Ger 2 Nutrition Flashcards
What pathological factors can have adverse effects on intestine?
Diabetes, pancreatitis, liver disease/malignancy
What can selective neurodegeneration of enteric nervous system lead to?
Dysphagia, GI reflux, and constipation
What is seen in rodents that suggest diet may influence the gut?
Caloric reduction in rodents can prevent neuronal loss
What can esophageal motility do?
Reduce the reduction of neurons in the mesenteric plexus in older people
Is the small intestine affected with changes in gastric motility as we age?
No… gastric motility is impaired with age, but the small intestine isn’t affected
What can be influenced by signal transduction pathways and cellular mechanisms that control smooth muscle function?
Colonic motility
What can influences in colonic motility lead to?
Constipation
Does gastric acid increase or decrease with age?
Decreases with age
Why does gastric acid reduce with age?
- Chronic gastritis
- Prolonged use of PPI
- Procedures such as vagotomy and gastric resections (which are seen more frequently in older population)
What does acid reduction predispose the gut to?
Small bowel bacterial overgrowth
In one of the studies presented, what % of patients on the geriatric ward had bacterial overgrowth of the small bowel and what % were malnourished
71% with bacterial overgrwoth
11% malnourished
What is bacterial overgrowth associated with?
Reduced body weight and reduced intake of micronutrients
What is a fluorescein dilaurate test?
It is a noninvasive test of exocrine pancreatic function
What is seen in the pancreas with age?
It shows structural changes, but no functional changes are seen (with the fluorescein dilaurate test)
Concentrations of what 3 things in pancreatic juice are shown to decline with age?
- Secretagogue-stimulated lipase
- Chymotrypsin
- Bicarbonate
What happens to the liver as we age?
It declines in size and blood flow, but microscopic changes are subtle
In aged mice, what were changes in expression of genes in liver involved in?
Inflammation, cellular stress, and fibrosis
What helped to reverse age-related changes seen in the liver?
Caloric restriction
What kind of changes occur in the small intestine as we age?
- Decline in number of villi and crypts
- Loss of villi and enterocyte height
- Declines in mucosal surface
What is the association between intestinal morphology and nutrient uptake with age?
No clear association
What is anorexia of aging?
Physiological change resulting with appetite and food consumption declining
What % does the average daily intake of food decrease by between 20 and 80 year olds?
Up to 30%
What is most of age-related decrease in energy a response to?
Decline in energy expenditure
What leads to weight loss in many older people?
When the decrease in intake is greater than the decrease in expenditure
When do body weight and BMI stop increasing?
Approximately 50-60 … they increase with age until this point, then start to decline
What did the 2 year prospective study show was the average weight loss in community-dwelling American men 65+?
- 5% body weight per year
13. 1% of thehgroup had weight loss of 4% per year
In the prospective CV health study looking at home-dwelling subjects over 65 who didn’t have cancer, what % had lost 5% or more of body weight after 3 years in the study?
17%
-This group was shown to have increased risk-adjusted mortality over the next 4 years compared to the group with stable weight
What does J shaped curve association with mortality and body weight mean?
There is increased mortality with low and high BMIs
At what BMI is there a steady increase in mortality?
Under 22
What is the combined effect of being underweight and increasing age?
Deleterious effects on mortality
What happens to body and and fat-free mass as one ages?
- Body fat increases
- Fat-free mass decreases (because of a loss of skeletal muscle
How many kg of lean body mass is lost per decade after age 50?
Up to 3kg
What is mean body fat of a 20 year old man weighting 80kg?
What is mean body fat of a 75 year old man weighing 80jg?
15%
29%
What is the cause of increased fat?
It is multifactorial:
- Reduced physical activity
- Reduced growth hormone sectretion
- Diminished sex hormones
- Decreased resting metabolic rate
How does the distribution of fat change as we age?
There is a greater proportion intra-hepatic and intra-abdominal
What is more intra-hepatic and intra-abdominal fast associated with?
Insulin resistance and higher risk of ischemic heart disease, stroke, and diabetes
What are 3 etiologies of weight loss?
- Wasting
- Cachexia
- Sarcopenia
What is wasting?
Involuntary loss of WEIGHT, mainly due to poor dietary food intake which can be caused by disease and psychological factors causing overall negative energy balance
What is cachexia?
