteocalcin ratio (r = -0.40, P = 0.004).

CONCLUSION

In Crohn's disease, raised C-reactive protein and erythrocyte sedimentation rate may indicate higher rates of bone loss and, if persistent, the need to assess bone mass even where disease symptoms are mild. This may be partly explained by altered production of interferon-gamma by peripheral blood mononuclear cells.

Effect of meal sequence on postprandial lipid, glucose and insulin responses in young men

OBJECTIVE

To investigate whether the postprandial changes in plasma triacylglycerol (TAG), nonesterified fatty acids (NEFA), glucose and insulin concentrations in young men were the same if an identical meal was fed at breakfast and lunch, and if the response to lunch was modified by consumption of breakfast.

METHODS

In two trials (1 and 2) healthy subjects (age 22+/-1 y, body mass index 22+/-2 kg/m(2)) were fed the same mixed macronutrient meal at breakfast at 08:00 h and lunch at 14:00 h. In the third trial, no breakfast was fed and the overnight fast extended until lunch at 14:00 h. Addition of [1,1,1-(13)C]tripalmitin to one meal in each trial was used to distinguish between endogenous and meal-derived lipids.

RESULTS

The postprandial changes in TAG, NEFA and glucose concentrations were similar in trials 1 and 2. The change in plasma total TAG concentration was about two fold less (P<0.05) after lunch compared to breakfast. Postprandial NEFA suppression was the same after breakfast and lunch. Glucose and insulin responses were significantly greater following lunch suggesting decreasing insulin sensitivity during the day. Consumption of breakfast did not alter the postprandial total TAG or NEFA responses after lunch. Measurement of [(13)C]palmitic acid concentration showed that handling of TAG and NEFA from the meal was the same after breakfast and lunch, and was not altered by consumption of breakfast.

CONCLUSIONS

Overall, these data suggest that in young, healthy men regulation of plasma TAG from endogenous sources, principally VLDL, but not chylomicrons during the postprandial period leads to differences in the magnitude of lipaemic response when the same meal was consumed at breakfast or at lunch 6 h later.

Premenopausal advantages in postprandial lipid metabolism are lost in women with type 2 diabetes

OBJECTIVE

Women with type 2 diabetes appear to lose the protection against cardiovascular disease afforded by estrogens. We examined the effects of menopausal status on postprandial clearance of dietary fat in healthy and diabetic women.

RESEARCH DESIGN AND METHODS

Fasting subjects (premenopausal and postmenopausal control subjects, premenopausal and postmenopausal diabetic women, all n = 8) were given a meal containing the stable isotope 1,1,1-(13)C-tripalmitin, with blood and breath sampled for 6 and 24 h, respectively, in the postprandial period. Lower levels of (13)C-palmitic acid ((13)C-PA) in the triglyceride fraction implies more efficient chylomicron clearance, lower levels of (13)C-PA in the nonesterified fatty acid (NEFA) fraction implies improved dietary NEFA entrapment, and higher levels of (13)CO(2) in the breath denote more efficient of oxidation of dietary-derived lipid.

RESULTS

In diabetic women, there were no differences between the pre- and postmenopausal groups for any of these parameters. In contrast, premenopausal control subjects, compared with postmenopausal control subjects, had lower (13)C-PA in the triglyceride fraction area under the curve (AUC) (premenopausal median [range] 25.2 [12.1-49.4 mmol/l] per 6 h, postmenopausal 48.5 [15.5-77.2 mmol/l] per 6 h; P < 0.01) and higher (13)CO(2) levels in the breath AUC (premenopausal 22.5 [18.0-31.5%] of administered dose, postmenopausal 17.2 [11.2-31.5%] of administered dose; P < 0.01) with no difference between groups in levels of (13)C-PA in the NEFA fraction AUC.

CONCLUSIONS

The premenopausal advantage in clearance of dietary lipid is not seen in premenopausal diabetic women. This is likely to promote an atherogenic lipoprotein profile and may contribute to the loss of cardiovascular disease protection seen in diabetic women.

