Cystic fibrosis

Question 1

What is cystic fibrosis?

Answer 1

Cystic fibrosis is an inherited condition (autosomal recessive) caused by a defective genewhich codes for the CF transmembrane regulator protein, CFTP. Mutation of the CFTP gene prevents passage of chloride cells through the cell membrane causing the lungs and digestive system to produce abnormally thick and sticky mucus. Mucus builds up increasingly damaging the lungs affecting breathing in addition to digestion.

Question 2

What is the global prevalence of cystic fibrosis? WHat percentage of people have been diagnosed?

Answer 2

According to (Guo, 2022), the worldwide prevalence was an estimated 170,000 people.
65% are diagnosed

Question 3

What is the main nutritional complication of cystic fibrosis? What is the main cause of death following this complication?

Answer 3

Diabetes
Pulmonary disease.

Question 4

What are some nutritional management strategies for cystic fibrosis? (9)

Answer 4

1. High energy intake needed - continually assess energy requirements
2. High fat intake recommended
3. No restriction on protein or salt (dietary assessment)
4. Flexible meal plans
5. Strict adhesion to PERT
6. Enteral nutrition (if dieatry goals and supplements fail)
7. Pancreatic enzyme therapy
8. Vitamin supplementation (fat soluable ADEK)
9. Mineral supplementation (iron, zinc, selenium)

Question 5

What is the UK prevalence of cystic fibrosis?

Answer 5

Roughly 10,800 people in the UK have been diagnosed with CF (cystic fibrosis trust, 2023)

Question 6

Diffusion of what ions occurs in CF causing the sticky thick mucus due to dehydration?

Answer 6

Chloride ions

Question 7

Where are clinicial features of CF most commonly seen in the body?

Answer 7

Liver, pancreas, lung, intestines and vas defrens

Question 8

What are some clinical features of CF? (not nutritional) (respiratory and gastrointestinal) (10)

Answer 8

1. Infection and inflammation in the lungs
2. Increased energy demands
3. Coughing
4. Pancreatic insufficiency (PI) (>95% of pancreatic function capacity lost)
5. Pancreatitis
6. Meconium Ileus
7. Distal Intestinal Obstruction syndrome (DIOS) (usually following inadequate PERT)
8. Fibrosing colonopathy
9. Liver disease
10. Gastro-oesophageal reflux (GOR)

Question 9

*Pancreatic insufficiency reduces the secretion of bile causing malabsorption of fats and fat soluable vitamins

Answer 9

n/a

Question 10

WHat is the UK prevalence of CF?

Answer 10

Estimated 10,800 people in the UK (1 in every 2500) (Cystic Fibrosis Trust, 2023)

Question 11

WHat is the most common CF gene mutation seen in the UK?

Answer 11

F508del mutation

Question 12

What are some tests used to detect PI?

Answer 12

Indirect:
- Fecal fat analysis
- ELISA

Direct:
- ePFT

Question 13

What is the typical treatment for PI? What are the 3 types?

Answer 13

Pacreatic enzyme replacement therapy (PERT)
enteric-coated, non-enteric coated and lipase enzyme cartridge

Question 14

How does cystic fibrosis contribute to malnutrition? What unusual rule is given to CF individuals about fat intake?

Answer 14

Many CF sufferers have increased energy demands but fail to keep themselves in a positive energy balance. Reasonings are increased coughing, energy losses through sputum, PI.
Consume a diet with no fat restriciton.

Question 15

Even with maximised PERT, roughly how much ingested energy will not be absorbed?

Answer 15

10%

Question 16

What are some nutritional features of CF?

Answer 16

1. CF-related diabetes
2. CF-related osteoperosis
3. Increased energy requirement
4. Poor appetite
5. Iron deficiency anaemia
6. Fertility issues