S1B5 - Nutrition: nutrition in disease

Question 1

What is the name for the condition that occurs when a person starts to eat again after a period of prolonged starvation?

Answer 1

refeeding syndrome

Question 2

After how many days of going without food should you be concerned about refeeding syndrome?

Answer 2

Refeeding syndrome can start in a person who has been without food for only five days.

Question 3

What happens to insulin secretion during starvation?

Answer 3

In starvation the secretion of insulin is decreased in response to a reduced intake of carbohydrates

Question 4

What happens to fat and protein stores during starvation?

Answer 4

• In starvation the secretion of insulin is decreased in response to a reduced intake of carbohydrates
• Instead fat and protein stores are catabolized to produce energy.

Question 5

What happens to intracellular electrolyte levels during starvation? What electrolyte in particular?

Answer 5

• In starvation the secretion of insulin is decreased in response to a reduced intake of carbohydrates
• Instead fat and protein stores are catabolized to produce energy.
• This results in an intracellular loss of electrolytes, in particular phosphate

Question 6

During starvation, what happens to serum phosphate concentrations?

Answer 6

Malnourished patients’ intracellular phosphate stores can be depleted despite normal serum phosphate concentrations.

Question 7

When a patient goes from starvation to feeding, what happens to insulin secretion?

Answer 7

When they start to feed a sudden shift from fat to carbohydrate metabolism occurs and secretion of insulin increases.

Question 8

What happens to phosphate electrolyte levels both in and out of the cells while going from starvation to feeding? What is the normal timeframe of this occuring?

Answer 8

• When they start to feed a sudden shift from fat to carbohydrate metabolism occurs and secretion of insulin increases.
• This stimulates cellular uptake of phosphate, which can lead to profound hypophosphatemia.
• This phenomenon usually occurs within four days of starting to feed again.

Question 9

Why is phosphate necessary?

Answer 9

Phosphate is necessary

• Generation of adenosine triphosphate
• Other crucial phosphorylation reactions

Question 10

Intravenous supplementation of what nutrient is required to prevent refeeding syndrome?

Answer 10

Intravenous phosphate is required as oral supplementation is inadequate.