BLOOD-PRESSURE RESPONSES TO EXERCISE AS PREDICTORS OF BLOOD-PRESSURE LEVEL AFTER 5 YEARS

There is considerable disagreement in the literature on the clinical u sefulness of exercise testing as a tool for prediction of future hyper tension. Much of the discrepancy between various reports is attributab le to the difficulties of blood pressure (BP) measurement during exerc ise. Therefore, we investigated whether accurate intraarterial. BP mea surement will increase the predictive power of exercise testing. The B P responses to dynamic and isometric exercise were evaluated in 97 hea lthy, unmedicated men, of whom 34 were normotensive (NT), 29 borderlin e (BHT), and 34 mildly hypertensive (HT) using three criteria: 1) achi eved BP during the test, 2) the change of the BP from baseline to exer cise, and 3) the group was divided into high responders (HIGH, n = 19, systolic BP greater than or equal to 220 and diastolic BP greater tha n or equal to 105 mm Hg) and normal responders (n = 60). Five years la ter the BP was reassessed by casual measurements and noninvasive ambul atory 24-h monitoring (NAME) in 79 (81%; 27 NT, 24 BHT, and 28 HT) sub jects. The achieved isometric BP correlated well with the follow-up BP (casual systolic BP r = 0.43, diastolic BP r = 0.45, and NAME systoli c BP r = 0.44, diastolic BP r = 0.58, P < .001). However, achieved dyn amic BP showed a poorer relationship to future BP (r range, 0.09 to 31 , P = NS to P < .01). Because the intraarterial preexercise sitting BP also correlated well with follow-up BP (r range, 0.33 to 0.48, P < .0 1 to P < .001), and the r values were close to those of achieved isome tric BP we used multiple regressions (including all resting and exerci se BP values as independent variables) to evaluate the contributions o f the baseline and exercise values for prediction of the follow-up BP. The baseline value explained 12% to 23% (from casual diastolic BP to NAME diastolic BP, systolic BP values) of future BP variance, whereas achieved isometric BP ranged an additional 1% to 11% (from casual syst olic BP to NAME diastolic BP) of variance. In general, BP change from baseline with stressors did not correlate with follow-up measurements. In the high responder group the achieved dynamic BP did not correlate significantly with the followup BP, whereas the achieved isometric di astolic BP did correlate (casual diastolic BP r = 0.56, P < .05, NAME systolic BP and diastolic BP r = 0.52, P <.05). Both groups had simila r future BP levels. In conclusion, even with very accurate BP readings the reactivity to dynamic exercise is a weak predictor of future BP, and does not improve the prediction compared to resting BF values. Int raarterial BP response to isometric exercise marginally improves the p rediction of future BP levels. (C) 1997 American Journal of Hypertensi on, Ltd.