Increased Blood Pressure During Exercise Could Predict Risk of CVD, Death

Vanessa Xanthakis, PhD

New research from the Boston University School of Medicine (BUSM) suggests blood pressure during and after exercise could signal an increased risk for cardiovascular disease and mortality among middle-aged patients

Results of the study, which analyzed data from the Framingham Offspring Study, found delayed blood pressure recovery following exercise was linked to a greater risk of cardiovascular disease and mortality while high blood pressure during exercise was associated with a higher risk of developing hypertension.

"The way our blood pressure changes during and after exercise provides important information on whether we will develop disease in the future; this may help investigators evaluate whether this information can be used to better identify people who are at higher risk of developing hypertension and CVD, or dying later in life," explained study investigator Vanessa Xanthakis, PhD, assistant professor of medicine and biostatistics at BUSM and an Investigator for the Framingham Heart Study, in a statement.

With little data examining associations between blood pressure responses to submaximal exercise in middle-aged patients with changes in risk of cardiovascular outcomes and mortality later in life, Xanthakis and a team of BUSM colleagues designed the current analysis to investigate the prognostic value of these blood pressure responses. Using the 1993 Framingham Offspring Study (FOS) and only including patients with data through the 1998-2001 follow-up visit, investigators identified a cohort of 3539 patients eligible for inclusion.

The design of the study called for a total of 4 analyses to be performed—examining incident cardiovascular disease and mortality, incident hypertension, left ventricular mass (LVM), and carotid intima-media thickness (CIMT), respectively. Of the 3539 patients eligible for inclusion, 1993 patients were included in the incident cardiovascular disease and mortality analysis, 1239 in the incident hypertension analysis, 1660 in the LVM analysis, and 1534 in the CIMT analysis.

Of note, each analysis excluded FOS patients with those specific conditions at enrollment in 1993.

As part of examination 7 (1998-2001) of the FOS, participants took part in a submaximal exercise test conducted using Bruce protocol on a treadmill. Additionally, exercise blood pressure was recorded twice during the test and blood pressure recovery was recorded at the end of each minute for 4 minutes of the recovery phase in a supine position.

For the purpose of their primary analysis, Xantahkis and colleagues used 4 variables derived from the aforementioned blood pressure recordings—exercise systolic blood pressure (SBP), exercise diastolic blood pressure (DBP), SBP recovery, and DBP recovery. In a secondary analysis, investigators created 4 different variables from the recordings—change in exercise SBP, change in exercise DBP, 3 minutes postexercise SBP, and 3 minutes postexercise DBP.

Upon analysis, results indicated each standard deviation (SD) increment of exercise SBP and exercise DBP was associated with higher log-transformed LVM (SBP, β=0.02, P <.001; DBP, β=0.01, P=.004) and each SD increment in exercise SBP (β=0.08, P <.001) was associated with increased CIMT. Results also suggested each SD increment of exercise blood pressure was associated with a greater risk of incident hypertension (SBP, HR, 1.40; 95% CI, 1.20-1.62; DBP, HR, 1.24; 95% CI, 1.11-1.40) and cardiovascular disease (DBP, HR, 1.15; 95% CI, 1.02-1.30).

Investigators observed rapid blood pressure recovery was associated with lower log LVM and CIMT.

Final results of the multivariable-adjusted analyses indicated HRs of 0.46 (95% CI, 0.38-0.54) and 0.55 (95% CI, 0.45-0.67) for each SD increment of SBP recovery and DBP recovery for risk of hypertension. Additionally, results yielded HRS of 0.80 (95% CI, 0.69-0.93) for each SD increment in SBP recovery for CVD and 0.76 (95% CI, 0.65-0.88) for each SD increment in SBP recovery for all&#8208;cause mortality.

This study, “Association of Blood Pressure Responses to Submaximal Exercise in Midlife With the Incidence of Cardiovascular Outcomes and All&#8208;Cause Mortality: The Framingham Heart Study,” was published in the Journal of the American Heart Association.