NNIW82 - The Importance of Nutrition as an Integral Part of Disease Management

Editor(s): Rémy F. Meier, B. Ravinder Reddy, Peter B. Soeters. Clinical Nutrition Series 82

The last decades have illuminated the important role of nutrition in the prevention and management of diseases. Despite the elaborated knowledge and discussions on the scientific podium, the role of nutrition is often overlooked in clinical practice. Unfortunately, medical nutrition is in most cases not incorporated in the curriculum at medical schools, which might lead to negative attitudes or even total neglect of the nutritional needs of hospitalized patients.


Basics in Clinical Medical Nutrition

Author(s): R. F. Meier, A. Forbes

Nutrition is a basic requirement for life and plays an important role in health and in diseaseprevention, but malnutrition is a common event and a cause of increased morbidity andmortality, particularly in patients with disease-related malnutrition showing inflammationand a catabolic state. Malnutrition is often overlooked, and deterioration in the nutritionalstatus following admission to hospital is common. It should be actively pursued by aubiquitous system of nutrition screening, and full nutritional assessment is required forthose found to be at risk. There are simple screening tools which can be used by all healthcare professionals. Assessment considers body composition, inflammatory status and otheraspects of underlying diseases and their functional consequences; it is a more specialistprocess. It is important to determine the energy and protein needs of each individualpatient. Appropriate nutritional intervention can often be offered by the oral route, usingfood with or without special supplements. When this is insufficient, enteral tube feedingwill normally be sufficient, but there is an important subgroup of patients in whom enteralfeeding is contraindicated or unsuccessful, and in these patients parenteral nutrition(either total or supplemental) is required. A number of immunonutrients and other specialsubstrates have been shown to be helpful in specific circumstances, but their use is notwithout potential hazards, and therefore adherence to international guidelines is recommended.

Macronutrient Metabolism in Starvation and Stress

Author(s): P. B. Soeters

In starvation and to a lesser extent in stress starvation, the loss of protein mass is sparedas much as possible. This metabolic arrangement must have developed under the influenceof evolutionary pressure in view of the importance of protein mass for function andlongevity. Peripheral adipose tissue mass is only limiting when its mass is extremely small.Protein is the predominant precursor of glucose in (stress) starvation and glucose is anessential substrate for the synthesis and maintenance of cells and matrix and for the controlof the redox state. To spare protein, glucose should be used efficiently only for thosepurposes that cannot be achieved by fat. It is suggested that this is achieved by limitingfull glucose oxidation and increasing fatty acid and ketone body oxidation, which mostlikely can also largely cover energy needs of the central nervous system. In stress states,net negative nitrogen balance (catabolism) largely results from net losses of peripheralprotein mass, predominantly muscles, whereas central organs (e.g. the liver), the immunesystem and wound healing are anabolic. A number of factors are responsible for a netnegative nitrogen balance which may ultimately lead to death if stress persists. In stress,the amino acid mix derived from peripheral (predominantly muscle) tissues is modified ininterplay with the liver and to a minor extent the kidney. This mix is different in nonstressedconditions, containing substantially increased amounts of the nonessential aminoacids glutamine, alanine, glycine and (hydroxy)proline. Part of the amino acid skeletonsreleased by muscles are substrates to produce glucose in the liver and kidney. Glucoseand the amino acids produced especially serve as substrates for cell proliferation and matrixdeposition. The catabolic processes in peripheral tissues cannot be countered completelyby adequate nutritional support as long as stress persists. This metabolic arrangementdictates a nutritional mix containing liberal amounts of protein and carbohydratesand addition of lipids to cover energy requirements.

Noncaloric Benefits of Carbohydrates

Author(s): B. R. Reddy

Noncaloric benefits of carbohydrates are due to the presence of dietary fibers, which area heterogeneous group of natural food sources and form an important component of ahealthy diet. They differ in physiochemical properties such as solubility, fermentability andviscosity. They have a wide range of physiological effects resulting in gastrointestinal andsystemic benefits. These include appetite, satiety, bowel transit time and function, productionof short-chain fatty acids and certain vitamins, and effects on gut microbiota, immunityand inflammation, as well as mineral absorption. They also help to control theglycemic status and serum lipid levels, resulting in reduced incidence rates of atherosclerosis,hypertension, stroke and cardiovascular diseases.

