Cachexia and pregnancy toxemia Flashcards
What is cachexia?
A metabolic wasting disorder accompanied primarily by loss of lean body mass
What diseases is commonly linked with cachexia?
- Cancer
- Congestive heart failure
- Chronic kidney disease
- COPD
Characteristics of cachexia
- Decrease in skeletal muscle mass
- With or without weight loss
- Loss of appetite
- Increased metabolic rate
Difference between cachexia and starvation
In cachexia patients, nutrients are readily available to them but they don’t have the correct response. Protein degradation begins early on even though there are carbohydrates and lipids present.
What hormone responsible for cachexia?
Tumour necrosing factor-alpha (TNF-alpha)- highly elevated in many diseases.
Role of tumour necrosing factor-alpha
- Acts on CNS. Triggers brain to decrease food intake which can lead to anorexia.
- Activates NF which leads to activation of ubiquitin-proteosome system (protein breakdown), triggers inflammation, and inhibits myogenesis
TNF-alpha metabolic effects
- Increases muscle loss
- Decreases food intake= anorexia
- Impaired glucose control by inhibited protein phosphatase 1 and IRS-1 (used to form glycogen, create fat, and increase GLUT 4)
- Increases lipid mobilization/lipolysis (by inhibiting protein phosphatase 1)
Congestive heart failure and cachexia
- Inadequate blood pumping to the body (Hypoxemia)
- ~50% of dogs with CHF display cachexia
- Strong triangular relationship between heart failure, increasing TNF-alpha levels, and muscle loss
Multifactorial cause of muscle and fat loss
- Lack of appetite
- Decreased perfusion of GI system
- Increase in inflammatory factors (enhancing muscle protein and degradation)
- Increased resting energy requirement
Cachexia with edema and ascites
Cachexia dogs show a decreased level of serum albumin which is due to an increased use of amino acids for energy, and a reduction of protein synthesis function of the liver
How do animals with cachexia lose muscle without losing weight?
Cachexia animals have increased fluid retention which can mask the muscle and fat loss in terms of overall weight.
Obesity paradox with cachexia
Animals that are diagnosed with different conditions have a decreased morbidity when they have a lower BCS (more lean). Obese animals will have an improved survival rate; the excess fat storage may be protective.
What is pregnancy toxemia?
A metabolic disease in pregnant animals caused by an imbalance between dam nutritional intake and fetal demand.
When does pregnancy toxemia occur?
Commonly occurs during late gestation.
- Large fetus size, can compress the mothers stomach and reduce appetite and therefore nutritional intake
- Negative energy imbalance created by exponential energy requirement of fetus at late gestation and reduced food intake
Primary markers of pregnancy toxemia
- Lethargy
- Anorexia (starvation response)
- Blood chem test should show hypoglycemia and hyperketonemia