Effects of megestrol acetate on circulating interleukin-15 and interleukin-18 concentrations in healthy elderly men.
BACKGROUND
Interleukin-15 (IL-15) and interleukin-18 (IL-18) are potential regulators of body composition in humans. The authors previously reported that megestrol acetate ingestion causes a large accumulation of adipose tissue and reduces muscle mass. Therefore, the purpose of this investigation was to evaluate the effects of megestrol acetate ingestion on circulating IL-15 and IL-18 concentrations in healthy elderly men.


METHODS
All participants received 800 mg of megestrol acetate per day during this 12-week study. Megestrol acetate was combined with testosterone injections (100 mg/week), placebo injections, resistance training, or resistance training and testosterone. Resting IL-15 and IL-18 concentrations were measured by enzyme-linked immunosorbent assay at week 0 (pre), week 6 (mid), and week 12 (post).


RESULTS
The time effect for IL-15 was significant (p = .0008), with the mid and post values being significantly greater than the pre value. The change in IL-15 concentration was not significantly related to the change in muscle mass (r = -.31; p > .05), nor was it related to the change in fat mass (r =.17; p > .05). Differences among groups or over time were not significant for IL-18, nor were correlations between pre body weight and pre IL-18 (r = -.03), pre fat mass and pre IL-18 (r = .14), or the change in fat mass and the change in IL-18 (r = -.07).


CONCLUSIONS
IL-15 was increased as a result of megestrol acetate ingestion; however, megestrol acetate did not affect circulating IL-18 concentrations, and the change in IL-18 did not correlate with any body composition variables.
Lambert
Charles P
CP
Nutrition, Metabolism, and Exercise Laboratory, Donald W. Reynolds Center on Aging, University of Arkansas for Medical Sciences, Central Arkansas Veterans Health System, Little Rock, AR 72205, USA. lambertcharlesp@uams.edu
Flynn
Michael G
MG
Sullivan
Dennis H
DH
Evans
William J
WJ
D000368:Aged; D001823:Body Composition / Q000187:drug effects; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D019409:Interleukin-15 / Q000097:blood*; D020382:Interleukin-18 / Q000097:blood*; D008297:Male; D019290:Megestrol Acetate / Q000494:pharmacology*; D008875:Middle Aged; D013739:Testosterone / Q000494:pharmacology
D019409:Interleukin-15; D020382:Interleukin-18; D013739:Testosterone; D019290:Megestrol Acetate