Exaggerated BP response to exercise predicts stroke

The risk of stroke increases with growing difference between resting and maximal exercise systolic blood pressure (SBP), independent of BP at rest, according to a study. This suggests that an exaggerated BP response to physical exercise is independently predictive of stroke.

This study examined baseline data of 1,392 participants, out of the 2,014 men included in the Oslo Ischemia Study in the 1970s, who remained healthy and performed bicycle exercise tests both at baseline and 7 years later. Participants were divided into quartiles based on the difference between resting and maximal SBP (ΔSBP) at baseline.

The investigators used Cox proportional hazard to assess the risk of stroke, adjusting for resting BP, age, smoking, serum cholesterol, and physical fitness. They followed participants until the first ischaemic or haemorrhagic stroke through 35 years.

Of the 195 incident strokes, 174 (89 percent) were ischaemic. Univariate analyses revealed significant positive associations of stroke risk with age, resting SBP, resting diastolic BP, and SBP at moderate and maximal workload.

In multivariate analysis, a 2.6-fold increased risk of stroke (p<0.0001) was observed in ΔSBP quartile 4 (ΔSBP >99 mm Hg) relative to ΔSBP quartile 2 (ΔSBP 73–85 mm Hg), which had the lowest risk of stroke. Moreover, ΔSBP quartile 1 had a 1.7-fold higher stroke risk than quartile 2, indicating a J-shaped association to such risk.

“Previous research has shown an association between moderate workload exercise BP and coronary disease, whereas maximal exercise BP is associated with stroke,” the investigators said.