Nutrition Disorders: Malabsorption

Question 1

What is malabsorption?

Answer 1

• a disorder that occurs when people are unable to absorb nutrients from their diets
• this can contribute to clinical outcomes

Question 2

Does malabsorption take place predominantly with macro or micro nutrients?

Answer 2

• can be both
• can be one specific macro or micro nutrient or everything

Question 3

What part fo the GIT does the majority of absorption take place?

Answer 3

• small intesintes
• duodenum, jejunem and ileum

Question 4

Is malabsorption long or short term?

Answer 4

• can be both
• short term = coeliacs flair up
• long term = bowel resection

Question 5

Where in the pancreas do endocrine secretions come from?

Answer 5

• islets of langerhans (generally in tail of pancreas)
• insulin and glucagon secreted directly into blood

Question 6

Where in the pancreas do exocrine secretions come from?

Answer 6

• acinar cells (generally in the head of the pancreas)
• pancreatic enzymes and juice are secreted

Question 7

Malabsorption can be caused by a number of factors. Alterations to secretions in the GIT is one of these, what can happen if enzyme secretions into the GIT are low?

Answer 7

• low enzyme secretion
• a-amylase = low carbohydrates digestion
• pancreatic lipase = low fat digestion
• proteolytic enzymes = low protein digestion

Question 8

Malabsorption can be caused by a number of factors. Alterations to secretions in the GIT is one of these, what can happen if there are intraluminal (GIT fluid secretions) factors?

Answer 8

• low gastric or pancreartic juice secreted
• enzymes work at specific pHs
• high pH in duodenum due to low acid called achlorhydria
• low pH in duodenum causing Zollinger - Ellinson syndrome.

Question 9

Malabsorption can be caused by a number of factors. Alterations to secretions in the GIT is one of these, what can happen if there are bile salt deficiencies causes by liver disease?

Answer 9

• lack of fat digestion

Question 10

What are the 4 main causes of malabsorption?

Answer 10

1 - alterations to gastric secretions.

2 - alterations in gastric structure/absorptive capacity.

3 - alteration in gastric motility.

4 - reduction in blood flow

Question 11

What is autosomal recessive disease?

Answer 11

• autosomal = non sex chromosomes
• 2 copies of abnormal gene are required to cause disease

Question 12

Cystic fibrosis is an autosomal recessive disease. What can this do to the GIT?

Answer 12

• blockage of ducts of pancreas due primarily to low Cl-
• can then cause high Na+ and H2O in cells
• causes thick pancreatic juice that blocks pancreatic ducts

Question 13

In a patient with cystic fibrosis, what are some of the nutritional considerations?

Answer 13

• low energy intake
• impaired nutrient absorption (fat, proteins and carbs)
• low fat soluble vitamin absorption (ADEK)

Question 14

How can bowel resection contribute towards malabsorption?

Answer 14

• reduced absorbative capcity
• reduced secretions into the GIT

Question 15

How can bowel inflammation contribute towards malabsorption?

Answer 15

• GIT walls are damaged and inflammed (IBS and pancreatitis)
• secretions and absorption are low

Question 16

What is coeliac disease?

Answer 16

• immune system disease
• immune system attacks GIT wall when gluten is eaten
• malabsorption can occur

Question 17

In coeliac disease the GIT walls are damaged when the immune system attacks the walls when gluten is eaten? What does this do this do to the villi and cause as a secondary effect?

Answer 17

• causes villous atrophy
• nutrients can not be absorbed

Question 18

Coeliac disease is an auto immune disease that damages the GIT, specifically causing villous atrophy. How can this be treated?

Answer 18

• remove gluten from the diet

Question 19

In coeliac disease which mineral is specifically important to monitor?

Answer 19

• calcium

Question 20

What is inflammatory bowel disease (IBD), and what are the 2 main diseases of IBD?

Answer 20

• chronic inflammation of the GIT
• crohn’s disease and ulcerative colitis

Question 21

Inflammatory bowel disease is a chronic condition characterised by inflammation of the mucosal surface. What are the common symptoms of IBD?

Answer 21

• reduced quality of life
• abdominal pain, diarrhoea with and without blood and mucus
• urgency and tenesmus (needing to go but no stool)
• weight loss
• fatigue

Question 22

In inflammatory bowel disease they are often advised to take a routine multivitamin, why is this?

Answer 22

• vitamin and mineral deficiencies are common
• minerals iron, zinc, copper, beta carotene and folate
• vitamins B12, B6, E,C,D

Question 23

In inflammatory bowel disease parts of the inflammaed bowel can be removed. If an ileal resection or bacterial overgrowth occurs in Crohns disease, what vitamin and nutrient deficiency can this cause?

Answer 23

• B12 and lactase deficiency

Question 24

In inflammatory bowel disease osteoperosis is common, why?

Answer 24

• low calcium absorption
• low activity levels due disease

Question 25

Microcytic anaemia is caused by iron deficiency. This can be caused by a low intake, but is more likely to be due to malabsorption. How can inflammatory bowel disease contribute to microcytic anaemia and normacytic anaemia?

