Lecture 13 - Malabsorption Conditions Flashcards
What is malabsorption?
Inadequate absorption of nutrients from the GI tract
Where does most absorption happen?
through the small intestine
What happens when food gets to the stomach?
it is mixed and digestive processes start
What happens once food reaches the duodenum?
more digestive enzymes are added, the food is broken down and absorbed into the body in the small intestine
What are macronutrients?
main food groups
carbohydrate, fat, protein
What are micronutrients?
key to our general health and wellbeing
vitamins and minerals
What are the types of malabsorption?
acute vs chronic
What are examples of mucosal (absorption) problems?
Crohn’s disease
coeliac
surgery
What is mucosal absorption deficiencies?
where the mucosa within the small intestine isn’t working properly
What are pre-mucosal issues related to?
digestion and digestive tissues
What are examples of pre-mucosal (digestion) problems?
pancreatitis
cystic fibrosis
lactase deficiency
What is pancreatitis?
the pancreas is not producing enough pancreatic enzymes added in the duodenum
What does lactase deficiency effect?
the ability to break down lactose and other carbohydrates
What effect do Crohn’s and coeliac have?
Mucosal
abnormal epithelium (epithelial cells do not develop properly) = deficient absorption
What effect do surgical resection, bypass and congenital abnormality have?
Mucosal
shorter bowel means less surface area for absorption, can be temporary or permanent
What effect do cystic fibrosis and pancreatitis have?
Pre-mucosal
insufficient digestive agents, so food is not broken down allowing it to be absorbed
What is small intestinal bacteria overgrowth?
Both
damage to mucosa +/- bile salts metabolised by bacteria
affects mucosal ability to absorb food
What does crohn’s disease cause?
malabsorption linked to inflammation (+/- surgical resection)
Consequences of Crohn’s disease?
iron deficiency anaemia
B12/folate deficiency
vitamin D and calcium deficiency (osteoporosis/osteomalacia)
What does steroid use in IBD effect?
bones
What can vitamin D and calcium deficiency affect?
bone development and lead to osteoporosis or rickets in children
can be treated with supplementation
What is coeliac disease?
mucosal
an autoimmune condition, gluten activates an abnormal mucosal response which causes chronic inflammation and damage - villous atrophy
this causes poor absorption of food
Symptoms of coeliac?
fatigue, GI symptoms, weight loss
how is coeliac diagnosed?
via serological testing
Common complications of coeliac?
anaemia, osteoporosis (vit D&calcium)
Treatment of coeliac?
elimination of gluten from the diet
What is short bowel syndome?
MUCOSAL
usually secondary to surgery. can be congenital
removing a chunk of the small intestine, affects the ability to absorb food
What might short bowel syndrome require?
parenteral nutrition, depending on how much has been removed
Complications of short bowel syndrome?
osteoporosis and vitamin deficiencies
How can the vitamin deficiencies and osteoporosis be treated?
supplementation of calcium +/- vitamins and minerals
What do we need to be aware of in short bowel syndrome?
medications absorbed in the small intestine e.g. levothyroxine, warfarin, oral contraceptives, digoxin
What may be required with medications absorbed in the small intestine?
higher doses
How is parenteral nutrition administered in patients with short bowel syndrome?
through a tube via their blood vessels
What is chronic pancreatitis?
PRE-MUCOSAL
chronic inflammation leads to impaired function, lack of pancreatic digestive enzymes so food is not broken down properly
Who does chronic pancreatitis affect more?
men more than women
What is chronic pancreatitis associated with?
long term alcohol consumption
How is chronic pancreatitis diagnosed?
tests include faecal elastase (available tests only confirm severe pancreatic insufficiency)
also test for fat soluble vitamin deficiencies
What is cystic fibrosis?
it is inherited
decreased chloride secretion so increased sodium absorption = thick mucus in the lining
What does cystic fibrosis affect?
pancreatic function and causes pancreatic insufficiency in ~85% of patients
What does cystic fibrosis cause?
steatorrhoea (faeces and yellow and floaty)
osteoporosis - multi factorial
malnutrition (from poor absorption of nutrients)
weight loss
What is the treatment for cystic fibrosis?
pancreatic enzyme supplementation, fat soluble vitamin supplementation, calorie replacement
What else do we check for in cystic fibrosis?
intestinal obstruction
What is lactase deficiency?
