Simple starvation vs stress starvation and selective protein malnutrition vs total caloric malnutrition. cachexia

Malnutrition is defined as a pathological state caused by a lack of nutrients. Advanced stages of malnutrition are called cachexia, and the highest degree of cachexia is marasmus.

Deficiency (carence) is an isolated lack of one of the essential nutritional factors (vitamins, trace elements, essential fatty acids).

Causes of malnutrition are conditions associated with reduced intake, increased loss of nutrients, or increased metabolic demands.

In simple starvation the body adapts by lowering its metabolic rate and using fat stores while largely preserving protein, so the process is slow and non-inflammatory. In stress starvation, such as during illness or trauma, inflammatory cytokines prevent this adaptation, metabolism speeds up, and the body rapidly breaks down protein and lean tissue, leading to much faster deterioration.

Risk factors

• hospitalization (30–60%)
• chronic disease
• elderly people
• children
• socioeconomic factors (food scarcity, isolation)

Classification of malnutrition

• acute - develops over several days, usually due to sudden lack of intake or illness
• subacute - develops over several week, gradual and noticeable decline
• chronic - develops over several months, with long-term developmental consequences

• primary = endogenous – insufficient/excessive intake of nutrients; anorexia, nausea
• secondary = exogenous – disorders of absorption, utilization of nutrients, increased nutritional demands, drug interactions; GI diseases, bleeding, diarrhea; fever, infections, tumors, surgery, trauma, burns) + frequent combination (e.g., anorexia)
  • In secondary malnutrition, regulatory mechanisms and protein catabolism are impaired.

• general - lack of energy in food intake
• specific malnutrition - deficiency/excess of individual nutrients

Types of starvation (protein-energy malnutrition):

• Energy (caloric) malnutrition – simple starvation, exemplified by patients with anorexia nervosa.
• Protein deficiency – protein malnutrition, known as the kwashiorkor type.
• Mixed malnutrition - in clinical practice both deficits are usually present together

Marasmus

Marasmus is a deficiency of all macronutrients: carbohydrates, fats, and protein due to an isufficient intake of energy and proteins. Fat and glycogen stores are depleted and eventually breakdown of active muscle mass and body proteins occurs. Edema isn't present.

Child with marasmus

Clinical manifestation:

• symmetrical reduction of fat and fat-free mass → general weight loss, cachectic appearance
• loose skin visible in folds due to the loss of protein and fat
• brittle hair and nails
• lethargy, apathy, weakness
• normal albumin levels, preserved immune reactivity

Kwashiorkor

Children with kwashiorkor

Kwashiorkor is a deficiency in protein predominantly, as well as some other key nutrients. The organism is unable to use carbohydrates and lipids for energy and hypercatabolism persists as the body breaks down muscle and plasma proteins. Fat stores aren't reduced.

Causes: stress-induced, cytokine-induced malnutrition (IL-1, IL-6, TNF-α), protein deficiency (lack of protein in diet)

Clinical presentation:

• preserved fat stores, not severely reduced weight,
• hypoproteinemia → edema most visible around the ankles (gravity)
• swollen face and belly (ascites)
• reduced visceral proteins and lymphocytes, elevated CRP
• poor wound healing, pressure ulcers, frequent infections (MODS, sepsis);
• stunted growth in children

Marasmic kwashiorkor

Combination of marasmus and kwashiorkor. It occurs when a child with kwashiorkor does not consume enough calories and it is the most severe protein-energy malnutrition.

Clinical manifestation:

• combination of the manifestation of kwashiorkor and marasmus - edema, wasting...

Cachexia

Cachexia (wasting syndrome) is a serious complication of severe chronic diseases due to an increased demand of energy. It often begins as simple starvation, later regulatory mechanisms fail and proteocatabolism increases.

Clinical manifestation:

• physical weakness and fatigue
• weight loss and muscle mass loss
• loss of apetite

Causes: malignant tumors (competition for nutrients between tumor and host), inflammatory diseases, AIDS (wasting syndrome)

References

1. PASTOR, Jan. Langenbeck's medical web page [online]. ©2006. [cit. 14.11.2010]. <https://langenbeck.webs.com/interna.htm>.
2. Protein-energy malnutrition [online]. AMBOSS;. Link: https://www.amboss.com/us/knowledge/protein-energy-malnutrition/
3. Atassi H. Protein-Energy Malnutrition [online]. eMedicine / Medscape. Link: https://emedicine.medscape.com/article/1104623-overview?form=fpf