Aim. The aim of our study was to evaluate the haemodynamic and the respiratory response to exercise in patients with hyperthyroidism before and 30 days after normalized thyroid hormones levels. These findings were compared with those of 10 control patients. Methods. Thirty patients (23 women, aged 34.3±12 years) with untreated hyperthyroidism were studied. Twenty-four patients were treated with methimazole, 13 of which were also treated with propranolol. Six patients underwent surgery. A symptom-limited cardiopulmonary exercise test and an echocardiography were performed in all patients. Results. At rest patients with hyperthyroidism showed at echocardiography an increased cardiac index (P=0.006 vs euthyroid, P=0.007 v s normal) and a higher ejection fraction (P=0.008 vs euthyroid, P=0.007 vs normal). The duration of the exercise was lower in hyperthyroid patients (P=0.006vs euthyroid; P=0.0068 vs normal). Anaerobic threshold was reached at 49.6% of peak V̇O2during hyperthyroidism, at 60.8% during euthyroidism (P=0-01) and at 62% in normal (P=0.01). Work rate was lower in patients with hyperthyroidism at anaerobic threshold (P=0-01 vs euthyroid, P=0.03 vs normal) and at maximal work (P=0.0001 vs euthyroid, P=0.021 vs normal). Patients in hyperthyroidism showed a lower increment of heart rate between rest and anaerobic threshold (P=0.021 vs euthyroid, P<0.0001 vs normal) and a lower V̇O2at anaerobic threshold (P=0.03 vs euthyroid; P= 0.04 vs normal). Oxygen pulse at anaerobic threshold was significantly reduced in hyperthyroidism (P=0.04fs euthyroid, P=0.005 vs normal). Conclusion. The mean result is that after only 30 days of appropriate antithyroid treatment there was an appreciable improvement of exertion capacity.
|Titolo:||Work capacity and oxygen uptake abnormalities in hyperthyroidism|
|Data di pubblicazione:||2006|
|Appare nelle tipologie:||1.1 Articolo in rivista|