Definition:
- a complex metabolic syndrome associated with underlying
illness and characterized by loss of muscle with or without loss of fat mass.
Prominent clinical
feature:
- Weight loss in adults (corrected for fluid retention) or
growth failure in children (excluding endocrine disorders).
- Wasting disease (associated with Anorexia, inflammation,
insulin resistance and increased muscle protein breakdown)
(Note: wasting disease
is distinct from starvation, age-related loss of muscle mass, primary
depression, malabsorption and hyperthyroidism)
(Note: Cachexia is
generally associated with loss of appetite so losses of body weight and muscle
are accelerated. In such cases, the process
of cachexia may be misinterpreted as caused by malnutrition)
Cause:
- Complex and not completely understood at the present time
Discussion
1) Weight loss
- Body weight changes: highly predictive of morbidity and
mortality in cachectic patients
- At least a 5% loss of edema-free body weight during the
previous 12 months or less.
[The time frame may be
disease specific and is likely to be shorter in cancer (3e6 months) and longer
in chronic kidney or heart failure or COPD (12 months)]
- If history of weight loss cannot be documented, BMI of
<20 kg/m2 was considered sufficient to establish a diagnosis of
cachexia.
- Degree: weight
loss within previous 12 months (or less)
is >5% (mild), >10% (moderate) or >15% (severe)
2) Skeletal muscle
- Accelerated or exaggerated loss of skeletal muscle mass distinguishes
cachexia from the weight loss due solely to reduced energy intake.
- Every effort should be made to quantify body composition,
and in particular, appendicular skeletal muscle mass.
- Other criteria: decreased muscle strength, fatigue,
anorexia, low muscle mass, biochemical abnormalities (inflammation, anaemia or
hypoalbuminemia)
3) Nutritional factor
- It is important to distinguish cachexia from starvation, malabsorption,
hyperthyroidism, dehydration or sarcopenia (though these conditions may
represent a pre-cachectic state) and from subcutaneous fat loss (lipoatrophy)
- Although malnutrition is often present in cachexia, the clinical
characteristic of cachexia is that it cannot be successfully treated with
nutrition alone.
(Refeeding a patient
with cachexia does not correct the underlying problem. Even with total
parenteral nutrition, weight stabilization does not prevent the continuing loss
of skeletal muscle mass or correct the underlying abnormality in the metabolic
state)
- Cachexia is often associated with loss of appetite.
However, anorexia can occurs in other conditions that are not associated with
cachexia. For this reason, cachexia should only be diagnosed in the presence of
weight loss if at least three of the five conditions identified in Table 1.
No comments:
Post a Comment