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

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.