PRE-MUCOSAL
primary, secondary or congenital or developmental
Treatment for lactase deficiency?
reduce or eliminate dietary lactose intake
What may be required in patients with lactase deficiency?
alternative calcium source due to reduced intake of dairy
Why is lactase deficiency tested for in babies?
it is frequently missed and can cause severe repercussions e.g. brain and development issues
What does bacterial overgrowth affect?
both mucosal and digestive processes
When does bacterial overgrowth incidence increaase?
with age
What is bacterial overgrowth affected by?
chronic pancreatitis and motility disorders
What can impaired motility be caused by?
diabetes, radiation enteritis, drugs, post surgery (loops)
What else can affect bacterial overgrowth?
reduced gastric acid - atrophic gastritis, drugs
What is fat malabsorption?
problem with digestion (insufficient enzymes, bile) or absorption
When is malabsorption more common?
in coeliac, crohn’s disease
What does fat malabsorption cause?
deficiencies of fat soluble vitamins (A,D,E,K)
What are fat soluble vitamins necessary for?
a variety of bodily functions and need to be absorbed in the fats we take in
What is a symptom of fat malabsorption?
steatorrhoea - excess fat is lost in the stools, making them float and appear pale and bulky and smell offensive
What does poor fat absorption affect?
the absorption of vitamins A,D,E,K
What can vitamin malabsorption cause?
vitamin D deficiences such as osteomalacia (rickets), osteoporosis
What does a lack of vitamin D cause?
bone matrix does not form properly, bones are thinner, brittle and more likely to break
What does a lack of vitamin K cause?
clotting problems, makes you more prone to bleeding
Treatment options for carb, protein and fat malabsorption?
supplementation of pancreatic enzymes - lipase, amylase and protease (Creon)
in pancreatitis, CF where there are deficiencies of pancreatic enzymes
What does supplementation of pancreatic enzymes cause?
reduces steatorrhoea, boosts nutritional status by allowing food to be broken down and absorbed
What does creon capsules cause?
local irritation
When should creon capsules be taken?
during or just after a meal
Strengths of creon capsules?
10,000 units and 25,000 units
What is important about creon capsules?
they are derived from pork - religious issues and allergies
What causes iron malabsorption?
impaired absorption - mucosal absorption is not working properly and iron isn’t absorbed
When is iron deficiency anaemia commonly seen?
in patients with coeliac, crohn’s, small bowel resection
When is there a potential blood loss?
in crohn’s and ulcerative colitis
Treatment of iron malabsorption?
oral iron replacement
Why is oral iron replacement problematic?
absorbing iron can be difficult, it reaches a plateau and it doesnt matter how much you take over and above this but can get complications from too much iron
When was the gluten free foods service introduced?
in scotland in 2014/15
who gets the gluten free food service?
patients with a diagnosis of coeliac or dermatitis herpetiformis
How many units per months of gluten free food can a patient get?
~14
it is providing basic food without providing luxuries
What else needs to be considered with intolerances?
lactose and gluten in medicines
What is an issue with malabsorption?
need to consider where drug will be absorbed
How is gluten found in medicines?
as wheat starch used as a bulking agent
sign of fat malabsorption?
steatorrhoea
sign of protein malabsorption?
muscle wasting, malnutrition, oedema
sign of carb malabsorption?
bloating, flatulence, diarrhoea
sign of vit D/calcium malabsorption?
bone problems
Vit E malabsorption?
neurological problems
Vit K malabsorption?
coagulation (bleeding) problems
Vit A malabsorption?
night blindness
