Chronic aerobic exercise improves blood pressure dipping status in African American nondippers

Abstract

Objective: The effects of exercise training on nocturnal blood pressure (BP) dipping status remain unclear. African Americans have the highest prevalence of nondippers compared with other racial/ethnic populations. In this 6-month study we tested the hypothesis that long-term aerobic exercise training would increase the levels of nocturnal BP dipping in African American nondippers.

Methods and results: We recruited African Americans who were nondiabetic, nonsmoking, and free from cardiovascular and renal disease. For this analysis, only African Americans with a nondipping profile, defined as those with the absence of a nocturnal decline in systolic or diastolic BP (<10% of daytime values), which was determined by ambulatory BP monitoring, were chosen. A pre-post design was used, with baseline and final evaluation including office blood pressure measurement, 24-h ambulatory blood pressure monitoring, fasted blood sampling, and graded exercise testing. Participants engaged in 6 months of supervised aerobic exercise training (AEXT). Following the AEXT intervention, there were significant increases in systolic BP dipping (baseline: 5.8±3.9% vs. final: 9.4±6.1%, P=0.0055) and pulse pressure dipping (baseline: -3.1±6.6% vs. final: 5.0±12.8%, P=0.0109). Of the 18 participants with a nondipping profile at baseline, eight were nonclassified as nondippers after the AEXT intervention. There were no significant changes in office systolic BP/diastolic BP values following the AEXT intervention.

Conclusion: This study suggests that the nondipping pattern of ambulatory BP can be improved by chronic AEXT in African American nondippers, regardless of a change in the 24-h average BP. This finding may be clinically important because of the target organ implication of nondipping nocturnal BP.

Conflict of interest statement

No conflicts of interest.

Figures

Figure 1

A: Systolic blood pressure dipping levels at baseline and final testing. The black bar represents the measurements at baseline, and the white bar represents the measurements at final test. Bars are expressed as mean ± SEM. *Denotes significantly different (p≤0.05). B: Diastolic blood pressure dipping levels at baseline and final testing. The black bar represents the measurements at baseline, and the white bar represents the measurements at final test. Bars are expressed as mean ± SEM.

Figure 1

A: Systolic blood pressure dipping levels at baseline and final testing. The black bar represents the measurements at baseline, and the white bar represents the measurements at final test. Bars are expressed as mean ± SEM. *Denotes significantly different (p≤0.05). B: Diastolic blood pressure dipping levels at baseline and final testing. The black bar represents the measurements at baseline, and the white bar represents the measurements at final test. Bars are expressed as mean ± SEM.

Figure 2

Night time (10: 00 PM to 6: 00 AM) hourly average systolic blood pressure at baseline and final testing. Open line represents the measurements at baseline, and the solid line represents the measurements at final test. Bars are expressed as mean ± SEM.