The Biological Value of Protein

Author(s): D. R. Moore, P. B. Soeters

The biological value of a protein extends beyond its amino-acid composition and digestibility,and can be influenced by additional factors in a tissue-specific manner. In healthyindividuals, the slow appearance of dietary amino acids in the portal vein and subsequentlyin the systemic circulation in response to bolus protein ingestion improves nitrogen retentionand decreases urea production. This is promoted by slow absorption when onlyprotein is ingested (e.g. casein). When a full meal is ingested, whey achieves slightly betternitrogen retention than soy or casein, which is very likely achieved by its high content ofessential amino acids (especially leucine). Elderly people exhibit ‘anabolic resistance’ implyingthat more protein is required to reach maximal rates of muscle protein synthesis comparedto young individuals. Protein utilization in inflammatory or traumatic conditions increasessubstantially in the splanchnic tissues containing most of the immune system, andin wounds and growing tissues. This happens especially in the elderly, which often sufferfrom chronic inflammatory activity due to disease, physical inactivity and/or the aging processitself. Consequently, the proportion of protein absorbed in the gut and utilized formuscle protein synthesis decreases in these situations. This compromises dietary-proteininducedstimulation of muscle protein synthesis and ultimately results in increased requirementsof protein ( ∼ 1.2 g/kg body weight/day) to limit gradual muscle loss with age. Tooptimally preserve muscle mass, physical exercise is required. Exercise has both direct effectson muscle mass and health, and indirect effects by increasing the utilization of dietaryprotein (especially whey) to enhance rates of muscle protein synthesis.

Enteral Nutrition: Whom, Why, When, What and Where to Feed?

Author(s): B. R. Reddy

Oral and enteral nutrition affects both the anatomical and physiological integrity of thegastrointestinal tract. It downregulates systemic immune response, reduces overall oxidativestress and limits systemic inflammatory responses. It reduces bacterial translocation,limits pathogenic bacteria in the intestines and enables the production of shortchainfatty acids in the colon. Therefore, it is the most physiologic way of providingnutritional support in all patients. The enteral formulas are available as polymeric, semielementaland elemental diets. The beneficial effects on the gastrointestinal tract andsystemic organs of ‘early’ enteral nutrition depend on the timing, dose, location and differentmodalities of enteral delivery. Being familiar with the basic tenets of providingenteral nutrition – the ‘Who, Why, When, Where and What’ – will result in safe nutritionalinterventions and achieve a positive clinical outcome.

Management of the Metabolic Syndrome and the Obese Patient with Metabolic Disturbances: South Asian Perspective

Author(s): A. Misra, S. Bhardwaj

There is an increased prevalence of obesity and the metabolic syndrome (MS) amongSouth Asians. The phenotypes of obesity and body fat distribution are different in SouthAsians; they have high body fat, intra-abdominal and subcutaneous fat and fatty liver ata lower body mass index compared to white Caucasians; this has led to the frequent occurrenceof morbidities related to a higher magnitude of adiposity [e.g. type 2 diabetesmellitus (T2DM), hypertension (HTN) and dyslipidemia]. The increasing prevalence of obesityand related diseases in the South Asian population requires aggressive lifestyle managementincluding diet, physical activity and, sometimes, drugs. For therapeutic interventions,several drugs can be used either as mono- or combination therapy. Drugs likeorlistat, which is used for the management of obesity, also reduce the risk of T2DM. Similarly,HMG CoA reductase inhibitors decrease low-density-lipoprotein cholesterol levelsand reduce the risk of cardiovascular diseases. However, some drugs used for the treatmentof HTN (e.g. β-blockers) may increase the risk of hyperglycemia and therefore needto be used with caution. Finally, to prevent obesity, MS and T2DM among South Asians, itis particularly important to effectively implement and strengthen population-based primaryprevention strategies.

