Biochemical changes and endocrine responses in cystic fibrosis in relation to incremental maximal exhaustive exercise

The purpose of this study was to compare biochemical changes and endocrine responses during an incremental maximal bicycle test in three well-trained 18-year-old patients with cystic fibrosis (CF) and in three healthy controls. Although the blood concentration at rest of the white cell count, haptoglobin, phosphorus, urea, creatinine, and uric acid were somewhat different in the two groups, the CF patients had similar biochemical changes in response to the exercise compared with the healthy men. The endocrine responses to exercise seemed to be different between the two groups with regard to changes in cortisol, growth hormone, and testosterone concentrations. The differences, however, were probably caused by differences in age, training situation, and psychological stress reaction rather than by pathological mechanisms.