Blood Pressure Response in Relation to Blood Lactate During Exercise in Patients with Essential Hypertension

Abstract

Thirty-four untreated patients with essential hypertension WHO I-II, 17 patients under treatment with (β-blockade, and 32 healthy controls with a wide range of exercise capacity were studied at loadless pedaling (W₀) and at the work load eliciting a blood lactate concentration corresponding to 4 mmol × 1^-1 (onset of blood lactate accumulation or OBLA). At W₀ the treated patients had approximately the same systolic blood pressure (SBP) as the healthy controls, while the untreated patients had a higher SBP than the controls. At W_OBLA SBP was higher in the untreated patients than in both the treated patients and the healthy controls. On an individual basis it was found in the healthy controls and the untreated patients that the SBP at W_OBLA showed a slight and insignificant increase versus SBP at W₀, whereas the difference in SBP between W_OBLA and W₀ (“exercise SBP increase”) demonstrated an inverse relationship (P < 0.001-0,01) versus W₀. It was suggested that for both healthy controls and untreated patients the exercise SBP depended on a “basal” level as depicted by W₀ and a further SBP increase due to the exercise load. The difference between the two groups was that the patients with untreated hypertension displayed their relationships at higher pressure levels indicating the presence of a hyperkinetic drive.

The treated patients appeared to have a lower increase in SBP between W₀ and W_OBLA than any other group, suggesting an unfavorable effect of the β-blockade.

Key words

hypertension - β-blockade - exercise blood pressure - blood lactate