Answer 25

- microcytic anaemia = inflammed GIT causing low absorption - normocytic anaemia = chronic internal blood loss

Question 26

Gastric ressection can be performed for a number of reasons. What are the most common impairments that may occur?

Answer 26

- impaired motility - reduced secretion of a intrinsic factor, enzymes and HCl - rapid gastric emptying ('dumping')

Question 27

What is intestinal failure?

Answer 27

- term used to describe a variety of diseases or injuries to the small intestine that can result in surgery and resections - impair ability to absorb adequate nutrients and water - patients eat but do not absorb causing malnourisment and dehydration

Question 28

If a patient has a large bowel resection, which is responsible for the reabsorption of H2O and electrolytes, what can happen?

Answer 28

- diarrhoea as H2O is not absorbed - vitamin B12 and biles acids can be affected

Question 29

If a patient has a large bowel resection, this can reduce the reabsorption of H2O and electrolytes. Is this permanent or can the body adapt?

Answer 29

- 6-8 weeks following surgery ileum appears to adapt and losses decrease but still remain at ~400-600mls per day

Question 30

What is dumping syndrome?

Answer 30

- impaired gastric motility - symptoms where food leaves the stomach too quickly

Question 31

Dumping syndrome is a symptom where food leaves th stomach too quickly and enters the duodenum. What can this cause in the duodenum?

Answer 31

- chyme is not adequately prepared to allow efficient absorption - malabsorption of fluids and nutients occurs

Question 32

Dumping syndrome can be classified as early or late dumping, what are these?

Answer 32

1 - early dumping = occurs soon after eating - causes sweating, dizziness, faintness, rapid weak pulse and hypotension 2 - late dumping = prolonged - causes weakness, cold, faintness and sweating ~2 hours after a meal

Question 33

How can impaired blood flow cause malabsorption?

Answer 33

- impaired transport mechanisms - impaired fat transport e.g. congenital lymphangiectasia. - impaired monosaccharide transport e.g. congenital primary malabsorption of glucose and galactose - vascular disease

Question 34

If pancreatic disease is present, for whatever cause, what can happen to a patient?

Answer 34

- endocrine insufficiency - exocrine insufficiency (fats and vitamin D are big concerns)

Question 35

Pancreatic disease can cause exocrine insufficiency. Patients are prescribed enzymes such as creon, when mjust these prescriptions be taken?

Answer 35

- with meals

Question 36

What are the key diagnostic criteria that can all be used or used in isolation for malabsorption?

Answer 36

**- diarrhoea or change in stool consistency (MAIN ONE)** **- abdominal distension (MAIN ONE)** **- fatulence or wind (MAIN ONE)** - loss of weight in adults or growth failure in children - hypoproteinaemia (low serum albumin / prealbumin) - iron deficiency anaemia or low serum ferritin

Question 37

What is steatorrhea?

Answer 37

- increased fat content in stools - a clinical features of fat malabsorption - also common in exocrine pancreatic insufficiency (EPI), celiac disease, and tropical sprue

Question 38

Why can fat malabsorption be a big cause of energy intake?

Answer 38

- fats have highest calories/gram so big loss in energy intake

Question 39

How can fat malabsorption be accentuated by low fat products?

Answer 39

- patients are scared of having steatorrhea - they swithc to low fat products to avoid this - this further accentuates fat malabsorption

Question 40

In patients with fat malabsorption what are treatment options?

Answer 40

- increase calorie intake - multivitamin supplement (specifically fat soluble)

Question 41

What is the most common cause of carbohydrate malabsorption?

Answer 41

- lactose malabsorption - patients may lack the lactase enzyme - unable to digest lactose into galactose and glucose

Question 42

What carbohydrate malabsorption, specifically lactase deficiency cause?

Answer 42

- lactose remains in the GIT causing osmotic diarrhoea. - bacteria ferment lactose resulting in symptoms such as abdominal distension, flatulence and explosive watery diarrhoea

Question 43

There are a lot of common nutritional deficiencies in the UK that results from malabsorption. What are 2 of the most common causes of malabsorption?

Answer 43

1 - disease of the GIT 2 - ressection of the GIT - both cause can chronic diarrhoea and / or self imposed dietary restriction

Question 44

There are a lot of common nutritional deficiencies in the UK that results from malabsorption. What are older and young children specifically at risk of following acute episodes of diarrhoea?

Answer 44

- dehydration with loss of fluid and electrolytes

Question 45

There are a lot of common nutritional deficiencies in the UK that results from malabsorption. What patients with alcoholic liver disease specifically at risk of?

Answer 45

– thiamine (B1) deficiency - vitamin D deficiency

Question 46

There are a lot of common nutritional deficiencies in the UK that results from malabsorption. What are patients with inflammatory bowel disease specifically at risk of?

Answer 46

- iron, B12, vitamin D, vitamin K, folic acid, selenium, zinc, vitamin B6, and vitamin B1 deficiencies