Therapeutic role of exercise in treating hypertension

1
Therapeutic role of exercise in treating
hypertension

• Dalynn T. Badenhop, Ph.D., FACSM
• Professor of Medicine
• Director , Cardiac Rehabilitation
• Medical College of Ohio

2
Educational Objectives

• To explain the acute blood pressure response to
  exercise
• To list the mechanisms by which exercise may
  improve hypertension
• To apply exercise guidelines in treating
  hypertension
• To prescribe appropriate drug therapy for active
  hypertensive patients

3
Overview of Hypertension

• High BP is a risk factor for stroke, CHF, angina,
  renal failure, LVH and MI
• Hypertension clusters with hyperlipidemia,
  diabetes and obesity
• Drugs have been effective in treating high BP but
  because of their side effects and cost,
  non-pharmacologic alternatives are attractive

4
1997 JNC VI Classification of Blood Pressure
5
Overview of Hypertension

• Joint National Committee VI (JNC VI) on
  Prevention, Detection, Evaluation, and Treatment
  of High Blood Pressure (1997)
• 50 million hypertensive patients in the U.S.
• National Health and Nutrition Examination Survey
  III (NHANES III) (1995)
• only 21 of treated hypertensive patients have BP
  controlled to lt140/90 mm Hg
• 35 of hypertensive patients are unaware of their
  condition
• High-normal BP is associated with an incresed
  risk of cardiovascular disease
• N Eng J Med 2001 345 1291-7

6
Pathophysiology of Hypertension

• Essential hypertension is characterized by
  increased DBP and related arteriolar
  vasoconstriction leading to increased SBP
• BP is mainly determined by cardiac output and
  total peripheral resistance
• High blood pressure may be linked to age-related
  vascular stiffening

7
Pathophysiology of Hypertension

• High blood pressure is also associated with
  obesity, salt intake, low potassium intake,
  physical inactivity, heavy alcohol use and
  psychological stress
• Intra-abdominal fat and hyperinsulinemia may play
  a role in the pathogenesis of hypertension

8
Prevalence of Other Risk Factors With Hypertension
Kaplan NM. Dis Mon 1992 38769-838
9
Cardiovascular Consequences of Hypertension

• Individuals with BP gt 160/95 have CAD, PVD
  stroke that is 3X higher than normal
• HTN may lead to retinopathy and nephropathy
• HTN is also associated with subclinical changes
  in the brain and thickening and stiffening of
  small blood vessels

10
Cardiovascular Consequences of Hypertension

• Increased cardiac afterload leads to left
  ventricular hypertrophy and reduced early
  diastolic filling
• Increased LV mass is positively associated with
  CV morbidity and mortality independent of other
  risk factors
• High BP also promotes coronary artery
  calcification, a predictor of sudden death

11
Hypertension CVD Outcomes

• Increased BP has a positive and continuous
  association with CV events
• Within DBP range of 70-110 mm Hg, there is no
  threshold below which lower BP does not reduce
  stroke and CVD risk
• A 15/6 mm Hg BP reduction reduced stroke by 34
  and CHD by 19 over 5 years

12
Lifestyle Changes for Hypertension

• Reduce excess body weight
• Reduce dietary sodium to lt 2.4 gms/day
• Maintain adequate dietary intake of potassium,
  calcium and magnesium
• Limit daily alcohol consumption to lt 2 oz. of
  whiskey, 10 oz. of wine, 24 oz. of beer
• Exercise moderately each day
• Engage in meditation or relaxation daily
• Cessation of smoking

13
JNC VI Blood Pressure Classification
14
Medical Therapy and Implications for Exercise
Training

• Pharmacologic and nonpharmocologic treatment can
  reduce morbidity
• Some antihypertensive agents have side-effects
  and some worsen other risk factors
• Exercise and diet improve multiple risk factors
  with virtually no side-effects
• Exercise may reduce or eliminate the need for
  antihypertensive medications

