Lack of an association between the presence of tumor necrosis factor or interleukin-1 alpha in the blood and weight loss among elderly patients.

To determine the association between blood cytokine levels and body weight loss in elderly patients, serum levels of cachectin/tumor necrosis factor alpha (TNF) and interleukin-1 alpha (IL-1) were measured with specific and sensitive ELISA systems. Of the 19 healthy young subjects, two (10.5%) had detectable levels of serum TNF and one (5.3%) was positive for IL-1. In the healthy elderly group, two of the 12 subjects (16.7%) had measurable TNF levels and four (33.3%) had elevated IL-1 levels. Of the 61 ambulatory elderly patients, 31.1% had serum that contained TNF and 22.9% had IL-1. Similar proportions were found in 127 nursing home patients. None of the common diseases examined in this study nor any commonly used medications were associated with increased serum cytokine levels. Patients with weight loss of more than 5 lbs were less likely to have elevated serum TNF and IL-1 levels compared to the rest of the group. It is concluded that although elevated levels of TNF or IL-1 may occur more frequently in older groups, there is no evidence for a causal relationship between these circulating cytokines and clinically significant weight loss in the elderly.