Anthropometry in special and selective conditions and circumstances: Anthropometry as measure of risk in COPD patients

Abstract

In the last decade, Chronic Obstructive Pulmonary Disease (COPD) has been redefined and newly approached not only as an airway-disease condition, but as a multi-component disease including extra-pulmonary manifestations, such as peripheral muscle weakness and malnutrition. The evaluation of body composition (as a part of nutritional assessment) fairly integrates the simple body mass index (BMI) measure by measuring the individual's active metabolism (fat free mass, FFM). Indeed, BMI and FFM are both parameters correlated with many COPD-strong outcomes. In several epidemiological studies of COPD population admitted to both in- or outpatient rehabilitation programmes, the estimated prevalence of weight loss ranges from 17% to 53%. Nonetheless, weight reduction, together with FFM depletion, is a common feature in emphysema as well as in chronic bronchitis. A nutritionally depleted patient is usually defined by a BMI of ≤ 20 kg/m2. Several studies aimed at evaluating the prognostic value of BMI in COPD patients have documented that BMI ≤ 25 kg/m2 and weight reduction of >3 kg/m 2 are strong predictors of mortality. Moreover, other studies confirmed that FFM and measurement of the cross-sectional area of muscle mass (mid-thigh and mid-arm) also correlate to survival rates. In future research, studies looking at other anthropometric, metabolic and functional factors able to predict the long-term survival should be welcomed in patients with other diseases, such as pulmonary fibrosis, similarly leading to chronic respiratory failure.