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Nutritional Assessment - how to do it. April 2011

Nutritional Assessment - how to do it. April 2011. Dr Alan Stewart MB BS MRCP www.stewartnutrition.co.uk. Nutritional Assessment. “..all doctors should be able to diagnose nutritional deficiencies.” Royal College of Physicians 2002. Nutritional Assessment: What You Will Learn.

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Nutritional Assessment - how to do it. April 2011

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  1. Nutritional Assessment- how to do it.April 2011 Dr Alan Stewart MB BS MRCP www.stewartnutrition.co.uk

  2. Nutritional Assessment “..all doctors should be able to diagnose nutritional deficiencies.” Royal College of Physicians 2002

  3. Nutritional Assessment: What You Will Learn • How nutritional deficiencies develop • What are the common causes and effects of deficiency • The three key stages in Nutritional Assessment:- history- examination- investigation • A simple method of dietary assessment • The prevalence of nutritional deficiencies in the UK according to the National Diet and Nutrition Surveys • The importance of Nutritional Assessment

  4. Types of Essential Nutrients Macronutrients • Energy - provided by Carbohydrates, Fats, Protein and Alcohol • Protein – Essential and non-essential amino acid Micronutrients • Minerals: Bulk Ca, Mg, Na, K, Cl, P Trace Fe, Zn, Cu, Mn, I, Se, ? others • Vitamins: Fat-soluble A,D,E, and K Water-soluble B group and C • Essential Fatty Acids: n-3 series n-6 series

  5. Development of a Nutritional Deficiency Deficiencies evolve through five stages: • Adequacy • State of Negative Balance • Decline in Tissue Stores • Loss of Function • Death How was this arrived at?

  6. Experimental Thiamine DeficiencyBrin M. Journal of the American Medical Association 1964;187:762-766 • Group of students volunteered for a 6 week study • Normal diet but deficient in thiamin (<200ug/day, EAR 1000 ug) • Test erythrocyte thiamin pyrophosphate TPP Effect – measures increase in enzyme activity when thiamin is added to blood sample

  7. How Do Nutritional Deficiencies Develop?Adapted from Brin M 1964 Develop over days to years in a logical and recognizable sequence • State of Adequacy • State of Negative Balance • Decline in Tissue Stores • Loss of Function:1. Symptoms 2. Physical Signs 3. Organ Failure • Death

  8. Adequacy State of Negative Balance:1. Poor Intake 2. Reduced Absorption 3. Increased Losses 4. Increased Demand 5. Altered Metabolism Decline in Tissue Stores Loss of Function: 1. Symptoms 2. Physical Signs 3. Organ Failure Death This sequence evolves over:weeks (vitamin B1), months (zinc) or years (calcium and vit. B12) The causes of negative balance can be assessed or suspected from the history Tests will assess tissue levels, but not all deficiencies are clinically significant Nutritional deficiencies are most common at the extremes of age and some deterioration in nutritional state is a normal part of ageing More people will have mild symptoms of deficiency than physical signs or complete loss of function and organ failure The clinical picture of deficiency will depend on the loss of life function Development of a Nutritional Deficiency

  9. Life Functions and Nutritional Deficiency Life Functions Dysfunction caused by Deficiency • Movement Bone Fracture, Muscle Weakness • Respiration Early Muscle Fatigue • Sensitivity Neuropathy, Blindness, Reduced Intelligence • Nutrition Reduced ability to obtain food and feed self • Excretion Liver/Renal Disease • Reproduction Infertility, Miscarriage, Small-for-date Babies • Growth Infant Stunting • Defence Recurrent or Severe Infection

  10. Three Methods of Nutritional Assessment • History • Physical Examination • Laboratory Investigation

  11. The National Diet and Nutrition Surveys • Four surveys covering ages 1.5 yrs to >85 yrs • Random samples of the British population with approximately 2,000 subjects in each • Field-work conducted between 1990 and 2001 • Collected information on: - 4-7 day weighed dietary intakes- laboratory measures of nutrients- alcohol intake, supplement use- BP and BMI • No assessment of symptoms or signs of deficiency • The surveys provide useful information about the prevalence of nutritional deficiencies and the associated risk factors

