This review explains starvation as both a physiologic process and a disease. It includes a detailed explanation of the modifying effects of metabolic adaptation and systemic inflammation, as interpreted in a clinical context. It navigates the reader through the difficult shoals of vague and conflicting terminology that burden this topic and provides current definitions and nuanced explanations of the important but frequently misunderstood terms related to starvation and its modifiers and consequences. It provides a succinct explanation of the physiology of total fasting and its clinical correlates. Finally, it explains the interactions among starvation, sarcopenia, frailty, involuntary weight loss, systemic inflammation, cachexia, and disuse muscle atrophy. The multiple and interacting causes of generalized muscle atrophy are pointed out. Inadequate appreciation of these interactions can result in failure to diagnose and treat starvation-induced diseases. A clinical approach to involuntary weight loss is outlined.
This review contains 6 figures, 2 tables and 56 references
Key words: adaptation, cachexia, frailty, hypoalbuminemia, inflammation, ketosis, kwashiorkor, malnutrition, marasmus, muscle atrophy, protein-energy malnutrition, sarcopenia, starvation, systemic inflammation, weight loss
The Involuntary Weight Loss of the Elderly: Rheumatic Disorders
