Effect of Exercise on Blood Pressure in Older Persons

1. Effect of Exercise on Blood Pressure in Older Persons • Stewart K, Bacher A, Turner K, et al. Effect of Exercise on Blood Pressure in Older Persons. Arch Intern Med. 2005;165:756-762. 53 controls, 51 exercisers, 8 dropouts/3 withdrawals- each completed 69 +/- 8 of 78 sessions Change from Baseline • Exercisers reduced SBP by 5.3 and DBP by 3.7 (DBP was significantly different with control group) • Controls significantly reduced SBP by 4.5 & DBP by 1.5 • Arterial stiffness did not significantly change Sex Differences • Men had greater total body strength increase than women & greater reductions in abdominal visceral fat Changes in habitual physical activity and diet • No significant difference of total daily energy expenditure for controls and exercisers Correlations to Changes in BP Background: Because of age-related differences in the cause of hypertension, it is uncertain whether current exercise guidelines for reducing BP are applicable to older persons. Few exercise studies in older persons have evaluated BP changes in relation to changes in body composition or fitness. Methods: This was a 6 month randomized controlled trial of combined aerobic and resistance training’ controls followed usual care physical activity and diet advice. Participants (aged 55-75) had untreated SBP of 130-159 mmHg or DBP of 85-99 mmHg Results: 51 exercisers and 53 controls completed the trial. Exercisers significantly improved aerobic and strength fitness, increased lean mass, and reduced general and abdominal obesity. Mean decreases in SBP and DBP, respectively, were 5.3 and 3.7 mmHg among exercisers and 4.5 and 1.5 mmHg among controls (P<.001 for all). There were no significant group differences in mean SBP change from baseline (-0.8 mmHg; P=.67). The mean DBP reduction was greater among exercisers (-2.2 mmHg; P=02). Aortic stiffness, indexed by aortofemoral pulse-wave velocity, was unchanged in both groups. Body composition improvements explained 8% of the SBP reduction (P=.006) and 17% of DBP reduction (P<.001). Conclusion: A 6 month program of aerobic and resistance training lowered DBP but not SBP in older adults with mild HTN more than in controls. The concomitant lack of improvement in aortic stiffness in exercise suggests that older persons may be resistant to exercise-induced reductions in SBP. Body composition improvements were associated with BP reductions and may be a pathway by which exercise training improves cardiovascular health in older men and women. Abstract Kerry Stewart, Anita Bacher, Katherine Turner, Jerome Fleg, Paul Hees, Edward Shapiro, Matthew Tayback, Pamela Ouyang Background Subjects • age 55-75 with untreated mild forms of hypertension Process • Blood pressure was taken 3 times for a screening, baseline, and 6 month average • Peak oxygen uptake and RPE were assessed while walking speed increased 3.5% every 3 minutes • Muscle strength, body composition, arterial stiffness, and total daily expenditure were assessed Exercise Intervention • 3 sessions per week consisting of a stretching warm-up, resistance training, then aerobic training Control Group • Participants given the National Institute on Aging guidelines for exercise and AHA Step 1 Diet • No additional advice was given Materials & Methods Clinical Significance Body composition had the strongest correlation with BP changes, rather than fitness. This suggests that changes in body composition are an important pathway for exercise to cause improvements in CV health in older men and women. Conclusion Presented By: Exercising has always been a common prescription to help lower blood pressure in younger people, but it is uncertain whether or not exercise has the same influence in older people with HTN in comparison to younger people due to the different causes of HTN. All 3 articles can be used in the clinic, as they all established that the effects of exercising in older individuals will help their CV health. However, between the 3 articles, the ways in which it was improved was inconclusive. The 2nd and 3rd article support a significant reduction in SBP and the original article stresses the importance of exercise on body composition to help improve CV health. Article 2 Evidence Huang G, Thompson C, Osness W. Influence of a 10-Week Controlled Exercise Program on Resting Blood Pressure in Sedentary Older Adults. The Journal of Applied Research. 2006; 6(3):188-195. • Subjects: 52 elderly patients randomly split into a control group and two exercising groups • Intervention: one group performed at moderate intensity and the other at high intensity 3 times a week for 40 minute sessions • Results: SBP significantly decreased in the high intensity exercising group and DBP significantly decreased in all 3 groups • Conclusion: training intensity determines effectiveness of short term exercise program on blood pressure • To get decrease in SBP need to exercise at a high intensity Westhoff T, Schmidt S, Gross V. The Cardiovascular Effects of Upper=Limb Aerobic Exercise in Hypertensive Patients. Journal of Hypertension. 2008:26(7):2-8. • Subjects: 24 elderly patients from hypertension outpatient clinic, split into control and exercising group • Intervention: participated in aerobic exercise with arm cycling device 3 times a week for 12 weeks • Results: SBP and DBP significantly decreased and small artery compliance improvement after 12 week exercise program • Conclusion: Upper-arm cycling is a good alternative to improve blood pressure control in the elderly if lower limb exercise is not an option. Both groups significantly reduced SBP, but only exercisers reduced DBP Considerations for smaller than expected SBP reduction: • As people aging arterial stiffness occurs from decreased elastic fibers, so exercise may not influence arterial stiffness • Older individuals may have a difficult time decreasing SBP because of arterial stiffness, despite improvements in fitness and fatness Considerations for change in control group • Controls were encouraged not to do anything beyond their normal, however research can motivate people to change Considerations for BP reduction in control groups • Placebo effect reduced the power of the study for group differences in change in BP Considerations for BP reductions correlated with other body composition & fitness changes • Reduction in abdominal subcutaneous fat was the strongest correlation with SBP change • Reduction in body weight, total fat, & increase in lean mass were the strongest correlation with DBP change • Mechanism for BP to be reduced is not fully known Does not strongly address relationship between BP and sex Strengths of Study • BP was measured with automated device • Participants had untreated HTN • Excellent attendance and adherence to exercise program Weakness: control group had reduction in SBP which reduced the power of the study Results Purpose Discussion Factors beyond exercise influence BP Aortic stiffness may prevent reduction of BP through exercise- due to the decrease in SBP in both exercisers and controls, but no significant difference in arterial stiffness. Overall BP changes correlated most to body comp changes Stephanie Smith, Bellarmine University Student PT Article 3 Evidence Summary Investigate how a 6 month exercising regimen can impact SBP and DBP in older individuals that are hypertensive, and how those changes in BP correlate to changes in body composition and fitness.