Protein-energy malnutrition (PEM)

2 forms:

• Kwashiorkor:
  • Fair-to-normal energy intake, but inadequate protein.
  • Associated with oedema and hepatomegaly.
  • Word comes from the Ghanian language, Ga, and implies "the disease that the young child develops when displaced from his mother's breast by another child or pregnancy".
• Marasmus:
  • Inadequate energy and protein intake.
  • Associated with severe wasting.

Micronutrient deficiencies

Deficiencies in iron, iodine, Vitamin A and zinc remain major public health problems in developing countries.^[2]

Epidemiology

• Globally, malnutrition is the most important risk factor for illness and death. It disproportionably affects children and pregnant women. It is the direct cause of about 300,000 deaths p.a. and indirectly responsible for about half of all deaths in young children (malnutrition increases the risk of death from diarrhoea, lower respiratory tract infection, malaria and measles).^[2]
• WHO estimates that by 2015, prevalence of malnutrition world-wide will be 17.6% - with the vast majority living in developing countries in southern Asia and sub-Saharan Africa. An additional 29% will have stunted growth due to poor nutrition.
• In the UK, malnutrition affects 10-55% ill adults in hospital and the community and, amongst hospitalised children,16% were found to be severely stunted, 14% wasted and 20% at risk of malnutrition if nutritionally stressed.^[3]
• Amongst the elderly, malnutrition affects 1% healthy individuals in the community, 4-5% patient receiving home help living at home, 20% in hospital patients, and 37% in institutionalised individuals (Swiss study).^[4]

Risk factors

In children

• Young age (<5 years) - most vulnerable are premature babies and infants at time of weaning
• Children with co-existing chronic illnesses or developmental delay
• Neglect by care-givers
• Poverty and its complex relationships with:
  • Political and economic situation
  • Education
  • Sanitation
  • Season and climatic conditions
  • Food production and security
  • Cultural and religious traditions
  • Prevalence of infectious diseases
  • Availability and effectiveness of nutrition programmes and health services

In elderly people

• Living alone
• Institutionalisation
• People with severe learning difficulties or mental health problems (depression, dementia)
• Diseases that affect appetite, eating/swallowing or GI function (gastric surgery, malabsorption, stroke, neurological disorders such as motor neurone disease)
• Catabolic states

Presentation^[5]

Presentation in adults

Adults tend to lose weight, often insidiously. Oedema may mask weight loss.

Other features may include:

• Listlessness
• Increasing fatigue
• Cold sensitivity
• Non-healing wounds and severe decubitus ulcers

Presentation in children^[2][6]

PEM:

• Poor weight gain
• Slowed linear growth
  WHO criteria for identifying children with severe malnutrition:

  • Bipedal oedema
  • Visible severe wasting
  • Weight for height > ^- 3 standard deviations from median of international reference population
• Behavioural changes - irritability, apathy, anxiety, attention deficit. Classically apathetic and quiet when lying in their bed but cry when picked up with a typical monotonous bleat or loud groan.

Three clinical syndromes (note, mixed pictures may occur):

• Marasmus:
  • Obvious loss of weight with gross reduction in muscle mass especially from limb girdles. Subcutaneous fat virtually absent.
  • Thin, atrophic skin lies in folds.
  • Pinched face has appearance of old man or monkey.
  • Alopecia and brittle hair.
  • Sometimes appearance of lanugo hair.
• Kwashiorkor:
  • Usually occurs in children aged 1-2 years with changing hair colour to red, grey or blonde.
  • Moon facies, swollen abdomen (pot belly), hepatomegaly and pitting oedema.
  • Dry, dark skin which splits where stretched over pressure areas to reveal pale areas.
• Nutritional dwarfism:
  • Patient is small for age.
  • Face shape may be affected by size of teeth.

Other clinical features may include:^[7]

• Fever related to systemic infection (especially Gram negative coliforms such as Escherichia coli and Klebsiella pneumoniae)
• Respiratory distress
• Heart failure
• Electrolyte abnormalities (hypophosphataemia, hypokalaemia, hypoglycaemia)
• Marked anorexia
• Anaemia
• Profuse diarrhoea
• Shock

Differential diagnosis

Elderly failure-to-thrive^[8] (weight loss >5% of baseline, decreased appetite, poor nutrition, inactivity) - consider in addition to malnutrition:

• Impaired physical function (for example, infection, malignancy, renal or heart failure)
• Depression
• Dementia

Severe malnutrition - may all co-exist:

• Dehydration
• Severe infection
• Hypoglycaemia
• Anaemia

Investigations

• Anthropometric assessment:^[7]
  • Height and weight (height and weight for age and weight for height are sensitive markers in childhood and a z score, comparing an individual child to a healthy reference population, can be derived, expressed in units of standard deviations from the mean of the reference population)
    • Moderate malnutrition is defined as a weight for height z score between 2 and 3 standard deviations (SD) below the mean.
    • Severe malnutrition is defined as the weight for height z score more than 3 SD below the mean.
  • BMI (used mainly in adults)
  • Mid upper arm diameter (overdiagnoses among younger children, undiagnoses among older children)
    • An upper arm circumference <110 mm is also used to define severe malnutrition in children.
    • Asian prospective studies have found that an upper arm circumference of <110 mm was the best single anthropometric predictor of death from malnutrition within 6 months.
  • Skin folds
  Note, standardised reference tables need to be appropriate for use with a particular ethnic group and may not be accurate for elderly populations.
• For the investigation of malnourished children in developing countries, WHO recommends:
  • Blood glucose
  • FBC and film
  • Urine MC&S
  • Stool OC&P
  • serum albumin
  • HIV test
  • U&Es
  Note, tuberculin skin testing is less reliable in the malnourished child.
  
  Additional tests to assess nutritional status may include:
  • Iron studies, folate, B12
  • Pre-albumin, transferrin, retinol-binding protein (better short-term indicators of protein status than albumin alone)
  • Thyroid function tests
  • Coeliac serology
  • Calcium, Phosphate, Zinc
  • Vitamin levels - if deficiency suspected
• Most accurate evidence of malnutrition in an elderly patient is hypocholesterolaemia and hypoalbuminaemia^[8]

Management

General measures for elderly population in UK

• General nutritional advice.
• Use of supplements - more effective than nutritional advice alone.^[9]
• Inability to shop/prepare meals - refer to social services, meals on wheels, community dietician, local day centres.
• Factors such as increasing number of people present at meals,^[10] improving the palatability of meals and finding optimal time of day and location of meals may also improve intake.
• Difficulty with feeding utensils - refer to occupational therapy to consider aids/equipment.
• Nausea - consider anti-emetics.
• Oral pathology - treat if present.
• Dysphagia - investigate and refer to speech and language therapy. If not amenable to treatment, consider pureed food or thickened fluids.

Acute management of severely malnourished^[6][7]

• Clinical assessment - check for co-existing dehydration, infection, anaemia, hypoglycaemia.
• Correct shock and dehydration and restore electrolyte balance. NICE guidelines state that electrolyte and fluid imbalances do not need to be corrected prior to feeding, but should be done alongside.^[1] Reverse malnutrition without overloading cardiac, renal, GI, or hepatic function.
• Care needs to be taken to avoid refeeding syndrome.^[11] Refeeding syndrome is the potentially fatal shifts in fluids and electrolytes that can occur in malnourished patients receiving artificial refeeding, whether parenteral or enteral. Biochemical features include:
  • Fluid-balance abnormalities
  • Abnormal glucose metabolism
  • Hypophosphataemia
  • Hypomagnesaemia
  • Hypokalaemia
  • Thiamine deficiency
  Patients at high risk of refeeding syndrome include those with:

  • Anorexia nervosa
  • Chronic alcoholism
  • Cancer
  • Postoperative debilitation
  • Elderly patients with comorbidities and decreased physiological reserve
  • Uncontrolled diabetes mellitus
  • Chronic malnutrition:
    • Marasmus
    • Prolonged fasting or low energy diet
    • Morbid obesity with profound weight loss
    • High stress patient unfed for >7 days
    • Malabsorptive syndrome (eg inflammatory bowel disease, chronic pancreatitis, cystic fibrosis, short bowel syndrome)
  • Long term use of antacids
  • Long term use of diuretics
  To prevent refeeding syndrome:^[1]
  • Refeeding should be started at no more than 50% of energy requirements in "patients who have eaten little or nothing for more than 5 days", with the rate increasing if no refeeding problems are detected on clinical and biochemical monitoring
  • For high risk patients, start nutritional repletion of energy should be started slowly (maximum 0.042 MJ/kg/24 hours), increasing to meet or exceed full needs over 4-7 days.
  • In patients who are very malnourished (BMI≤14 or a negligible intake for 2 weeks or more), refeeding should start at a maximum of 0.021 MJ/kg/24 hours, with cardiac monitoring owing to the risk of cardiac arrhythmias.
  • Oral, enteral, or intravenous supplements of the potassium, phosphate, calcium, and magnesium should be given unless blood levels are high before refeeding.
  • Check electrolyte levels once daily for one week, and at least three times in the following week.
• Any severely malnourished child with immediately life threatening complications should be stabilised and treated in an inpatient environment. Refeeding should start at 100 kcal/kg/day, every 2 hours and is usually with a milk based formula called F-75. Those with severe malnutrition without complications and who are able to accept and tolerate therapeutic food can be monitored in outpatients and treated in the community. They should be refed at 175 kcal/kg/day, usually with a therapeutic feed known as F-100.^[7]
• In children, there is often coexisting infection. This has such a high prevalence that WHO recommends use of empirical antibiotics for first 7 days.
• Vitamin supplementation should be started immediately, before and for the first 10 days of refeeding.^[1]
• Hypoglycaemia should be treated with IV glucose and/or oral sucrose.
• Cases showing hypothermia require warming.
• Rehabilitation phase of treatment: starts as child's appetite returns, usually a week after treatment is started. Many essential nutrients are still deficient. In the developing world, the use of fortified spreads (such as peanut butter carrying protein rich milk powder and micronutrient powders) have been used to treat acute moderate malnutrition in the community.
• Progress is monitored by regular weighing with weight gain target of 10-15g/kg/day. Return visits to outpatients can stop when anthropometry and clinical assessment show that the child has recovered.
• Identify causes and involve family/community in prevention of relapse.

Complications

• Slower wound healing
• Increased risk of infection
• Decreased muscle strength
• Poor cognition
• Increased dependency
• Increased mortality

Prognosis

Chronic malnutrition (particularly where associated with intrauterine growth retardation or early onset) leads to persistent growth retardation and cognitive deficit.^[12] Prognosis for PEM is worse with co-existent HIV infection.
Severe malnutrition in children carries a case fatality rate of 5-60%. Fatality rates for kwashiorkor are higher than those for marasmus.^[7]

Prevention

In adults (NICE guidelines)^[1]

Screening for malnutrition and for those at risk of developing it should take place:

• All hospital inpatients on admission and repeated on a weekly basis during admission.
• All outpatient attendees at first clinic appointment.
• On entering a care home.
• At initial registration with a GP and opportunistically at, for example, influenza vaccination.
• Where clinical concern exists.

Screening should assess BMI, percentage unintentional weight loss and consider time scale of reduced nutritional intake and likelihood of this continuing in the future. Tools such as MUST (Malnutrition Universal Screening Tool)^[13] exist to aid this assessment.

Options for nutritional support include the use of oral, enteral or parenteral nutrition alone or in combination.

GPs widely prescribe oral nutritional supplements, most often to those with cancer or cardiovascular disease, but rarely record height, weight or other markers of nutritional status prior to prescribing.^[14] There is evidence for the benefit of protein and energy supplementation in older people at risk of malnutrition, in particular, a reduction in mortality rate.^[15]

Using oral nutritional support:

• Use appropriate fortified standard foods as first-line treatment of malnourished patients prior to use of supplements.
• Always use in conjunction with appropriate dietary advice.
• Do not prescribe on a long-term basis without regular monitoring and reassessment.
• Nutritional needs and food intake determine the number of supplements needed - usually not more than 500-600 Kcal daily (approximately 2 cartons of sip feed) unless under care of a dietician.
• Supplements should be given between meals and not with or instead of a meal.
• Try different flavours and types of feeds to avoid boredom.
• Only prescribable on the NHS for ACBS (Advisory Committee on Borderline Substances) approved conditions (short bowel syndrome, malabsorption syndromes, pre-operative preparation of malnourished patients, inflammatory bowel disease, total gastrectomy,dysphagia, bowel fistulae, disease-related malnutrition).

Consider carefully consent issues and whether or not the provision/withdrawal of nutritional support is appropriate - GMC guidance is available.^[16]

In childhood

• Good prenatal nutrition - importance of pre-conceptual and antenatal care.
• Promotion of breastfeeding.
• Health promotion/education - regular age-appropriate nutritional advice and counselling during childhood.
• Specific programmes addressing micronutrient supplementation/fortification (eg Vitamin D, iodine) according to population needs.
• Improvement of hygiene and sanitation to reduce infectious disease and parasitic load.
• Global political and economic commitment to achieving UN millennium development goals - specifically: the reduction of levels of extreme poverty and hunger to half 1990 levels by 2015.