Selective partitioning of dietary fatty acids into the VLDL TG pool in the early postprandial period

Circulating triacylglycerol (TG) arises mainly from dietary fat. However, little is known about the entry of dietary fat into the major TG pool, very low-density lipoprotein (VLDL) TG. We used a novel method to study the specific incorporation of dietary fatty acids into postprandial VLDL TG in humans. Eight healthy volunteers (age 25.4 +/- 2.2 years, body mass index 22.1 +/- 2.3 kg/m2) were fed a mixed meal containing 30 g fish oil and 600 mg [1-13C]palmitic acid. Chylomicrons and VLDL were separated using immunoaffinity against apolipoprotein B-100. The fatty acid composition of lipoproteins was analyzed by gas chromatography/mass spectrometry. [1-13C]palmitic acid started to appear in VLDL TG 3 h after meal intake, and a similar delay was observed for eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Approximately 20% of dietary fatty acids entered the VLDL TG pool 6 h after meal intake. DHA was clearly overincorporated into this pool compared with [1-13C]palmitic acid and EPA. This seemed to depend on a marked elevation of this fatty acid in the nonesterified fatty acid pool. In summary, the contribution of dietary fatty acids to early postprandial VLDL TG is substantial. The role of DHA in VLDL TG production will require further investigation.

Conversion of alpha-linolenic acid to palmitic, palmitoleic, stearic and oleic acids in men and women

The purpose of this study was to determine whether adult humans can recycle carbon from alpha-linolenic acid (18:3n-3) into saturated (SFA) and monounsaturated (MUFA) fatty acids. Six men and six women consumed 700 mg [U-13C]-18:3n-3. Blood was collected over 21 days and breath over 24h. [13C]-labelled SFA and MUFA were detected in plasma phosphatidylcholine (PC) and triacylglycerol (TAG). Total labelled fatty acid incorporation into SFA and MUFA was five- and 25-fold greater in PC than TAG in men and women, respectively. [13C]-16:0 was the major labelled fatty acid in both fractions. Total [13C] incorporation into SFA and MUFA was 20% greater in men than women, and related positively (r(2) = 0.35, P<0.05) to the fractional recovery of labelled 18:3n-3 as 13CO2 on breath. These results suggest that the extent of partitioning towards beta-oxidation and carbon recycling may regulate the availability of 18:3n-3 for conversion to longer-chain fatty acids.

Prostaglandin E2 production and T cell function after fish-oil supplementation: response to antioxidant cosupplementation

BACKGROUND

Prostaglandin E(2) (PGE(2)) inhibits lymphocyte proliferation and the production of interferon-gamma (IFN-gamma) by peripheral blood mononuclear cells, but the effect of PGE(2) on interleukin 4 (IL-4) production is unclear. Fish oil, which contains eicosapentaenoic and docosahexaenoic acids, inhibits production of PGE(2). The effects of fish oil on lymphocyte proliferation and production of IFN-gamma and IL-4 are unclear and may be influenced by the availability of antioxidants.

OBJECTIVE

We investigated the effect of dietary fish oil with and without antioxidant cosupplementation on lymphocyte proliferation and the production of PGE(2), IFN-gamma, and IL-4 by peripheral blood mononuclear cells.

DESIGN

Sixteen healthy men received dietary fish-oil supplements providing 0.3, 1, and 2 g eicosapentaenoic acid plus docosahexaenoic acid/d for 4 consecutive weeks each (total of 12 wk). All subjects were randomly assigned to daily cosupplementation with either antioxidants (200 microg Se, 3 mg Mn, 30 mg RRR-alpha-tocopheryl succinate, 90 mg ascorbic acid, 450 micro g vitamin A) or placebo.

RESULTS

Fish-oil supplementation decreased PGE(2) production and increased IFN-gamma production and lymphocyte proliferation from baseline values. Cosupplementation with antioxidants did not affect cytokine production or lymphocyte proliferation.