Involuntary loss of fat-free mass (muscle, organ, tissue, skin, bone) or body cell mass
What causes cachexia?
Catabolism…this results in changes in body consumption
What else is seen in cachexia?
Acute immune response occurs
What cytokines are released in cachexia that have profound effects on hormone production and metabolism causing increased resting energy expenditure?
IL-1
IL-6
TNF-alpha
What 3 things causes negative nitrogen balance leading to loss of muscle mass seen in cachexia?
- Amino acids from muscle to liver
- Increase in gluconeogenesis
- Shift of albumin production to acute phase proteins
What conditions is cachexia seen in?
- Heart failure
- RA
- Malignancy
What is sarcopenia?
Decline in skeletal muscle mass (this is a major age-related physiological change in older people
What is the path of sarcopenia?
Reduced physical activity –> Muscle disease –> Muscle loss
What other things can cause saropenia besides lack of exercise?
Hormonal, neural, and cytokine activities play a role
How does increased cytokine activity contribute to sarcopenia?
It increases levels of acute phase proteins which break down muscle
How do hormones contribute to sarcopenia?
Declined levels of sex hormones, glucocorticoids, and catecholamines result in increased pro-inflammatory cytokines, which cause increased levels of acute phase proteins which break down muscle
How to neural changes impact sarcopenia?
Neurons lost from the spinal cord will lead to loss of muscle, while remaining neurons adopt muscle fibers and control larger units of muscle cells, causing these units to become less efficient (this weakds to weakness)
What can cause neuron cell death resulting in muscle atrophy (sarcopenia)?
Stroke and neural disease
What is though to contribute to physiological anorexia?
- Diminished sense of smell and taste
- Increased cytokine activity
- Delayed gastric emptying
- Altered gastric distention
- Hormonal
What are % of developed reduced sense of smell and taste in
Subjects 65-80
Subjects over 80
Subjects under 50
- More than 60%
- More than 80%
- Less than 10%
What does decline in sense of smell result in?
Decreased food intake and it can influence type of food eaten (associated with reduced interest in and intake of food)
What else does reduced sense of taste tend to cause?
Less varied diet and consequently developed micronutrient deficiencies
What is a theory of the cause of loss of taste?
Reduction in number of taste buds
What might loss of smell be affected by?
Modification in olfactory epithelium, receptors, and neural pathways
What drugs can affect taste?
Parkinson medications and antidepressants
What have studies shown improvements of food flavor can do?
Improve nutritional intake and body weight in nursing home patients
What are higher circulating levels of IL-1, IL-6, and TNF-alpha associated with?
Reduced muscle mass
What are common GI complaints in geriatrics?
Increased fullness and early satiation during meals
What can cause increased fullness and early satiation during meals?
Changes in GI sensory function (with age there is reduced sensitivity to GI distension
Aging is associated with impairment of receptive relaxation of gastric fundus…what does this lead to?
Rapid antral filling and distension and earlier satiety
What controls hunger and satiety?
The hypothalamus
What part of the hypothalamus has the neurons that release neuropeptide Y (NPY)?
The nucleus arcuatus
What does NPY do?
Mediates hunger and inhibit satiety
What else is produced in the nucleus arcuatus that stimulates satiety?
Pro-opiomelacortin
What affects the hypothalamus hunger-satiety control regulation?
Peripheral hormones
What is a prototypical satiety hormone released in the proximal bowel?
CCK
What is CCK released in response to?
Nutrients from the antrum (particularly lipids and proteins)
Is CCK increased or decreased in older people?
It is increased in older people and correlates with high levels of satiety and low hunger
Where is PPY released from?
The distal intenstine
What stimulates the release of PPY?
The presence of nutrients in the lumen
What does PPY do?
It inhibits NPY and causes satiety
What are 2 hormones that are enteric peptides involved in GI motility in response to eating?
CCK and PPY
What can cause prolonged satiety by slowing antral emptying?
High levels of fasting and postprandial CCK and PPY
What is leptin?
A hormone produced by adipose cells whose main role is maintaining energy balance
What does low leptin signal?
Loss of body fat and need for energy intake
What does high leptin signal?
Adequate body fat and no need for further energy intake
Do old people have high or low levels of leptin?
HIGH
What does insulin do?
Regulates glucose metabolism
True or False: Insulin is a satiety hormone
True
How does insulin work?
It enhances leptin signal to hypothalamus and inhibit ghrelin
What does ghrelin do?
