Transcript Therapeutic role of exercise in treating hypertension

Therapeutic role of exercise
in treating hypertension
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
Overview of Hypertension
High BP is a risk factor for stroke, CHF,
angina, renal failure, …
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
Classification of Blood Pressure
Blood Pressure Category
Optimal
Normal
High Normal
Hypertension
Stage 1 (Mild)
Stage 2 (Moderate)
Stage 3 (Severe)
Systolic
<120
<130
130-139
Diastolic
<80
<85
85-89
140-159
160-179
> 180
90-99
100-109
> 110
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
Prevalence of Other Risk
Factors With Hypertension
Risk Factor
Smoking
LDL Cholesterol >140 mg/dl
HDL Cholesterol < 40 mg/dl
Obesity
Diabetes
Hyperinsulinemia
Sedentary lifestyle
Percent
35
40
25
40
15
50
>50
Cardiovascular Consequences
of Hypertension
Individuals with BP > 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
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
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
Lifestyle Changes
for Hypertension
Reduce excess body weight
Reduce dietary sodium to < 2.4 gms/day
Maintain adequate dietary intake of potassium,
calcium and magnesium
Exercise moderately each day
Engage in meditation or relaxation daily
Cessation of smoking
Blood Pressure classification
Blood Pressure Risk Group A
No major risk factors
Stage (mm Hg)
No TOD/CCD
Risk Group B
Risk Group C
At least one major risk factor,
not including DM
No TOD/CCD
TOD/CCD and/or DM, with or
without other risk factors
High-Normal BP Lifestyle
Modification
130-139/85-89
Lifestyle
Modification
Medication
Stage 1 HTN
140-159/90-99
Lifestyle
Modification
(up to 12 mo)
Lifestyle
Modification
(up to 6 mo)
Medication
Stage 2,3 HTN
160/100
Medication
Medication
Medication
Lifestyle
Modification
Lifestyle
Modification
Lifestyle
Modification
Lifestyle
Modification
Lifestyle
Modification
Medical Therapy and
Implications for Exercise Training
Pharmacologic and nonpharmocologic
treatment can reduce morbidity
Some antihypertensive agents have sideeffects 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
Acute BP Response to Exercise
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
Exaggerated BP Response
to Exercise
Exaggerated BP was change from rest in
SBP >60 mm Hg at 6 METs; SBP > 70
mm Hg at 8 METs; DBP > 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
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
The Pedometer
a small device worn
at the waist that
counts steps
used successfully in
obesity studies
PA - A Fountain of Youth
Physical inactivity is a primary risk
factor
Harvard Study:
Patient Education Tool
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
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
Antihypertensive & Volume Depleting
Effects of Mild Exercise on Essential HTN
Exercise Prescriptions for Patients With
Borderline-to-Moderate Hypertension
Patient
evaluation
Exercise testing
Exercise type
Look for lipid disorders, DM,
retinopathy, neuropathy, PVD,
renal insufficiency, LV
dysfunction, silent MI/ischemia
osteoarthritis, osteoporosis
GXT with modified Naughton
protocol, R/O asymptomatic
ischemic CAD, radionuclide
Aerobic, low-impact activities:
walking, biking, swimming, tai
chi, stepper, treadmill walking
Exercise Prescriptions for Patients With
Borderline-to-Moderate Hypertension
Frequency
5 days/week as a minimum
Intensity
Start at 50-60% maximum HRR &
slowly increase to 70%; within 6
weeks work at 85% HRR or from
50-90% of maximal heart rate
Start with 20-30 min/day of
continuous activity for first 3 wk,
then 30-45 min/day for next 4-6
wk, and 60 min/day as
maintenance
Duration
Exercise Prescriptions for Patients With
Borderline-to-Moderate Hypertension
Excessive rises in blood pressure
should be avoided during exercise
(SBP > 230 mm Hg; DBP > 110 mm
Hg). Restrictions on participation in
vigorous exercise should be placed
on patients with left ventricular
hypertrophy.
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
Beta-blocker therapy
and exercise
Non-selective Beta-blockers may increase
a patient’s 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
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
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
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.
ACSM’s Resource Manual for Guidelines for Exercise Testing and
Prescription, Baltimore, Williams & Wilkins, p. 275-280, 1998.