Nutritional Issues in the Short Bowel Syndrome – Total Parenteral Nutrition, Enteral Nutrition and the Role of Transplantation

Author(s): S. J. D. O' Keefe

In this review, I focus on the extreme of the short bowel syndrome where the loss of intestineis so great that patients cannot survive without intravenous feeding. This conditionis termed short bowel intestinal failure. The review outlines the principles behinddiagnosis, assessing prognosis and management. The advent of intravenous feeding (parenteralnutrition) in the 1970s enabled patients with massive (>90%) bowel resection tosurvive for the first time and to be rehabilitated back into normal life. To achieve this,central venous catheters were inserted preferably into the superior vena cava and intravenousinfusions were given overnight so that the catheter could be sealed by day inorder to maximize ambulation and social integration. However, quality of life has sufferedby the association of serious complications related to permanent catheterization – mostlyin the form of septicemias, thrombosis, metabolic intolerance and liver failure – fromthe unphysiological route of nutrient delivery. This has led to intense research into restoringgut function. In addition to dietary modifications and therapeutic suppression of motility,novel approaches have been aimed at enhancing the natural adaptation process,first with recombinant growth hormone and more recently with gut-specific glucagonlikepeptide-2 analogues, e.g. teduglutide. These approaches have met with some success,reducing the intravenous caloric needs by approximately 500 kcal/day. In controlledclinical trials, teduglutide has been shown to permit >20% reductions in intravenous requirementsin over 60% of patients after 6 months of treatment. Some patients have beenweaned, but more have been able to drop infusion days. The only approach thatNutritional Issues in the Short BowelSyndrome – Total Parenteral Nutrition,Enteral Nutrition and the Role ofTransplantationStephen J.D. O’KeefeDivision of Gastroenterology, University of Pittsburgh, Pittsburgh, PA , USA76 O’Keefepredictably can get patients with massive intestinal loss completely off parenteral nutritionis small bowel transplantation, which, if successful (1-year survival for graft and host>90%) is accompanied by dramatic improvements in quality of life.

Nutrition in Cancer

Author(s): P. Ravasco

In cancer patients, oral nutrition is the preferred route of feeding since it is a significantpart of the patient’s daily routine and contributes to the patient’s autonomy. It representsa privileged time to spend with family and friends, avoiding the tendency for isolation inthese patients. The acknowledgement that the prescribed diet is individualized, adaptedand adequate to individual needs empowers the patient with a feeling of control, and thusit is also a highly effective approach of psychological modulation. All these factors maypotentially contribute to improve the patient’s quality of life and may modulate treatmentmorbidity. The referral to a nutrition professional responsible for the individualized dietarycounseling should always be based on evidence-based decision-making plans. The implementationof individualized nutritional counseling should consider the common causesfor a poor nutritional intake in elderly cancer patients. A proper approach through counselingrequires professionals with specific experience in both nutrition and oncology. Oralnutritional supplements are a simple and practical way to meet nutritional requirementswhen normal food intake is compromised. Ideally, oral nutritional supplements should bein addition to and not instead of meals. Supplements should be administered at a timewhich does not interfere with the appetite of the patient. The administration after themeal theoretically potentiates the anabolic effect on protein metabolism. Supplementswith high energy density (>1 kcal/ml) or enriched with ω-3 fatty acid are probably themost effective.

