| Popis: |
The treadmill test (TM), handgrip test (HG) and cold-pressor test (CP) are now frequently used clinically for multiple purposes. However, gas exchange analysis has not been a common procedure during HG. In particular, during CP, it has not been previously reported. Relationships between these 3 tests and blood pressure, heart rate (HR), respiratory gas exchange and the sympathetic nervous activity of normal subjects have not been reported, either. This study was undertaken to clarify these points. Symptom-limited TM was performed in 11 normal male subjects with a mean age of 45 +/- 8 yrs according to the Bruce protocol, with the HG using the weight-sustaining method (equal weight of 50% maximal voluntary contraction) for 3 min, and CP for 2 min. Systolic and diastolic blood pressures (Ps, Pd) were recorded; HR was measured every 30 sec, and gas exchange variables, such as oxygen uptake (VO2) and carbon dioxide production, were documented every 10 sec using an aereomonitor AE-280 (Minato Medical Science Co). In 10 of 11 subjects, concentrations of plasma noradrenaline (PNA) and plasma adrenaline (PAD) were measured at rest and at the times of peak values of the 3 tests. The peak values of Ps and HR were much higher during TM than during HG and CP (p0.01), while the peak values of Pd during HG and CP were higher than during TM (p0.01). The VO2 increased significantly for all of the 3 tests (TM: +781%, HG: +65%, CP: +20%), with the increment being the greatest during TM. Both PNA and PAD increased significantly for the 3 tests, with the increments of PNA and PAD being the greatest during TM. The percent change in PAD was more prominent during HG and CP than during TM. This tendency was not as clear for PNA as for PAD. There was no correlation of delta Ps and delta Pd between the 3 tests, but values of delta HR correlated partially. No significant correlations of peak VO2 were observed between the 3 tests. The peak PNA correlated between HG and CP (r = 0.77, p0.01), and the peak PAD correlated between TM and CP (r = 0.67, p0.05). In summary, numerous differences in hemodynamic and respiratory responses and in sympathetic nervous activation were observed in the 3 tests. When the 3 tests are undertaken, careful attention should be paid for their characteristics, discrepancies and limitations. |