  12. The Prevalence of Anaemia: NDNS • World Health Organisation Normal Ranges; 1.5-6.0 yrs >11.0g/dl, adult women >12.0g/dl, adult men >13.0g/dl. • Adult ranges have been adopted from ages 15yrs and upward • British laboratories often use a normal range of >11.5g/dl for adult women • Levels of 11.5-11.9g/dl in women can result in symptomatic iron deficiency

  13. Three Methods of Nutritional Assessment • HistoryIntake: diet + supplements Risk Factors for deficiency Symptoms of deficiency • Physical Anthropometric MeasuresExamination (Body Mass Index - kg/m2)Signs of Deficiency Signs of Underlying Disease • Laboratory Blood and Urine TestsInvestigation Bone Mineral Density X-Ray

  14. Medical Diagnosis: History is the Most Important • Both studies assessed new patients, with no clear diagnosis who were referred to a medical clinic, to determine what information was required to reach the final diagnosis • Hampton JR et al. BMJ. 1975;2:486-9 • Peterson MC et al. West Med J. 1992;156(2):163-5

  15. History: Dietary Assessment - Introduction • Not as easy (or as quick & accurate) as you might think. • Two separate questions: Is the diet healthy? Is the diet adequate? • World Health Organisation and UK Food Standards Agency set simple but varying targets for “healthy eating”. • Formal dietary assessment for adequacy involves:- prospective diet diaries for several days and - computerised analysis of macro/micronutrient intakes. • Simple assessment is needed for use in a clinic setting • Knowledge of the prevalence of deficiency (poor intakes and sub-normal test results) in the British population: National Diet and Nutrition Surveys, NDNS (1990-2003)

  16. Food Standards Agency 2006 Base your meals on starchy foods Eat appropriately for your weight Fruit and Vegetables >5 portions/day Salt <6 g/day Sugar: limit intake if overweight Saturated fats: limit intake Alcohol: Weekly targets of:<21 units for men <14 units for women Breakfast: eating it regularly helps adherence to a healthy diet and weight loss programme World Health Organisation 2008 Eat appropriately for your weight Fruit and Vegetables: have a good daily intake of fresh varieties Salt <5 g/day Sugar: limit intake of free sugars such as sucrose, fructose and glucose Saturated fats: limit intake of saturated fats which are derived mainly from animal foods andsome tropical oils Healthy Eating Guidelines

  17. Healthy Eating: EU Guidelines 2008 • Recommendations made by each country for: - Protein-rich foods: lean meat and poultry, legumes and fish- Dairy foods: milk/yoghurt and cheese- Carbohydrate-rich foods:wholegrain cereals, potato and rice - Fruit and Vegetables • Much agreement and some disagreement • These food groups provide approximately 2/3rds of essential micronutrients in the British adult diet • If an individual achieves good targets for each group then nutritional inadequacy due to poor intake is very unlikely • References: Working Document on Setting Nutrient Profiles 21/10/2008 www.food.gov.uk/multimedia/pdfs/consultation/ecsettingnp.pdf

  18. Dietary Assessment: 6 Simple Targets for AdultsTargets are adapted by the author from various sources Food Category Target Protein-rich foods >1 good portion every day Fish*>2 Portions/week including >1 Oily type/week Dairy Foods or Soya>1.5-2 Portions/day Fruit and Vegetables* >5 Portions/day Quality Carbohydrate>1-4 Portions/day and Alcohol (men/women)*<21/14 units/week * Target set by UK Food Standards Agency Other targets based on commonsense and other EU countries’ guidelines Separate assessments need to be made for fats, sugar and salt

  19. Quality Carbohydrate vs. Starchy Foods • The UK FSA advises “base your meals on starchy foods” • This advice does not address the problems of poor intakes of vitamin C, folate and fibre or emphasise the benefits of wholegrain and fibre-rich foods in reducing heart disease and cancer • Better advice is to recommend Quality Carbohydrates:wholegrain breakfast cereals from wheat, oats and otherswholemeal, granary and wheatmeal breads and chappatiwholemeal pastabrown ricefresh potatoes with their skins • Emphasising these foods as opposed to white pasta and white rice will improve nutrient intake for many in the UK • The number of daily portions, typically 1-4 per day, depends on physical activity and weight

