Changes in body composition, muscle function and energy expenditure after radical cystectomy

Abstract

Objective: To determine the changes in body composition, muscle function and energy expenditure after radical cystectomy (RC).

Patients and methods: Eleven consecutive men (median age 66 years, range 44-79) who had a RC over a 1-year period had measurements made of their total body protein, by neutron-activation analysis, total body water by tritium dilution, total body potassium by whole-body counting, resting energy expenditure by indirect calorimetry, and grip strength and respiratory muscle strength. These variables were measured on the day before surgery and at 2 weeks and 6 months after RC. Total body fat was derived using a multicompartment model. Artificial nutritional support was not provided after RC and no oral caloric intake was provided until bowel function returned.

Results: Five patients were malnourished before RC and four had significant complications afterward. Over the first 2 weeks there were significant losses in mean (sem) protein levels, at 0.68 (0.17) kg (P < 0.001) and water, at 3.00 (0.73) L (P < 0.001), while body fat was unchanged. Resting energy expenditure was 11% higher than predicted at 14 days after RC (P < 0.001). Body potassium changes mirrored the protein changes but were not statistically significant. Over the subsequent 6 months, 63%, i.e. 0.43 (0.24) kg, of the body protein lost after surgery was regained. Muscle function had returned to baseline levels at 6 months.

Conclusions: This study shows that the catabolic loss of body protein after RC is not regained by 6 months. Regimens directed at early nutritional support after RC for these patients might improve the recovery of body composition, with consequent clinical benefits.