CONCLUSION

Dietary fish oil modulates production of IFN-gamma and lymphocyte proliferation in a manner consistent with decreased production of PGE(2), but this effect is not modified by antioxidant cosupplementation.

Essential fatty acid status in paediatric Crohn's disease: relationship with disease activity and nutritional status

BACKGROUND

Active paediatric Crohn's disease is associated with nutritional deficiencies and altered nutrient intake. The availability of essential fatty acids (linoleic and alpha-linolenic acids) or their derivatives (arachidonic and eicosapentaenoic acids) may alter in plasma and cell membrane phospholipid in protein-energy malnutrition in children and in Crohn's disease in adults.

AIM

To investigate the relationship of fatty acid phospholipid profiles with disease activity and nutritional status in paediatric Crohn's disease.

METHODS

The fatty acid (proportionate) composition of plasma and erythrocyte phosphatidylcholine was determined in 30 patients (10.3-17.0 years) stratified into active and quiescent Crohn's disease (paediatric Crohn's disease activity index) and high and low body mass (body mass index centile).

RESULTS

In plasma phosphatidylcholine, active disease activity was associated with a lower level of alpha-linolenic acid compared with that in quiescent disease (P < 0.05). A body mass index below the 50th centile was associated with active Crohn's disease, low linoleic and alpha-linolenic acids and high arachidonic acid (P < 0.05) in plasma phosphatidylcholine, and low alpha-linolenic acid in erythrocyte phosphatidylcholine. These findings could not be explained through differences in habitual dietary fat intake.

CONCLUSION

In paediatric Crohn's disease, a low body mass index centile and high disease activity are associated with altered profiles of essential fatty acids and their derivatives, which may reflect altered metabolic demand.

Inhibition of tumour necrosis factor-alpha and interleukin 6 production by mononuclear cells following dietary fish-oil supplementation in healthy men and response to antioxidant co-supplementation

Increased dietary consumption of the n-3 polyunsaturated fatty acids (PUFA) eicosapentaenoic acid (20 : 5n-3; EPA) and docosahexaenoic acid (22 : 6n-6; DHA) is associated with their incorporation into circulating phospholipid and increased production of lipid peroxide metabolites. The relationship between peripheral blood mononuclear cell (PBMC) function, n-3 PUFA intake and antioxidant co-supplementation is poorly defined. We therefore investigated tumour necrosis factor (TNF)-alpha and interleukin (IL) 6 production by PBMC and phospholipid fatty acid composition in plasma and erythrocytes of healthy male subjects (n 16) receiving supplemental intakes of 0.3, 1.0 and 2.0 g EPA+DHA/d, as consecutive 4-week courses. All subjects were randomised in a double-blind manner to receive a concurrent antioxidant supplement (200 microg Se, 3 mg Mn, 30 mg D-alpha-tocopheryl succinate, 90 mg ascorbic acid, 450 microg vitamin A (beta-carotene and retinol)) or placebo. There was a positive dose-dependent relationship between dietary n-3 PUFA intake and EPA and DHA incorporation into plasma phosphatidylcholine and erythrocyte phosphatidylethanolamine, with a tendency towards a plateau at higher levels of intake. Production of TNF-alpha and IL-6 by PBMC decreased with increasing n-3 PUFA intake but tended towards a 'U-shaped' dose response. Both responses appeared to be augmented by antioxidant co-supplementation at intermediate supplementary n-3 PUFA intakes. Thus, increased dietary n-3 PUFA consumption resulted in defined but contrasting patterns of modulation of phospholipid fatty acid composition and PBMC function, which were further influenced by antioxidant intake.