  20. Main Food Groups: Nutrients Provided

  21. Estimated Provision of Micronutrients by Major Food GroupsPercentages of Total Dietary ProvisionAuthor’s estimated from NDNS of British Adults: Data collected 2000/1

  22. Estimated Provision of Micronutrients by Major Food GroupsTotals from: Proteins, Fish, Dairy Foods, Fruit and Vegetables and Quality Carbohydrates

  23. Prevalence of Poor Eating Habits in British AdultsAuthor’s Estimates from National Diet and Nutrition Survey 2000/1 aged 19 to 64 yearsof failure to achieve 6 Healthy Eating Targets

  24. Defining Inadequate Nutritional Intake • Nutritional deficiency can develop from a prolonged low intake • UK nutrient intake requirements are set out in the report:Dietary Reference Values for Food Energy and Nutrients for the United Kingdom (1991 – TSO) • The report defines The Lower Reference Nutrient Intake, LRNI, for protein or a vitamin or mineral as “An amount of the nutrient that is enough for only a few people in a group who have low needs”. • In practice this means that if the percentage of a population with an intake below the LRNI for a particular nutrient exceeds 3% then it is likely that a significant percentage of the population will be deficient in the nutrient

  25. NDNS: Prevalence of Deficiency - Low IntakeTotal Intakes (Food and Supplements) below LRNI for males and females • “Lower Reference Nutrient Intake – an amount of the nutrient that is enough for only the few people in a group who have low needs”. Considered to be <3% of the population • Prevalence rates >3% suggest that a significant percentage of the population could be deficient • Low iron intakes are observed in 33% of adult women of menstruating age

  26. History: Dietary Assessment - Conclusions • Formal dietary assessment is useful but time consuming • Assess the healthfulness of a person’s diet by asking about intake of: protein-rich foods, fish/oily fish, dairy foods, fruit and vegetables, quality carbohydrates and alcohol • These groups encompass 2/3rds of micronutrient intake • Failure to achieve a good standard for these food groups will alert the practitioner to a possibly inadequate intake • Separate assessments need to be made for salt, sugar and fats • Assess intake from nutritional supplements and be aware of possibly excessive intake

  27. Fragile skin Poor wound healing Apathy Wasted muscles Poor appetite Altered taste sensation Impaired swallowing Altered bowel habit Loose fitting clothes Prolonged intercurrent illness: chronic infection, chest disease, cardiac failure, cancer etc. Extremes of age Receiving benefits Living alone – especially men Alcohol, tea, coffee in excess Reduced mobility Lack of sun exposure Some drugs and multiple therapy Heavy periods History of miscarriage Recovery from illness/operation Pregnant or breastfeeding Family history/genetic factors Smoking Inappropriate use of supplements Nutritional Assessment - Risk FactorsNICE guidelines www.nice.org.uk/cg032 (2006) and others

  28. Nutritional Support in Adults [www.nice.org.uk/CG032 February 2006] Screen all patients to identify those most at risk of being deficient: • Underweight A body mass index (BMI) of less than 18.5kg/m2 • Unintentional weight lossGreater than 10% within the last 3 – 6 months or • Combination of:BMI of less than 20kg/m2 andUnintentional weight loss greater than 5% within the last 3 – 6 months Others at risk: • Those who have eaten little or nothing for more than 5 days and/or are likely to eat little or nothing for 5 days or longer • Those with a poor absorptive capacity and/or high nutrient losses and/or increased nutritional needs from causes such as catabolism • Those already identified with one deficiency e.g. anaemia or osteoporosis

  29. Prevalence of Underweight BMI <18.5 kg/m2Adults aged 16 years and older in England, 2006. NHS Information Centre

  30. Benefit Status and Micronutrient IntakePercentage of Male Population 19-64 yrs with deficient intake, <LRNI* • Data from National Diet and Nutrition Survey British Adults. TSO 2003/4 • <Lower Reference Nutrient Intakes are likely to be adequate for <3% of the population. Ref: Dietary Reference Values for Food Energy and Nutrient for the UK. HMSO 1991