It is the only known peripheral hormone that stimulates appetite…it is produced and secreted in endocrine mucosa to enhance food intake
Aging is associated with reduced glucose tolerance and elevated insulin levels…what might this do?
Amplify leptin signal
Inhibit ghrelin
What are signs on general impression that might indicate nutritional deficiencies?
- Wasted, thin individual with dry scaly skin and poor wound healing
- Hair is thin
- Nails are spooned and depigmented
- Patients complain of bone and joint pain and edema
Dry scaly skin
Zinc/essential fatty acids
Follicular hyperkeratosis
Vitamin A, C
Petechiae
Vitamin C, K
Photosensitive dermatitis
Niacin
Poor wound healing
Zinc, Vitamin C
Scrotal dermatitis
Riboflavin
Thin/depigmented hair
Protein
Easy pluckability (hair)
Protien/Zinc
Transverse depigmentation in nail
Albumin
Spooned nail
Iron
Night blindness
Vitamin A
Conjuntival inflammation
Riboflavin
Keratomalacia
Vitmain A
Bleeding gums
Vitamin C, Riboflavin
Glossitis
Niacin, pyridoxine, riboflavin
Atrophic papillae
Iron
Hypogeusia
Zinc, Vitamin A
Thyroid enlargement
Iodine
Parotid enlargement
Protein
Diarrhea
Niacin, Folate, B12
Hepatomegaly
Protein
Bone Tenderness
Vitamin D
Join Pain
Vitamin C
Muscle Tenderness
Thiamine
Muscle Wasting
Protein, Selenium, Vitamin D
Edema
Protein
Ataxia
Vitamin B12
Tetany
Calcium, Magnesium
Paresthesia
Thiamine, Vitamin B12
Ataxia
Vitamin B12
Dementia
Vitamin B12, niacin
Hyporeflexia
Thiamine
Do pathological factors of weight loss become more common with age?
Yes
Are most pathological causes of weight loss treatable and what can the treatments be?
Medical, social ,psychological
What are some medical causes of weight loss?
- Cardiac [e.g. chronic heart failure]
- Respiratory disease [e.g. COPD]
- Gastrointestinal [e.g. malabsorption syndromes, dysphagia, H. pylori, atrophic gastritis]
- Endocrine disorders [e.g. diabetes, thyrotoxicosis]
- Neurological [e.g. stroke, Parkinson disease, motor neuron disease]
- Infection [e.g. pneumonia, UTI]
- Malignancy
- Physical disability [e.g. arthritis]
- Alcoholism
- Poor dentition
- Drugs
What are some CV drugs to cause weight loss?
Amiodarone, furosemide, digoxin, spironolactone
What are some neurological drugs to cause weight loss?
Levodopa, fluoxetine, lithium
What are some GI drugs to cause weight loss?
H2 antagonists, PPI
What are some antibiotics to cause weight loss?
Metronidazole, griseofulvin
What are some MSK drugs to cause weight loss?
Colchicine, NSAIDs, penicillamine, methotrexate
Do all chemo drugs cause weight loss?
YES
What are some psychological causes of weight loss?
- Delirium
- Dementia/Alzheimer disease
- Depression
- Anxiety
- Alcoholism
- Bereavement
What are some social causes of weight loss?
- Poverty
- Isolation
- Inability to shop, prepare, and cook meals
What were all of the above diseases and conditions associated with?
Higher rates of malnutrition in older people
What % of 65-74 year olds use dentures?
59% (Lots of old people don’t have their won teeth)
What can poor dentition and ill-fitting dentures do?
Limit the type and quanitiy of food eaten
What are chewing problems associated with?
Greater likelihood of poor health and decreased quality of life
What % of weight loss seen in outpatients and nursing home is due to depression?
30-36%
-Depression is common in older people (2-10% of community) and a common presentation of depression is loss of appetite and weight loss
What is the relationship between energy intake and cognition that has been shown in hospital patients with dementia?
INVERSE
What % of Alzheimer disease patients cannot feed themselves 8 years post-diagnosis?
50%
What changes occur in Alzheimer patients that may affect food intake?
Olfactory changes
What social situation causes people to eat less?
Older people living on their own and socially isolated eat less (you eat up to 50% more with company)
What is associated with dementia in the late stage of the disease?
Weight loss and changed behavior
