12) Adulthood and the Elderly (Part II) Flashcards
When does the number of functional taste buds decrease?
60 years of age
What are the consequences of a decrease in the number of functional taste buds?
- Decreases the capacity to taste and smell
- Reduces appetite
- Decreases palatability
- Decreases food intake
- Prescribed diets are low in taste
What are the components of saliva?
- Water
- Electrolytes
- Mucus
- Glycoprotein enzymes
- Anti-bacterial compounds (IgA, lysozyme)
What are the three primary functions of saliva?
1) Initiates the process of digestion of dietary starches and fats
2) Play a role in protection against dental caries
3) Lubricates food, allowing for the initiation of swallowing
What is xerostomia?
Dry-mouth
Xerostomia is present in 20% of the elderly. What are possible causes? (2)
- Drug intake (anti-hypertensives, anti-depressants, bronchodilators)
- Disease (e.g. autoimmune disease)
What are the effects of a decrease in salivary secretion?
Increases the risk of infections and ulcers
What is the effect of a decreased ability to swallow (dysphagia) due to a decreased salivary secretion?
May result in a decreased food intake
What is a likely consequence of a decrease in esophageal function?
Dysphagia
What are causes of dysphagia? (3)
- CNS changes
- Diabetic neuropathy
- Parkinson’s disease
An individual is prone to dysphagia if there is impaired __________ function.
esophageal
Choking increases the risk of which disease? Why?
- Pneumonia
- Food may be aspirated into the lungs
- Choking is one of the leading causes of death among the elderly population
What are the primary functions of gastric acid?
- Acts as a chemical barrier against pathogenic colonization
- Facilitates food digestion
What does the stomach lining contain to protect from gastric acid? What occurs if these mechanisms fail?
- A layer of thick mucus containing sodium bicarbonate
- Heartburn or peptic ulcers may develop
Which gastric functions are impaired due to aging?
- Decrease in gastric acid production
- Decrease in parietal cell mass
- Decrease in the maintenance of commensal flora bacteria
What are the effects of a decrease in pepsin due to aging?
- Decreases proteolysis
- Results in a decreased vitamin B12 exposure to intrinsic factor
- Decreased absorption of vitamin B12
What are the effects of hypochlorhydria due to aging?
- Increase in pH in the proximal small intestine
- Causes bacterial overgrowth of the small GI (streptococci, lactobacilli)
What is the effect of bacterial overgrowth of the small GI?
These bacteria compete for B-vitamins, which decreases optimal nutrient availability
Dyspepsia increases the risk of ______.
ulcers
What are the functions of the liver?
- Glycogen storage
- Decomposition of RBCs
- Plasma protein synthesis
- Hormone production
- Detoxification
Why is the elderly highly susceptible to drug-related toxicity?
The liver no longer has the capacity to metabolize compounds properly due to a reduced production of drug-metabolizing enzymes
What are the effects of a decrease in bile production with age?
- Increases food intolerance (fatty foods)
- Increases GI distress, causing gas, nausea, vomiting and diarrhea
What are the effects of a decrease in the functioning sections of the pancreas with age?
A decrease in digestive enzyme production and nutrient absorption in the small intestine may occur with age, particularly if there is an underlying chronic disease
What are causes of an increased risk of constipation in the elderly?
- Low-fiber intake due to food intolerance
- Difficulty consuming fibrous foods
What are the effects of diverticulosis?
- Discomfort
- Diarrhea
- Constipation
- May lead to diverticulosis (bleeding and bowel obstruction)
Which nutrient deficiencies are related to lactose intolerance?
- Vitamin A
- Vitamin D
- Vitamin B2
- Protein
What are functions of the kidney?
- Regulation of electrolytes
- Maintaining acid/base balance
- Regulating blood pressure
The renal mass decreases by 30% by __ years of age.
90
What are the effects of a decrease in renal mass?
1) Decreases renal function
2) Decreases the capacity to excrete waste products from diets with a high intake of protein or electrolytes
What are the effects of glomerulonephritis?
Difficulties in the excretion of drugs and vitamins when taken in excess
Which nutrient deficiencies are related to a decrease in renal function? Why?
- Vitamin D because the kidneys are responsible for its bioactivation
- Water, glucose and amino acids, which are excreted instead of absorbed
How does the decline in renal function affect thirst mechanisms?
Increases the risk of dehydration, which is further exacerbated by the heavy use of diuretics and laxatives
What is the effect of the decrease in function of the liver AND kidney?
- Accumulation of drug metabolites
- May trigger a type III hypersensitivity response
What occurs during a type III hypersensitivity response?
- IgG and complement components attempt to bind to metabolites, forming immune complexes, which become subject of complement deposition, opsonization and phagocytosis
- Glomerulonephritis may occur as a response
About __% of individuals that are greater than 75 years of age meet the criteria for chronic kidney disease.
50
What are the five ways anti-vitamin drugs may block the actions of vitamins? (5)
1) Inhibiting their absorption
2) Binding to them (making them unavailable)
3) Enhancing their catabolism
4) Enhancing their excretion
5) Causing an inhibition of their activation in the body to an active form
What is polypharmacy a strong predictor for?
Malnutrition
Why is polypharmacy a strong predictor for malnutrition in the elderly?
- With increasing age, the body’s ability to metabolize drugs decreases
- The elderly is normally prescribed multiple medications
What are the four mechanisms by which drugs undergo movement in the body?
- Absorption
- Distribution
- Metabolism
- Excretion
What are possible effects of low serum albumin concentration on drugs?
May increase the availability of drugs and potentiate their effects
Where does drug metabolism normally occur? What is it facilitated by? What normally occurs?
- Liver
- Cytochrome P-450
- Conversion of fat-soluble compounds to water-soluble compounds
What are the effects of grapefruit on drug metabolism? What is the mechanism by which this occurs?
- Inhibit intestinal metabolism (by inhibiting cytochrome P-450) of numerous drugs
- Enhances their effects and risks of toxicity
Why have hospitals and healthcare centers removed grapefruit from their menu?
- Grapefruit enhances the risk of toxicity of certain drugs
- The effects may persist for 72 hours
What are the effects of monoamine oxidase inhibitors on nutrient metabolism?
- Prevent the breakdown of pressor agents in food (substances that increase BP)
- May cause a hypertensive crisis
What are the effects of vitamin K on Warfarin?
Vitamin K allows for the production of more clotting factors, making Warfarin less effective
What are the effects of Methotrexate and pyrimethamine on nutrient metabolism?
Folic acid antagonists
How may folic acid deficiency be prevented in individuals consuming folic acid antagonists?
- Consumption of greater folic acid
- Consumption of folinic acid (reduced form of folic acid), which does not require conversion to the active form
What drug may increase the risk of GI bleeding if ingested with alcohol?
NSAIDs
Define a drug-nutrient interaction.
The result of action between a drug and a nutrient that would not happen with the nutrient or the drug alone