Pathophysiology of weight loss in older persons.

It is now well recognized that a physiological anorexia of aging occurs that is associated with gradual weight loss in older persons [1, 2]. A number of epidemiological studies have shown that weight loss in older persons leads to death (fig. 1) [3–6]. In addition, weight loss has been shown to be associated with hip fracture [7]. When an older person develops a disease, the disease interacts with the propensity for anorexia, leading to severe weight loss and cachexia. The Hebrew physician, Maimorides differentiated between sarcopenia and cachexia: ‘...for wasting which resembles old age (sarcopenia) and wasting which is secondary to fever (cachexia) and wasting which is called doalgashi (starvation)’. The differences between the three forms of weight loss are delineated in table 1. In nursing home residents who were losing weight, it was shown that those who could reverse their weight loss had a much lower mortality rate than those who continued to lose weight [8]. The Cochrane collaboration found that caloric supplementation decreased mortality [9].