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Wednesday 19 December 2012

Nutritional diseases , nutrition1 , part B

Water-soluble Vitamins
• Water-soluble vitamins : Thiamin (B1),
Riboflavin (B2), Niacin, Vitamin B6, Folate
(Folic acid), Vitamin B12, Pantothenic acid ,
biotin, choline Vitamin C (Ascorbic acid).
• Fat- soluble vitamins: vit A, vitD , vitE , vitK

Minerals
•Minerals are simple substances found in the environment that are essential to the body’s functioning.
•Minerals are used to regulate a wide range of body processes, from bone formation to blood clotting.
•Most minerals are either quickly used or lost in waste products, therefore we must eat mineral-rich foods daily to replenish our supply. Iron is an exception –it tends to be kept and recycled by the body.


Major Minerals: calcium, phosphorus, magnesium,
potassium, sodium .
• Calcium keeps the nervous system working well
and is needed for blood clotting. Osteoporosis is
disease caused by calcium deficiency.
• Sodium and potassium help regulate the passage
of fluids in and out of cells. Too much sodium in
the diet may aggravate high blood pressure or
hypertension, increasing the risk of heart attack,
stroke or kidney disease. Table salt is one source
of sodium in the diet.

Trace Minerals: iron, iodine, manganese, zinc, copper, and fluorine
•The majority of the minerals needed for the body to function are only required in very small, or trace amounts.
•Iron is a vital part of hemoglobin – a substance in red blood cells that carries oxygen to all parts of the body. Insufficient iron may cause anemia.
•Iodine is needed for the thyroid gland to function properly. The thyroid gland produces hormones that control how quickly chemical reactions occur in our body. Too little iodine – thyroid gland enlarged. The primary sources are seafood and iodized table salt.

Standards of Nutrition
•Dietary Reference Intakes (DRIs)
–Quantitative estimates of nutrients collectively for proper function and health
•Recommended Daily Allowances (RDA)
•The average daily dietary intake that meets
the nutrient requirement of nearly all healthy persons of a specific sex, age, life style or physiological condition.

Malnutrition
Definition: loss of the lean body mass and adipose tissue due to insufficient dietary supply
1.primary : inadequate or poor-quality food intake (war or famine).
2.secondary : from diseases that alter food intake or nutrient requirements, metabolism, or absorption.
Two syndrome:
kwashiorkor (malnutrition with edema)
marasmus (malnutrition with marked muscle-wasting).


CAUSES OF malnutrition
Decreased the energy intake ( hypo metabolism)
Economic : poverty, famine
anorexia : nervosa, dementia ,depression cancer , renal failure
Abdominal pain: pancreatitis, intestinal ischemia
Impaired diet transit : benign and malignant esoph. or gastric obstruction
Maldigestion: pancreatic exocrine insufficiency, short bowel syndrome
Malabsorption : small intestinal disease(celiac disease


Causes of malnutrition
Increased energy expenditure (hyper metabolism)
Increased BMR: (thyrotoxicosis , fever, cancer trauma , sepsis, surgery,burn)
Excessive physical activity( marathone runner )
Acute and chronic inflammation : T.B ,collagen diseases.
Energy loss :(e.g. glycosuria in diabetes)
Mixed mechanisms
Disseminated cancer
Chronic inflammatory bowel disease (crohns disease


Metabolic response to the Starvation :
First day:
•Circulating glucose and FA and TGs , liver and muscle glycogen (1200 Kcal ).
•Lipolysis for the FAs production (65% of energy source )
First few days :
•Lipolysis increase and ketone body production increase
•Gluconeogenesis begin (70 g),15% from protein
2 weeks-30 days :
•Energy conserved , BMR decrease , thyroids hormones decrease , sympath. system decrease
•Lipolysis continue 150g/day (90% on fat)
•Muscle PTN breakdown decrease(20g/day)

Metabolic response to stress
•High catecholamines ,glucagon , cortisol cytokines , TNF , int 1,6
•Skeletal and visceral PTN catabolism (150 g/d)
•50 % of body protein stores within 3 weeks


Physiological consequences
1. GIT :
Atrophy of small IN. mucosa
Gastric and pancreatic secretion
Volume of bile and conjugated bile acids decrease
Carbohydrate. and fat malabsorption decrease.
2.CVS:
Myocardial Mass and function decrease
3.Immune system:
Lymphocyte count decrease
Delayed skin hypersensitivity
Decrease production of ABs

4.Respiratory:
•Structural and functional atrophy
5.Bone marrow:
•Decrease lymphocyte and WBC and RBC
6.Renal :
•Decrease mass and function
7.Skin and hair:
•Dry ,thin, wrinkled , hyperkeratosis

8.Endocine
 Low insuline
 Increase cortisol
 Increase growth homone
 T3and t4 decrease
 Primary gonadal dysfuction

Clinical features:
WT loss
Weakness and, craving for food
muscle wasting
Loss of subcutaneous fat
Leg edema and ascites
Skin dry pale lax, easy packable thin hair
amenorrhea or impotence
 Bradycardia Cold cyanosed extremities, pressure sores
distended abdomen, with diarrhea
apathy, depression, loss of the initiative
Features of associated vitamins deficiency
susceptibility to infections

INFECTIONS ASSOCIATED WITH PEM Patients:
•Gastroenteritis
•Gram-negative septicemia
•Respiratory infections, especially bronchopneumonia
• viral infection :herpes simplex
•Tuberculosis
•Streptococcal and staphylococcal skin infections
•Helminthic infestation


Nutritional Assessment
•History
•Physical examination
•Anthropometric measurements
•Laboratory investigations
•Functional test


Nutritional Assessment
History
Dietary Analysis
Dietary history Review foods eaten
Review preparation methods
Evaluate digestive and absorption adequacy
Review supplements taken
Significant weight loss within last 6 months
> 10% loss of body weight
<90% 0f ideal body weight



patient History of Weight Loss
Finding                                                                                                    Example
Involuntary diet restriction                               Poverty due to inadequate income
Anorexia                                                     Anorexia nervosa, severe depression,
dementia, cancer, chronic renal failure
Inadequate diet selection                         Chronic alcoholism, strict vegetarianism
Critical illness                                                 trauma, burn, major surgery, sepsis
Dysphagia                                                                          Esophageal obstruction
Nausea, vomiting                                                  Gastric or intestinal obstruction
Chronic abdominal pain                               chronic pancreatitis, intestinal angina
Chronic diarrhea                                                           Pancreatic, intestinal mucosal




















Lab investigations
1. Serum visceral protein:
albumin < 30 mg/dl
transferrin < 150 mmol/l
pre-albumin <12 mg/dl




2. vitamin and minerals assays:
tests reflecting specific nutritional deficits e.g. prothrombin time 3.Assessment of immune function:
Total lymphocyte count < 1800 / mm3
Skin anergy testing
Nutritional Assessment


Functional test
Hand grip dynamometry
Other
Urinary creatinine excretion:
1g of urine creatinine:18.5g of FFM
23mg/kg of ideal body wt./men
18mg/kg of ideal body wt./women
bioelectric impedance analysis


 

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