Nutrient Metabolism

Question 1

Causes of Mal digestion

Answer 1

Chronic pancreatitis, CF, pancreatic carcinoma

Question 2

Causes of Inadequate absorptive surface

Answer 2

Intestinal resection, gastro colic fistula, jejuno-ileal bypass

Question 3

Causes of bile salt deficiency

Answer 3

Cirrhosis, cholestasis, bacterial overgrowth, impaired ileal reabsorption, bile salt binders

Question 4

Causes of lymphatic obstruction

Answer 4

Lymphoma, Whipple’s disease, intestinal lymphangiectasia

Question 5

Causes of vascular disease

Answer 5

Constructive pericarditis, right sided heart failure, mesenteric arterial or venous insufficiency

Question 6

Causes of Mucosal disease

Answer 6

Infection (giardia, Whipple’s disease, tropical sprue, Inflammatory diseases, radiation enteritis, eosinophilic enteritis, ulcerative jejunitis

Question 7

Energy balance in health

Answer 7

Carbs fats and proteins should balance out: Basal metabolism (size, sex and age); Thermic effect of food (TEF) (digestion, absorption and utilisation); Thermogenesis (heat generated)
In health glucose is the primary fuel for energy – metabolism and citric acid cycle
Fat and proteins are conserved

Question 8

Energy balance in disease

Answer 8

In absence of food glucose maintained through mobilisation of glycogen stores and if prolonged gluconeogenesis, lipolusis
In disease inflammatory response – cytokines: TNF-alpha – insulin resistance, glycolysis; IL2 – glucose metabolism; IL4 lipid and glucose metabolism; IL6 lipolysis
Activity and appetite reduced (due to effects on thermic effect of food, thermogenesis and physical activity)
BMR increases

Question 9

Acute Illness and Growth Hormone

Answer 9

Critical illness causes an increase in the synthesis of growth hormone (negative feedback)
Anti insulin effects
Anti-anabolic effects (decreased skeletal muscle hypertrophy and disinhibition of protein catabolism)
Decreased insulin sensitivity
Increased lipolysis
Increased glycogenolysis
Decreased glycogen synthesis
Increased protein catabolism
Decreased protein synthesis
Clinical manifestations: hyperglycaemia, hyperlipidaemia, hypercatabolic state, muscle wasting

Question 10

Risk factors for refeeding syndrome

Answer 10

BMI <16kg/m2
Unintentional weight loss greater than 15%
little or no nutritional intake for more than 10 days
low levels of K, phos, Mg
History of alcohol abuse/drugs inc insulin, chemo or diuretics

Question 11

Chronic illness

Answer 11

Start with food
Focus on balanced diet
Diet to increase energy intake 
Diet to reduce work of kidney and inflammation
Diet to support treatment

Question 12

Acute illness

Answer 12

Start with food but consider other routes such as enteral parenteral
Diet to meet energy demand and reduce catabolism
Diet to support recovery - micro and macronutrients