MODERATE ENDURANCE TRAINING HAS NO EFFECT ON THE PARATHYROID FUNCTIONOF HEART-TRANSPLANT PATIENTS

The benefit of retraining for heart transplant recipients (HTR) is now well established. The rehabilitation of these patients can be comprom ised by osteopenia and bone fractures. The resting levels of parathyro id hormone (PTH) and exorcise-induced increases are higher in HTR than in healthy controls. To evaluate the effect of a moderate endurance t raining programme on parathyroid activity, six HTR, an average of 18 m onths after transplant, and seven healthy sedentary controls have been studied. None of the subjects had a history of bone disease, Two exer cise tests (square wave endurance exercise tests. SWEET) with identica l work rates were performed before and after training, Intact PTH, ion ized calcium (Ca), phosphorus (Pi) and pH were measured at rest, durin g exercise and in the recovery periods. Training consisted of a 45-min SWEET three times a week for 6 weeks. Levels of Ca2+. Pi and PTH show ed a significant increase during the exercise session in both groups. Ca2+ and Pi levels decreased rapidly after the cessation of exercise w hereas PTH reached a peak at the 10th min of the recovery in both grou ps. This increase in PTH was significantly higher in HTR than in contr ols. However, despite a significant improvement of total endurance wor k (+28% in HTR. +29% in controls) this endurance training had no effec t on resting levels of PTH, plasma Ca2+ or Pi. nor on their exercise-i nduced variations. The exercise-induced decrease in pH was less pronou nced after training which is evidence of training. We conclude that a short endurance training programme does not alter the moderate hyperpa rathyroidism of HTR. The effect of such a training programme on bone m ass and bone mineral density needs now to be evaluated.