  31. Benefit Status and Micronutrient IntakePercentage of Female Population 19-64 yrs with deficient intake, <LRNI* • Data from National Diet and Nutrition Survey British Adults. TSO 2003/4 • <Lower Reference Nutrient Intake are likely to be adequate for <3% of the population. Ref: Dietary Reference Values for Food Energy and Nutrient for the UK. HMSO 1991

  32. Influence of Household Income on Average Intake of Nutrients in Elderly Men [NDNS 1998] • Annual income in £000s; upper income bands are compared with lowest <4k/year • Increasing income is associated with higher intake of protein and many nutrients

  33. Educational Attainment and Nutrient Intake (LIDNS):% less intake if education < 5 GCSE grades A-C or equivalent • In males energy difference significant p <0.031; all other nutrients p <0.004 • In females all nutrients difference significant p <0.009

  34. Dental Health and Nutrient Intake (LIDNS):% difference in intake if edentate compared with dentate • NSP Non-starch polysaccharides; NMES Non-milk extrinsic sugars • No data on differences in intake of potassium, magnesium or folate were presented but are likely to be similar b to but less than those for vitamin C • Data on younger age groups were not presented

  35. Daily Alcohol Intake and Nutritional Status: NDNS 65+% difference in status compared with non/low drinkers • Intake determined from 4 day diary • Caution, no adjustment for age, health, diet or supplements was made • Non-drinkers were more likely to be older and have abnormal liver test

  36. History: Symptoms of Nutritional Deficiency • Specific SymptomsDelayed dark adaption - vitamin A or zincSore tongue - iron, vitamin B12 and other B vitamins • Non-specific Symptoms* Fatigue - anaemia, iron, potassium, magnesium, vitamins B and CCold intolerance - ironLoss of appetite - iron, vitamin B group and zincPoor immunity - protein, zinc, vitamins A and BMenstrual irregularity - protein, vitamin B12 and other nutrientsMuscle cramps and pain - potassium, magnesium and vitamin B1Numbness in feet/hands - vitamins B1, 3 and B12Mood change - vitamins C, B, folic acid and magnesiumCognitive decline - vitamins B12, B1 and B3, and n-3 essential fatty acids* Symptoms may often be due to non-nutritional causes

  37. Examination: Signs of Nutritional Deficiency • Mouth Mouth Ulcers – iron Cracking at corners of mouth – iron, vitamin B • Skin Dry scaley skin – Essential Fatty Acids Easy bruising – vitamin C • Hair Scalp hair loss – iron • Nails Spoon-shaped nails - iron • Skeleton Spinal curvature – calcium and vitamin D Low impact fracture – calcium and vitamin D • Muscle Calf muscle tenderness – vitamin B1 Loss of strength – potassium, magnesium Weak hip muscles – vitamin D • Eyes Clouding of the cornea – vitamin A • Neurological Loss of sensation in hands and feet – vitamins B1, B12 Loss of vibration sense – vitamin B12 • All the above signs also have non-nutritional causes

  38. Investigation: Laboratory Tests of Nutritional Status • GP TestsFull Blood Count red and white cells, plateletsSerum Ferritin or Serum Iron, Total Iron Binding Capacity + % satSerum Vit B12 and serum or Red Cell FolatePlasma Na, K, vitamin DBone Mineral Density (Ca) • Other TestsPlasma elements: Zn, Cu, Se, Mn, MgRed cell magnesiumVitamins B1, B2 and B6 – enzyme activationPlasma retinol, plasma or WBC vitamin CUrine Na, K, Iodine • Specialised and Rare TestsPlasma Homocysteine, MMA, Holo-transcobalamin, Enzyme testsX-rays (vitamin D and C), Brain MRI (Mn)Tissue levels – bone marrow, liver biopsy, post-mortem

  39. The Prevalence of Anaemia: NDNS • World Health Organisation Normal Ranges; 1.5-6.0 yrs >11.0g/dl, adult women >12.0g/dl, adult men >13.0g/dl. • Adult ranges have been adopted from ages 15yrs and upward • British laboratories often use a normal range of >11.5g/dl for adult women • Levels of 11.5-11.9g/dl in women can result in symptomatic iron deficiency