Nutritional Therapy for Critically Ill Patients

Author(s): R. G. Martindale, M. Warren, S. Diamond, L. Kiraly

Nutrition therapy provided early in the critical care setting has been shown to improveoutcome. Appropriate and early nutrition interventions can attenuate the hyperdynamicsystemic response and depressed immune reaction to injury, serious illness and majorsurgery. Controversies limit the uniform application and potential benefits of nutrition,including failure to accurately predict who will ‘need’ nutritional intervention, lack of consensuson what the optimal enteral formulation is, overreliance on parenteral nutrition,failure to maximize the use of early enteral nutrition (EN), and how much and how best tofeed the morbidly obese population. Despite challenges and inconsistencies in today’scritical care setting, specialized nutrition has evolved from metabolic ‘support’ duringcritical illness to a primary therapeutic intervention designed, individualized and focusedto achieve metabolic optimization and mitigation of stress-induced immune and hyperdynamicsystemic responses. Nutrition should be considered early and commenced afterinitial resuscitation has taken place. This is most effectively accomplished with the use ofprotocols that aggressively promote early EN, and will result in lower mortality and a reductionin major complications. Though the complexity of the heterogeneous critically illpopulation will always be challenging, we are developing a better understanding of immunity,metabolic needs and catabolism associated with intensive care unit admissions.

Perioperative Nutritional Intervention: Where Are We?

Author(s): T. Hoos, M. Warren, R. G. Martindale

As we look forward in 2015, attention to perioperative surgical nutrition continues to playa key role in optimizing outcomes and enhancing surgical recovery. Nutrition therapiesfor preoperative preparation include high protein intake combined with exercise, immune-and metabolic-modulating nutrients, carbohydrate loading, probiotic therapy and,occasionally, the need for specialized enteral or parenteral nutrition. Early enteral nutritionand probiotic therapy optimize gastrointestinal integrity and function in the postoperativesetting. Some questions of who, when and how to optimally feed the surgical patientstill exist. Despite these questions, the abundance of evidence supports a determinedfocus for nutrition optimization prior to major surgery.

Health Economics in Medical Nutrition: An Emerging Science

Author(s): M. Nuijten

Rational: The objective of this paper is to describe the applications of health economictheory to medical nutrition. Background: The published literature provides evidence thatmedical nutrition, e.g. oral nutritional supplements, is an effective treatment for patientswith disease related malnutrition. Malnutrition is associated with mortality risk and complicationrates, including infections. Malnutrition is not a new problem and with an ageingpopulation it continues to become a major public health concern as increasing age is associatedwith an increased risk of malnutrition. Findings: This overview shows that in thecase RCTs are providing the clinical evidence, there is no methodological difference betweena cost-effectiveness analysis for pharmaceutical or nutrition. However, in nutritionthe evidence may not always come from RCT data, but will be more often based on observationaldata. Therefore the clinical evidence of nutrition in itself is not the issue, butthe handling of clinical evidence from observational studies. As the link between the consumptionof a food product and a resulting health status is often more difficult to establishthan the effect of a drug treatment it requires the further development of adapted methodologiesin order to correctly predict the impact of food-related health effects and healtheconomic outcomes from a broader perspective.

Nutrition, Frailty, Cognitive Frailty and Prevention of Disabilities with Aging

Author(s): S. Guyonnet, M. Secher, B. Vellas

Older adults can be categorized into three subgroups to better design and develop personalizedinterventions: the disabled (those needing assistance in the accomplishment ofbasic activities of daily living), the ‘frail’ (those presenting limitations and impairments inthe absence of disability) and the ‘robust’ (those without frailty or disability). However,despite evidence linking frailty with a poor outcome, frailty is not implemented clinicallyin most countries. Since many people are not identified as frail, their treatment is frequentlyinappropriate in health care settings. Assessing the frail and prefrail older adultscan no longer be delayed, we should rather act preventively before the irreversible disablingcascade is in place. Clinical characteristics of frailty such as weakness, low energy,slow walking speed, low physical activity and weight loss underline the links betweennutrition and frailty. Physical frailty is also associated with cognitive frailty. We need tobetter understand cognitive frailty, a syndrome which must be differentiated from Alzheimer’sdisease. At the Gérontopôle frailty clinics, we have found that almost 40% of thepatients referred to our center by their primary care physicians to evaluate frailty had significantweight loss in the past 3 months, 83.9% of patients presented slow gait speed,53.8% a sedentary lifestyle and 57.7% poor muscle strength. Moreover, 43 % had a MiniNutritionalAssessment less than 23.5 and 9% less than 17, which reflects protein-energyundernutrition. More than 60% had some cognitive impairment associated with physicalfrailty