INP midterm - LIVER

Question 1

What are the primary functions of the liver?

Answer 1

1) Bile – secretion and excretion
2) Infection – globulins and complement (fights infections)
3) Oncotic Pressure - makes albumin and transferrin
4) Lipid Metabolism – digests and absorbs lipids
5) Glucose Homeostasis – through glycogenesis, glycogenolysis, and gluconeogenesis
6) Coagulation – makes fibrinogen, clotting factors, and vitamin K
7) Detoxification – conjugation, degradation, NH3 & urea

Question 2

What are some of the reasons why a person with liver disease would be malnourished?

Answer 2

–> Decreased intake of nutrients

–> Early satiety

–> Increased losses of nutrients, minerals, vitamins

–> Malabsorption – fat, bile acid deficiency

–> Hypermetabolic state

Question 3

What are the nutrition considerations for patients with acute liver injury?

Answer 3

–> Catabolism exceed anabolism

–> Carbohydrates become preferred source of energy

–> Need adequate protein delivery to avoid muscle breakdown and as a substrate for gluconeogenesis

–> Favorable nitrogen balance

–> Early enteral nutrition reduced infectious complications

–> Meet full calorie need by no more than a week

Question 4

What are the nutrition considerations for patients with chronic liver disease?

Answer 4

–> Early parenteral nutrition may increase infection

–> Obese patient may trend towards lower calories and increased protein

–> Delayed clearance of NH3 from protein metabolism can exacerbate hepatic encephalopathy

–> Excessive fluids (liver senses low fluid and retains more solvent) – herniation

–> Parenteral nutrition additive toxicity to live

–> Protein needs 25-50% higher than baseline (bad – low branch chain to aromatic amino acid ratio)

Question 5

What are the nutritional recommendations given to patients with chronic liver disease?

Answer 5

–> Eat small and frequent meals to avoid fasting

–> Consume high complex carbs - 35-40 kcal/body kg/day

–> Consume BCAA enriched formulas

Question 6

What is nonalcoholic fatty liver disease (NAFLD)?

Answer 6

Macrovesicular fat in >5% of hepatocytes in the absence of: significant alcohol, drugs, toxins, viral hepatitis, TPN, metabolic errors, cystic fibrosis, Wilson’s Disease

Question 7

What is the clinical presentation of NAFLD?

Answer 7

–> MOST are asymptomatic

–> Insulin resistance (pre-diabetes)

–> Obesity

–> Hypertension

–> Dyslipidemia

–> accelerated atherosclerotic heart disease

Question 8

Describe the pathogenesis of NAFLD.

Answer 8

1) TG accumulation - excessive import of free FA but decreased hepatic export, and impaired B-oxidation
2) Insulin resistance - genetic basis unclear; potential polymorphisms in apoprotein C3, IL-6, adipose tissue, or alteration in peroxisome promoter
3) hepatocellular injury - ROS, defects in mito oxidative phosphorylation, activation of proinflammatory cytokines/mediators
4) Antioxidant depletion – impaired T reg function (glutathione, Vit E, b-carotene, Vit C)
5) Iron – insulin resistance and increased hepatic iron, HFE gene more prevalent, iron stores correlate with fibrosis severity, may generate ROS in iron reduction process
6) Leptin – decreased leptin production from adipose leads to obesity, may contribute to fibrosis, CNS effects

7) Adiponectin – beneficial adipose hormone
enhances plasma lipid clearance, FFA metabolism in muscle
suppresses TNF-alpha (anti-inflammatory effect)

8) Resistin – adipose-derived protein that leads to insulin resistance
9) Intestinal microbes – altered intestinal permeability, endogenous alcohol and acetaldehyde production, endotoxin production, deconjugation of bile salts

Question 9

How is NAFL(Non-alcoholic Fatty Liver)/NASH diagnosed?

Answer 9

–> Imaging (enlarged liver), labs (AST and ALT NASH has higher ALT, elevated ferritin, auto-immune markers)

–> Liver biopsy

Question 10

How is the severity of NAFL/NASH measured?

Answer 10

• -> Radiographic findings:
  * Sonogram – increased brightness
  * CT scan – decreased hepatic attenuation
  * MRI – increased fat signal
  * MR spectroscopy

Question 11

Summarize the treatment options for NAFLD. In particular, what dietary interventions have been shown to be beneficial?

Answer 11

• -> Lifestyle modification
• -> Drugs:
  * Vitamin E– decreases oxidative stress
  * Insulin sensitizing agents (thiazoldinediones, metformin)
  * Omega-3 fatty acids

Vitamin E has been found to be the most beneficial

Question 12

Who needs a liver transplant?

Answer 12

–> people with liver failure (loss of function)- coagulopathy, encephalopathy, cholestasis

–> cancer patients

• -> people with structural-related complications such as:
  * Ascites (excess free fluid)
  * Portal hypertensive bleeding
  * Hepatorenal syndrome
  * Hepatopulmonary syndrome

Question 13

What are the benefits of a living donor liver transplant?

Answer 13

–> Timing of procedure

–> No graft ischemia

–> Potential long term immunological advantages

–> Bonding experience

Question 14

What are some of the problems with a living donor liver transplant?

Answer 14

–> Small risk to donor

–> Reduced size graft

Question 15

What are the common complications affecting people with liver transplants?

Answer 15

–> Obesity (major one)

–> Hyperglycemia

–> Bone disease

–> Growth failure

–> Hyperlipidemia

–> Minimizing/eliminating steroids

–> Drinking