  40. Prevalence of Iron Deficiency: NDNSLow Plasma Ferritin: Range < 10-20ug/l • Normal ranges: infants age 1.5-4.5yrs > 10.0ug/l, females age >4yrs-adult > 15.0ug/l, males age >4yrs-adult > 20.0ug/l • Plasma ferritin can be elevated by acute or chronic inflammation, infection or liver disease and is not a reliable measure of iron status in ill and elderly people

  41. Prevalence of Vitamin B12 Deficiency: NDNS Plasma <118 pmol/l • A serum vitamin B12 of 118pmol/l is equivalent to 154pg/ml • Macrocytosis (MCV >101fl) was seen in: 1-3% of teenagers, 9% of adults, 2% of free-living elderly and 3% of elderly in institutions. • Macrocytosis is often due to alcohol excess and not vitamin B12 deficiency

  42. Prevalence of low Red Cell Folate: NDNS • The normal ranges for red cell folate and method of analysis varied with each study;infants > 400nmol/l, children and adults > 350nmol/l and the elderly > 345nmol/l • Folate status is influenced by alcohol excess and altered metabolism in the elderly • Pregnant or breast feeding women were excluded from the adult NDNS

  43. Prevalence of Vitamin C Deficiencyplasma Vit. C<11.0umol/l - NDNS data • Approx. 20% of adults and 12% of the elderly took supplements of vitamin C • Approx. 25% of British adults smoke and this declines after the age of 65 years • Aspirin was taken by 20% of free-living elderly and 24% of institutionalised elderly

  44. Nutritional Deficiencies in Acutely ill Geriatric Patients:Prevalence of Haematological Deficiencies 1973/75 • 93 acutely ill patients >65yrs: male = 35, female = 58 in Yorkshire • Folate and vitamin B12 were measured using micobiological assays • 9/93 = plasma albumin >28g/l, 29/93 = plasma albumin 28-34g/l • Refs: Morgan AG et al. Int J Vit and Nut Research. 1973:43;46-471 & 1975:45:448-462

  45. Vitamin Deficiencies in Acutely ill Geriatric Patients: Prevalence of various vitamin deficiencies 1973/75 • 93 acutely ill patients >65yrs: male = 35, female = 58 • PTT = prothrombin time (Vit K), TPP = thiamin pyrophosphate effect (vit B1)Vit B2 = whole blood riboflavin, Vit B3 = urine n-methyl nicotinamide level • References: Morgan AG et al. Int J Vit and Nut Research. 1975:45:448-462

  46. Vitamin B Deficiencies in Newly-Admitted Psychiatric Patients [Middlesex 1970s] • 154 Acute psychiatric patients with a history of poor diet: male = 52, female = 102 • Vit. B1 Def = Serum Pyruvate >79umol/l (n=154), Trans Ketolase AC > 1.3 (n=74) • Vitamin B6 deficiency = Aspartate Transaminase Activation Coefficient > 1.75 (n=66) • Reference: Carney MWP et al. British Journal of Psychiatry 1979;135: 249-54

  47. Investigation: Interpreting Nutritional Tests • There are numerous tests of nutritional status • An abnormally low result does not always mean that there is a significant deficiency • There are essentially two types of tests:- tests that measure the level of a nutrient- tests that measure the function of the nutrient • Tests that measure the level of a nutrient are:serum vitamin B12serum ferritin (iron)serum retinol • Corresponding test that measure the nutrient’s function are:serum methylmalonic acid MMA (vitamin B12)haemoglobin leveldark adaption test • Occasionally high levels of a nutrient are found • Test results must always be interpreted with knowledge of the full clinical picture of findings from history and examination

  48. Nutritional Assessment: Clinical Summary • Ask about diet: type of diet and consumption of major food groups • Ask about use of supplements • Assess risk factors: medical – unintentional weight loss, feeding difficultiesnon-medical – socioeconomic • Ask about symptoms of possible deficiency • Measure BMI and examine for signs of possible deficiency • Decide upon appropriate tests of nutritional state • Interpret data from:history, examination and investigation carefully • Treat the deficiency (diet and nutrition support) and underlying causative factors • Monitor response to treatment

  49. Treatment Plan

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