A Review On the Occurrence, Causative Factors and Pattern Of Malnutrition In Patients With Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a disease of the respiratory system characterised by extra pulmonary manifestations that includes nutritional depletion, which is known to have negative consequences on morbidity and mortality. Chronic malnutrition results in reduced lung and respiratory muscle function secondary to loss of lean body mass, multiple nutrient deficiencies and cachexia when chronic in nature. A literature review was performed on the prevalence and trend of malnutrition, reported in COPD patients. Increased resting energy expenditure, thermic response to food, early satiety, increased pro inflammatory cytokines are known to lead to loss of appetite, weight loss and cachexia on a long term. Under nutrition among various study populations is reported between 20-70% and cachexia in 27-33% of subjects with COPD. Malnourished individuals are exposed to higher risk of mortality, morbidity and poor prognosis by the reduced pulmonary function and risk of infections due to the loss of fat free mass, skeletal muscle strength, lower immune function secondary to malnutrition. Pre-existing oxidative stress can be further worsened by deficits in micronutrient intakes. Anthropometric assessment including fat free mass is important in evaluating nutritional depletion as some COPD patients may lose fat free mass without any alterations in fat mass. Thus, COPD patients can suffer from malnutrition, further aggravated by the severity of symptoms, biochemical alterations and severity of disease. Further, undernutrition can negatively affect the prognosis necessitating a thorough assessment of body composition along with somatic status among patients losing weight and those with a history of weight loss.