Wasting

In medicine, wasting, also known as wasting syndrome, refers to the process by which a debilitating disease causes muscle and fat tissue to "waste" away. Wasting is sometimes referred to as "acute malnutrition" because it is believed that episodes of wasting have a short duration, in contrast to stunting, which is regarded as chronic malnutrition. According to the latest UN estimates, an estimated 52 million children under 5 years of age, or 8%, were wasted in 2011. The vast majority, about 70%, of the world's wasted children live in Asia, most in South-Central Asia.^[1]

Causes

Wasting can be caused by an extremely low energy intake (e.g., caused by famine), nutrient losses due to infection, or a combination of low intake and high loss. Infections and conditions associated with wasting include tuberculosis, chronic diarrhea, AIDS, and superior mesenteric artery syndrome. The mechanism may involve cachectin - also called tumor necrosis factor, a macrophage-secreted cytokine. Caretakers and health providers can sometimes contribute to wasting if the patient is placed on an improper diet. Voluntary weight loss and eating disorders are excluded as causes of wasting.

Classification

• Children: Weight-for-height (WFH). In infants under 24 months, recumbent (supine) length is used. WFH as % of median reference value is calculated this way:

$\mathrm{WFH} = \frac{\mbox{weight of a given child}}{\mbox{median weight for a given child of that height}} \times 100$

Cutoff points may vary, but <80% (close to -2 Z-score) is often used.

• Adults:
  • Body Mass Index (BMI) is the quotient between weight and height squared (kg/m²). An individual with a BMI < 18.5 is regarded as a case of wasting.
  • Percent of body weight lost (At Tufts, an unintentional loss of 6% or more in 6 months is regarded as wasting)

Treatment

Antiretrovirals and anabolic steroids have been used to treat HIV wasting syndrome.^[2] Additionally, an increase in protein-rich foods such as peanut butter, eggs, and cheese can assist in controlling the loss of muscle mass.^[3]

See also

• Atrophy
• Cachexia
• Weight loss
• Anorexia
• Superior mesenteric artery syndrome

References

1. United Nations Children’s Fund, World Health Organization, The World Bank. UNICEFWHO- World Bank Joint Child Malnutrition Estimates. (UNICEF, New York; WHO, Geneva; The World Bank, Washington, DC; 2012)
2. Michael Powers, "Performance-Enhancing Drugs" in Joel Houglum, in Gary L. Harrelson, Deidre Leaver-Dunn, "Principles of Pharmacology for Athletic Trainers", SLACK Incorporated, 2005, ISBN 1-55642-594-5, p. 330
3. http://www.hiv.va.gov/patient/diagnosis/OI-wasting-syndrome.asp

External links

• Chronic Wasting Disease and Potential Transmission to Humans, Center for Disease Control and Prevention
• Unintentional Weight Loss/Wasting, Tufts University Nutrition/Infection Unit