15
Acute BP Response to Exercise
16
Exaggerated BP Response to Exercise

• Among normotensive men who had an exercise test
  between 1971-1982, those who developed HTN in
  1986 were 2.4 times more likely to have had an
  exaggerated BP response to exercise
• Exaggerated BP response increased future
  hypertension risk by 300 after adjusting for all
  other risk factors

17
Exaggerated BP Response to Exercise

• Exaggerated BP was change from rest in SBP gt60 mm
  Hg at 6 METs SBP gt 70 mm Hg at 8 METs DBP gt 10
  mm Hg at any workload.
• Subjects in CARDIA study with exaggerated
  exercise BP were 1.7 times more likely to develop
  HTN 5 years later
• J Clin Epidemiol 51 (1) 1998

18
NIH Consensus Conference on Physical Activity and
CV Health (1995)

• Review of 47 studies of exercise and HTN
• 70 of exercise groups decreased SBP by an avg.
  of 10.5 mm Hg from 154
• 78 of subjects decreased DBP by an avg. of 8.6
  mm Hg from 98
• Only 1 study showed increased BP w/ EX
• Beneficial responses are 80 times more frequent
  than negative responses
• Hagberg, J., et.al., NIH, 1995 69-71

19
Increasing Lifestyle Activity for Patients with
High-Normal Blood Pressure and Stage I
Hypertension

• Medical College of Ohio Study Group
• Kevin A. Phelps, D.O.
• Larry Johnson, M.D.
• Sandra Puczynski, Ph.D.
• Dalynn Badenhop, Ph.D.
• Michael McCrea
• Wendy Boone, RN, M.P.H

20
Lifestyle Activity vs.Structured Exercise

• JAMA 1999 281(4) 327-334
• moderate-intensity lifestyle activity showed
  similar or better results versus structured
  exercise for
• improved cardiovascular fitness
• reduced body fat
• decreased total cholesterol
• reduced blood pressure
• patient compliance
• In the past five years the Surgeon General, CDC,
  NIH, and ACSM have published position statements
  on the potential health benefits of lifestyle
  activity

21
Study Design

• Twenty-four week, physician-directed intervention
  program to lower BP by increasing physical
  activity
• Patients randomized into two groups
• Group 1 - educational intervention monitored via
  activity logs
• Group 2 - educational intervention monitored via
  activity logs and pedometer

22
The Pedometer

• a small device worn at the waist that counts
  steps
• used successfully in obesity studies

23
Study Hypotheses

• Adding a pedometer
• to goal setting will increase the level and
  frequency of physical activity
• will improve BP control of adult patients with
  high-normal BP or Stage 1 HTN

24
Main Outcome Measures

• Blood Pressure and BMI
• Physical Activity assessed by
• two questionnaires
• Physical Activity Recall Scale (PASE)
• assessed activity in past seven days
• Physician-based Assessment and Counseling for
  Exercise (PACE)
• assessed readiness for change in level of
  physical activity

25
Patient Education Tool
26
Methods Patient Identification

• Potential subjects identified by chart audit
• average BP of past three visits in High Normal BP
  or Stage 1 HTN category
• Exclusion Criteria
• Antihypertensive med use
• confirmed BP ³160/100
• Dx DM, CHF, CAD, CVD, CA, MR
• pregnant
• child (lt 18 yrs)

27
Methods Patient Recruitment

• Identified subjects contacted during regularly
  scheduled physician visit
• Physician introduced study to patient
• Interested patients met with research assistant
  for more information about study

28
Methods Patient Eligibility

• Interested patients had two eligibility visits
  two weeks apart to confirm elevated BP
• If average BP at two visits confirmed
  High-Normal BP or Stage 1 HTN from chart audit,
  then patient was scheduled for first study visit
  (t0)

29
Sample Characteristics
30
Methods Study Visits

• Research Assistant
• measured BP and weight, reviewed activity log at
  all visits
• administered PASE and PACE at baseline and
  completion
• Physician
• discussed barriers to increasing activity
• new activity goal setting
• assisted with problem solving

