MMSE, Mini‐Mental State Examination; MOCA, Montreal Cognitive Assessment; SPPB, Short Physical Performance Battery.
Bed rest reduces muscle protein synthesis and induces a loss of lean body mass, a model that simulates sarcopenia due to inactivity. Essential amino acid supplementation has been shown to stimulate muscle protein synthesis in healthy volunteers to a greater extent than meals, intact proteins, or similar energy intake. Continued stimulation of muscle anabolism positively affects the preservation of lean body mass and the amelioration of functional decrement throughout inactivity. However, in the setting of critical illness, the loss of lean body mass is exacerbated by persistent hypercortisolaemia. Although essential amino acids promote muscle anabolism during hypercortisolaemia, it is unlikely that a nutritional intervention alone would be effective in maintaining lean body mass during severe stress or prolonged hypercortisolaemia.82
During hospitalization, comprehensive management of nutritional risk, including nutritional support and early exercising, does not produce a significant body weight increase but prevents loss of functional independence,83 particularly in those with bed rest.84
Several studies suggest a potential benefit of creatine, especially when combined with exercise, to increase phosphocreatine stores in the muscle and replenish phosphocreatine and adenosine triphosphate, but more studies are needed to confirm these findings. In patients with chronic obstructive pulmonary disease (COPD), combined daily supplementation with creatine 340 mg and 320 mg coenzyme Q‐Ter resulted in increased lean body mass and exercise tolerance as compared to placebo.85
Palliative treatment of anorexia
Various orexigenic stimulants to improve body weight have been studied. Corticosteroids have improved appetite but have not demonstrated a gain in body weight in clinical trials. Cyproheptadine has been shown to increase appetite in cancer patients without weight gain. Cannabinoids (dronabinol, marinol, and nabilone) have shown promise in improving mood and appetite in cancer patients and AIDS cachexia. Thalidomide, a tumour necrosis factor inhibitor, has produced body weight gain in a small number of patients with HIV‐associated wasting syndrome.
Of the pharmacological agents demonstrated to produce weight gain in patients with anorexia and cachexia, megestrol acetate has been the most widely studied agent. In a meta‐analysis of 26 trials, megestrol acetate was found to increase appetite, produce weight gain, and improve health‐related quality of life in oncology patients, compared with placebo. In AIDS patients, increased weight was demonstrated. Only oedema was significant as an adverse event.86
Steroids and hormonal agents such as megestrol acetate are currently widely used in the treatment of cachexia and anorexia. They act through multiple pathways, such as increasing neuropeptide‐Y levels to increase appetite and downregulating proinflammatory cytokines. Pharmacological treatment of anorexia with agents that modulate cytokine production may produce weight gain in cachexia states. The action of thalidomide has been linked to inhibition and degradation of TNF‐α.87 The results of these pharmacological trials raise the interesting hypothesis that the improvement in appetite and weight gain may be related to their effect on cytokines.
Conclusion
Involuntary weight loss has an intensified effect on mortality and disability risk and is usually associated with clinical illness. Some data suggest that even voluntary weight loss in older people may carry a higher mortality risk. Body weight is an easily obtained clinical measurement, and weight loss is a profound marker for adverse outcomes.
The etiological investigation is fundamental with inflammation grading and may be included in the comprehensive gerontological assessment procedure. Integrative care focused not only on body weight but also on physical function and quality of life