Effect of altered dietary n-3 fatty acid intake upon plasma lipid fatty acid composition, conversion of [13C]alpha-linolenic acid to longer-chain fatty acids and partitioning towards beta-oxidation in older men

The effect of increased dietary intakes of alpha-linolenic acid (ALNA) or eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) for 2 months upon plasma lipid composition and capacity for conversion of ALNA to longer-chain metabolites was investigated in healthy men (52 (SD 12) years). After a 4-week baseline period when the subjects substituted a control spread, a test meal containing [U-(13)C]ALNA (700 mg) was consumed to measure conversion to EPA, docosapentaenoic acid (DPA) and DHA over 48 h. Subjects were then randomised to one of three groups for 8 weeks before repeating the tracer study: (1) continued on same intake (control, n 5); (2) increased ALNA intake (10 g/d, n 4); (3) increased EPA+DHA intake (1.5 g/d, n 5). At baseline, apparent fractional conversion of labelled ALNA was: EPA 2.80, DPA 1.20 and DHA 0.04 %. After 8 weeks on the control diet, plasma lipid composition and [(13)C]ALNA conversion remained unchanged compared with baseline. The high-ALNA diet resulted in raised plasma triacylglycerol-EPA and -DPA concentrations and phosphatidylcholine-EPA concentration, whilst [(13)C]ALNA conversion was similar to baseline. The high-(EPA+DHA) diet raised plasma phosphatidylcholine-EPA and -DHA concentrations, decreased [(13)C]ALNA conversion to EPA (2-fold) and DPA (4-fold), whilst [(13)C]ALNA conversion to DHA was unchanged. The dietary interventions did not alter partitioning of ALNA towards beta-oxidation. The present results indicate ALNA conversion was down-regulated by increased product (EPA+DHA) availability, but was not up-regulated by increased substrate (ALNA) consumption. This suggests regulation of ALNA conversion may limit the influence of variations in dietary n-3 fatty acid intake on plasma lipid compositions.

Chylomicron particle size and number, factor VII activation and dietary monounsaturated fatty acids

This study evaluated the effects of substituting dietary saturated fatty acids (SFAs) with monounsaturated fatty acids (MUFAs) on postprandial chylomicron (triacylglycerol (TAG), apolipoprotein B-48 (apo B-48) and retinyl ester (RE)), chylomicron particle size and factor VII (FVII) response when subjects were given a standard meal. In a controlled sequential design, 51 healthy young subjects followed an SFA-rich diet (Reference diet) for 8 weeks after which half of the subjects followed a moderate MUFA diet (n=25) and half followed a high MUFA diet (n=26) for 16 weeks. Fasting lipoprotein and lipid measurements were evaluated at baseline and at 8-week intervals during the Reference and MUFA diets. In 25 of the subjects (n=12 moderate MUFA, n=13 high MUFA), postprandial responses to a standard test meal containing RE and 13C-tripalmitin were investigated at the end of the Reference and the MUFA diet periods. Although there were no differences in the postprandial lipid markers (TAG, RE, 13C-TAG) on the two diets, the postprandial apo B-48 response (incremental area under the curve (IAUC)) was reduced by 21% on the moderate MUFA diet (NS) and by 54% on the high MUFA diet (P<0.01). The postprandial peak concentrations of apo B-48 were reduced by 33% on the moderate MUFA diet (P<0.01) and 48% on the high MUFA diet (P<0.001). Fasting values for factor VII activity (FVIIc), activated factor VII (FVIIa) or factor VII antigen (FVIIag) did not differ significantly when subjects were transferred from Reference to MUFA diets. However, the postprandial increases in coagulation FVII activity (FVIIc) were 18% lower and of activated FVII (FVIIa) were 17% lower on the moderate MUFA diet (NS). Postprandial increases in FVIIc and FVIIa were 50% (P<0.05) and 29% (P<0.07) lower on the high MUFA diet and the area under the postprandial FVIIc response curve (AUC) was also lower on the high MUFA diet (P<0.05). Significantly higher ratios of RE:apo B-48 (P<0.001) and 13C-palmitic acid:apo B-48 (P<0.01) during both MUFA diets suggest that the CMs formed carry larger amounts of dietary lipids per particle, reflecting an adaptation to form larger lipid droplets in the enterocyte when increased amounts of dietary MUFAs are fed. Smaller numbers of larger chylomicrons may explain attenuated activation of factor VII during the postprandial state when the background diet is rich in MUFA.