31
Preliminary Results

• Outcome measures analyzed at
• beginning of study, week 0 (t0)
• end of intervention period, week 12 (t1)
• end of maintenance period, week 24 (t2)

32
Change in Systolic BP from Time 0 to Time 1 (12
weeks) for both groups
P .005
33
Change in Systolic BP across time for both groups
(24 weeks)
34
Change in Diastolic BP from Time 0 to Time 1 for
both groups (12 weeks)
35
Change in Diastolic BP across time for both
groups (24 weeks)
36
Change in BMI across time for both groups (24
weeks)
37
Change in PASE across time for both groups (24
weeks)
38
Preliminary Conclusions

• Intervention alone (Group 1) did not
  significantly improve BP
• Intervention plus a pedometer (Group 2)
  significantly improved BP, but only with regular
  physician visits

39
Possible Mechanisms of BP Reduction with Exercise

• Reduced visceral fat independent of changes in
  body weight or BMI
• Altered renal function to increase elimination of
  sodium leading to reduce fluid volume
• Anthropomorphic parameters may not be primary
  mechansims in causing HTN

40
Possible Mechanisms of BP Reduction with Exercise

• Lower cardiac output and peripheral vascular
  resistance at rest and submaximal exercise
• Decreased HR
• Decreased sympathetic and increased
  parasympathetic tone
• Lower blood catecholamines and plasma renin
  activity

41
Antihypertensive Volume Depleting Effects of
Mild Exercise on Essential HTN

• 20 subjects with HTN (155/100) randomized to
  Exercise or Control group
• Cycle Ergometer Exercise at Blood Lactic Acid
  Threshold for 60 min. 3X/wk for 10 weeks
• Changes in BP, hemodynamics and humoral factors
  of EX group compared with control group
• Urata, H., et. al. Hypertension 9245-252,1987

42
Antihypertensive Volume Depleting Effects of
Mild Exercise on Essential HTN
43
Antihypertensive Volume Depleting Effects of
Mild Exercise on Essential HTN

• Whole blood and plasma volume indices were
  significantly reduced (p lt 0.05)
• Change in serum Naserum K positively
  correlated with change in SBP
• Plasma NE concentrations at rest Workload _at_
  BLAT during GXTs were reduced
• Change in resting NE correlated with change in
  mean BP
• Urata, H., et. al. Hypertension 9245-252, 1987

44
Changes in Taurine other Amino Acids in
Response to Mild Exercise

• Blood pressures were significantly decreased by
  14.8/6.6 mmHg in the EX group but not the Control
  group
• Serum concentration increases of taurine (26),
  cystine (287), asparagine (11), histidine (6)
  and lysine (7) in the EX
• Serum taurine was negatively correlated with the
  change in plasma NE
• Tanabe, Y, et. al., Clin Exper Hyper
  11149-165, 1989

45
Changes in Taurine other Amino Acids in
Response to Mild Exercise
46
(No Transcript)
47
Exercise Prescriptions for Patients With
Borderline-to-Moderate Hypertension
48
Modified Naughton Treadmill Protocol
49
Exercise Prescriptions for Patients With
Borderline-to-Moderate Hypertension
50
Exercise Prescriptions for Patients With
Borderline-to-Moderate Hypertension

• Excessive rises in blood pressure should be
  avoided during exercise (SBP gt 230 mm Hg DBP gt
  110 mm Hg). Restrictions on participation in
  vigorous exercise should be placed on patients
  with left ventricular hypertrophy.

