lifestyle changes for prevention of hypertension

7/29/2019 Lifestyle changes for prevention of hypertension.

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Therapeutic role of exercisein treating hypertension


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Educational Objectives

To explain the acute blood pressureresponse to exercise

To list the mechanisms by which exercisemay improve hypertension

To apply exercise guidelines in treatinghypertension

To prescribe appropriate drug therapy foractive hypertensive patients


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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 highBP but because of their side effects andcost, non-pharmacologic alternatives areattractive


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Classification of Blood Pressure

Blood Pressure Category Systolic Diastolic

Optimal


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Pathophysiology of Hypertension

High blood pressure is also associated

with obesity, salt intake, low potassium

intake, physical inactivity, heavy alcoholuse and psychological stress

Intra-abdominal fat and hyperinsulinemia

may play a role in the pathogenesis ofhypertension


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Prevalence of Other RiskFactors With Hypertension

Risk Factor Percent

Smoking 35

LDL Cholesterol >140 mg/dl 40HDL Cholesterol < 40 mg/dl 25

Obesity 40

Diabetes 15Hyperinsulinemia 50

Sedentary lifestyle >50


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Cardiovascular Consequencesof Hypertension

Individuals with BP > 160/95 have CAD,PVD & stroke that is 3X higher than

normalHTN may lead to retinopathy and

nephropathy

HTN is also associated with subclinicalchanges in the brain and thickening andstiffening of small blood vessels


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Cardiovascular Consequences

of Hypertension

Increased cardiac afterload leads to leftventricular hypertrophy and reduced early

diastolic fillingIncreased LV mass is positively

associated with CV morbidity and mortalityindependent of other risk factors

High BP also promotes coronary arterycalcification, a predictor of sudden death


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Hypertension & CVD Outcomes

Increased BP has a positive andcontinuous association with CV events

Within DBP range of 70-110 mm Hg, thereis no threshold below which lower BPdoes not reduce stroke and CVD risk

A 15/6 mm Hg BP reduction reducedstroke by 34% and CHD by 19% over 5years


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Lifestyle Changesfor 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


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Blood Pressure classification

Blood PressureStage(mm Hg)

Risk Group ANo major risk factors

No TOD/CCD

Risk Group BAt least one major risk factor,

not including DM

No TOD/CCD

Risk Group CTOD/CCD and/or DM, with or

without other risk factors

High-Normal BP

130-139/85-89

Lifestyle

Modification

Lifestyle

Modification

Medication

Lifestyle

Modification

Stage 1 HTN

140-159/90-99

LifestyleModification

(up to 12 mo)

LifestyleModification

(up to 6 mo)

Medication

Lifestyle

Modification

Stage 2,3 HTN

160/100Medication

Lifestyle

Modification

Medication

Lifestyle

Modification

Medication

Lifestyle

Modification


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Medical Therapy andImplications for Exercise Training

Pharmacologic and nonpharmocologictreatment can reduce morbidity

Some antihypertensive agents have side-effects and some worsen other risk factors

Exercise and diet improve multiple riskfactors with virtually no side-effects

Exercise may reduce or eliminate theneed for antihypertensive medications


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Acute BP Response to Exercise


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Exaggerated BP Responseto Exercise

Among normotensive men who had an

exercise test between 1971-1982, those

who developed HTN in 1986 were 2.4times more likely to have had an

exaggerated BP response to exercise

Exaggerated BP response increasedfuture hypertension risk by 300% after

adjusting for all other risk factors


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Exaggerated BP Responseto 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 atany workload.

Subjects in CARDIA study with

exaggerated exercise BP were 1.7 timesmore likely to develop HTN 5 years later

J Clin Epidemiol 51 (1): 1998


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NIH Consensus Conference onPhysical Activity and CV Health (1995)

Review of 47 studies of exercise and HTN

70% of exercise groups decreased SBP by anavg. of 10.5 mm Hg from 154

78% of subjects decreased DBP by an avg. of8.6 mm Hg from 98

Only 1 study showed increased BP w/ EX

Beneficial responses are 80 times morefrequent than negative responsesHagberg, J., et.al., NIH, 1995: 69-71


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The Pedometer

a small device worn

at the waist that

counts steps

used successfully inobesity studies


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PA - A Fountain of YouthPhysical inactivity is a primary risk

factor

Harvard Study:


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Patient Education Tool


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Possible Mechanisms of BPReduction with Exercise

Reduced visceral fat independent of

changes in body weight or BMI

Altered renal function to increaseelimination of sodium leading to reduce

fluid volume

Anthropomorphic parameters may not beprimary mechansims in causing HTN


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Possible Mechanisms of BPReduction with Exercise

Lower cardiac output and peripheral

vascular resistance at rest and

submaximal exerciseDecreased HR

Decreased sympathetic and increased

parasympathetic tone

Lower blood catecholamines and plasma

renin activity


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Antihypertensive & Volume DepletingEffects of Mild Exercise on Essential HTN


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Exercise Prescriptions for Patients WithBorderline-to-Moderate Hypertension

Patient

evaluation

Look for lipid disorders, DM,

retinopathy, neuropathy, PVD,

renal insufficiency, LV

dysfunction, silent MI/ischemiaosteoarthritis, osteoporosis

Exercise testing GXT with modified Naughton

protocol, R/O asymptomatic

ischemic CAD, radionuclide

Exercise type Aerobic, low-impact activities:

walking, biking, swimming, tai

chi, stepper, treadmill walking


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Frequency 5 days/week as a minimum

Intensity Start at 50-60% maximum HRR &

slowly increase to 70%; within 6weeks work at 85% HRR or from

50-90% of maximal heart rate

Duration 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


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Excessive rises in blood pressure

should be avoided during exercise

(SBP > 230 mm Hg; DBP > 110 mmHg). Restrictions on participation in

vigorous exercise should be placed

on patients with left ventricularhypertrophy.


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Weight Training

Resistive exercise produces the most strikingincreases in BP

Resistive exercise results in less of a HR

increase compared with aerobic exercise and asa result the rate pressure product may be lessthan aerobic exercise

Assessment of BP response by handgrip shouldbe considered in patients w/ HTN

Growing evidence that resistive training may beof value for controlling BP


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Beta-blocker therapyand exercise

Non-selective Beta-blockers may increase

a patients disposition to exertional

hyperthermia. So patients should adherestrictly to guidelines for fluid replacement

Patients should use fluid replacement

drinks with low concentrations of K+

toavoid the risk of hypokalemiaGordon, N.F., Am J Cardiol 55: 74-78,1985


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SUMMARY

Physical activity has a therapeutic role inthe treatment of hypertension

No consistent relationship betweenreduced weight and lower BP

Exercise at lower intensities is effective intreating mild to moderate hypertension

Exercise testing may help identifyexaggerated BP responses to exercise


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SUMMARY

Exercise prescription for HTN should bebased on medical hx and risk factor status

Exercise prescription should be adaptedto antihypertensive medications that mayaffect exercise HR, BP & performance

Incorporating resistive training into the

exercise prescription may be of value forcontrolling blood pressure


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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.

lifestyle changes for prevention of hypertension

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