51
Weight Training

• Resistive exercise produces the most striking
  increases in BP
• Resistive exercise results in less of a HR
  increase compared with aerobic exercise and as a
  result the rate pressure product may be less
  than aerobic exercise
• Assessment of BP response by handgrip should be
  considered in patients w/ HTN
• Growing evidence that resistive training may be
  of value for controlling BP Kelemen, et.al., JAMA
  2632766-71,1990

52
Drug Therapy for Active Hypertensive Patients

• Hypertension only
• Thiazide diuretics in combination with a
  potassium supplement are effective and
  inexpensive
• Diuretics limit plasma volume expansion and
  decrease peripheral resistance
• Other antihypertensive drugs can be used as
  monotherapy for this type of patient

53
Drug Therapy for Active Hypertensive Patients

• Hypertension with other diseases
• CAD - calcium-channel blocker or a beta-
  blocker
• Diabetes - ACE inhibitor
• LVH but coughs with ACE inhibitor -
  angiotensin-2-receptor blocker
• Elderly men with prostatism - peripheral
  alpha-blocker (terazosin, doxazosin)

54
Drug Therapy for Active Hypertensive Patients

• Beta1-selective blockers such as atenolol or
  metoprolol are preferable to non-selective agents
  such as propranolol, nadolol or pindolol for
  hypertensive patients engaged in regular exercise
  
• Kaplan, N.M., Am J Hypertens 275-77,1989

55
Beta-blocker therapy and exercise

• Non-selective Beta-blockers may increase a
  patients disposition to exertional hyperthermia.
  So patients should adhere strictly to guidelines
  for fluid replacement
• Patients should use fluid replacement drinks with
  low concentrations of K to avoid the risk of
  hypokalemia
• Gordon, N.F., Am J Cardiol 55 74-78,1985

56
Beta-blocker therapy and exercise

• Exercise therapy is desirable during Beta-blocker
  therapy to offset the adverse alterations in
  lipoprotein metabolism contributed by some
  Beta-blocker medications
• Gordon, N.F., Compr Ther 14 52-57, 1988

57
Beta-blocker therapy and exercise

• Exercise intensity for patients on Beta-blocker
  medications should be in accordance with
  traditional guidelines based on the results of
  individualized exercise testing performed on the
  medication.
• American College of Sports Medicine
• Guidelines for Exercise Testing and Prescription,
  2000

58
Beta-blocker therapy and exercise

• Non-selective Beta-blockers dramatically reduce
  peak aerobic capacity and at the same time
  increase a patients rating of perceived exertion
  for a given amount of work.
• Kaplan, N.M., Am J Hypertens 275-77,1989

59
Beta-blocker therapy and exercise

• Patients treated with Beta-blockers are capable
  of deriving the expected enhancement of
  cardiorespiratory fitness during training,
  irrespective of the type of drug used
• Blood, S.M., J Cardiopulmonary Rehabil 8
  141-144, 1988

60
SUMMARY

• Physical activity has a therapeutic role in the
  treatment of hypertension
• No consistent relationship between reduced weight
  and lower BP
• Exercise at lower intensities is effective in
  treating mild to moderate hypertension
• Exercise testing may help identify exaggerated BP
  responses to exercise

61
SUMMARY

• Exercise prescription for HTN should be based on
  medical hx and risk factor status
• Exercise prescription should be adapted to
  antihypertensive medications that may affect
  exercise HR, BP performance
• Incorporating resistive training into the
  exercise prescription may be of value for
  controlling blood pressure

62
References

• Chintanadilok, J., Exercise in Treating
  Hypertension, PhysSports Med 30 11-23, 2002
• Urata, H., Antihypertensive and Volume-Depleting
  Effects of Mild Exercise on Essential
  Hypertension, Hypertension 9 245-52, 1987.
• Tanabe, Y., Changes in Serum Concentration of
  Taurine and Other Amino Acids in Clinical
  Antihypertensive Exercise Therapy, Clin and Exper
  Hyper A11 149-165, 1989.
• American College of Sports Medicine, Physical
  Activity, Physical Fitness and Hypertension, Med
  Sci Sports Exerc 25 i - x , 1993.
• ACSMs Resource Manual for Guidelines for
  Exercise Testing and Prescription, Baltimore,
  Williams Wilkins, p. 275-280, 1998.