Aging, Exercise, And CV Health

Aging, Exercise, and Cardiovascular HealthPkamalanathanAssociate professor of physiotherapySRM UNIVERSITY

Exercise and HealthExercise and AgingExercise and disease preventionCHDDiabetesCancerStroke

Exercise and Aging7-8% of adults: regular vigorous exercise32-36% of adults: Regular low intensity exercise (lower than recommended)Exercise incidence typically w/ age* More than half of individuals who begin regular exercise program quit within first 6 monthsCenters for Disease Control

Exercise and AgingFunctional capacity peaks between 20 and 30 years of age and decreases with advancing years.Active people show 25% higher functional capacity at any age over sedentary counterparts!Physical capacity will decline w/ age, but older people can still improve!

Exercise and AgingMuscular StrengthPeaks between 20 & 30 and declines approximately 30% by age 70Due to reduced muscle mass (likely an actual loss of fibers)Muscles are still trainableST decreases muscle protein lossGains in strength (%) in elderly are similar to those seen in the youngIncreases and maintains flexibility

Exercise and AgingNervous System37% decline in spinal cord axons10% decline in conduction velocityLoss of elasticity of connective tissueDecreased RT and muscle contraction velocityMinimized by exercisePulmonary FunctionOlder, endurance trained individuals score significantly higher on PFTs

Exercise and AgingCardiovascular FunctionAerobic capacity decreases 35% by age 65Hrmax declines with age (220-age)SV decreases*Reduction of blood flow due to stenosis (Heart?)Decreased elasticity of major vessels

Exercise and AgingCardiovascular System Responds to Training at any AGE!!!Adaptations (%) similar to those seen in younger individuals.Decline may be 2Xs faster however.Body CompositionExercise diminishes increase in BF% seen with aging

Aging vs. Sedentary LifestyleAging and being sedentary combined, facilitates loss of physical capacity.Many people blame getting old for everything (usually lack of activity).Human body improves with activity...REGARDLESS OF AGE!!!

Exercise to Improve Health and Extend LifeHarvard Alumni Study (Classes of 1920 - 1954)Exercise improved health and reduced mortalityHypertensives: Reduced death rate by 50%Individuals with parents who died prior to age 65: Reduced death rate by 25%

Harvard Alumni Study

Exercise to Improve Health and Extend LifeEpidemiological evidenceStudies have shown a cause - effect relationship between physical inactivity and CHD (sedentary person = 2Xs risk)Protective association just as strong as hypertension, smoking, and high cholesterol.Physical inactivity is the GREATEST risk factor for heart disease...more people are physically inactive than possess ALL other CHD risk factors!

Light Activity is ValuableLowHigh

Cardiovascular DiseasesCardiovascular diseases including: Coronary Artery Disease (CAD) or Coronary Heart Disease (CHD), are the leading killer of Americans.

Cardiovascular disease includes all diseases associated with the heart and / or blood vessels.

Cardiovascular DiseasesCardiovascular diseases can lead to myocardial infarction (heart attack), stroke, embolisms, aneurysms, etc.Incidence of deaths from heart disease have declined since 1970 (due to advances in technology, not decrease in CHD incidence)Annual costs over 120 billion dollars!

Cause of Death in the USA

Coronary Artery Disease (CAD)Coronary circulationALL blood supplied to heart is done so via two coronary arteries (Right & Left) that bifurcate from the aorta just above the LV.There is absolutely NO blood perfusion from inside the chambers of the heart.If coronary artery is blocked, the heart may be starving for O2 all the while it is full of oxygenated blood.

1.) Right Coronary artery2.) Left Coronary Artery

Coronary Artery Disease (CAD)Degenerative changes involving the lining of major vessels supplying blood to the heart.Various compounds interact with these changes (injured areas) including the oxidative reaction of LDL-C to form a fatty streak.This is the first sign of atherosclerosis.Eventually a plaque is formed and the body will respond by generating scar tissue.

Coronary Artery Disease (CAD)All of these lead to a narrowing of the CA.Eventually causes the myocardium (heart muscle) to become ischemic, or poorly supplied with oxygenOften associated with angina or chest pains.Blood flow may become very slow and turbulent causing development of a clot or thrombus.

Myocardial InfarctionMyocardial Infarction:The result of inadequate perfusion of blood in the coronary arteries. Caused by a significant reduction in the diameter of the vessel (most often caused by a thrombus).Many people suffer MIs without ANY prior symptoms! Mortality rate decreases in individuals who are exercise trained.

Symptoms Suggestive of CADPain or discomfort in chest, jaw, or arm*Shortness of breath*Dizziness*Orthopnea (diff. Breathing when supine)Ankle edema (chronic)Claudication*Unusual fatigue or dyspnea with light activity

*Usually,but not always experienced during exertion

CAD Begins EarlyFatty streaks are common in children as young as 5 yrs.Studies examining autopsy results of Vietnam casualties (avg. age 19 yrs.) showed significant CAD in majority of men.

Risk Factors for CADModifiableObesitySedentary lifeBlood lipidsDietHypertensionSmokingDiabetesTension & stressEducationNon-ModifiableGENETICS *Family History*RaceSex

Age

Modifiable Risk FactorsMinimizing modifiable risk factors is our best defense against developing CAD!

It is impossible to weight various risk factors, because of the role of genetics. Some people simply dont develop heart disease because of the presence of a certain risk factor, when some one else may.

Modifiable Risk FactorsPrimary Risk FactorsLipid levels (cholesterol)Blood pressureSmokingPhysical Inactivity

Modifiable Risk FactorsBlood lipid abnormalitiesActual mechanism is not yet fully understoodHowever, strong statistical link with TC, LDL-C, & HDL-C and incidence of CAD.TC < 200 mg/dLLDL-C < 130 mg/dLHDL-C > 35 mg/dLTG < 135 mg/dL (males) 160 mg/dL (females)

Modifying Blood Lipid LevelsFavorable EffectsWeight lossExerciseHigh water-soluble fiber intakeHigh polyunsat. saturated fat ratioIntake of omega-3 fatty acids (fish)Moderate alcohol consumption

Unfavorable EffectsSmokingDiet high in saturated fat and cholesterolStressOral contraceptivesSedentary lifestyle

Modifying Blood Lipid LevelsBlood lipids are still very dependant on a persons genetic makeup!Some people respond to diet and exercise, some require medication.Lowering elevated lipids is extremely important for minimizing CAD risk!

HypertensionElevated blood pressure may be caused by several things; HTN is result of either:Excessive vasoconstrictor tone*Arteriosclerosis: hardening of arteriesHigh blood volume

HypertensionHigh blood pressure is defined as resting systolic > 140 mm/Hg and/or diastolic > 90 mm/Hg.Incidence increases with:Family historyHigh Na+ intakeStressObesityKidney ailmentsSmoking

HypertensionOften called silent killerMost people do not know they have it90% of causes are of unknown etiology (essential hypertension)Uncorrected, HT can lead to heart failure, heart attack, stroke, and kidney failure.Exercise is often the best way lower borderline hypertension.

SmokingIncreases CAD risk 2X & stroke risk 5X.Smoking has negative effect on blood lipids and increases incidence of hypertension.Each cigarette smoked equates to a loss of seven minutes of life Americans loose 5 million years of potential life annually to smoking!

Physical InactivityExercise protects against CAD by:Normalizing blood lipid profile (increased HDL-C and lowered LDL-C)Lowered blood pressure and HRrest (less physical demand / work on myocardium)Improving myocardial circulation and metabolism (protects heart during hypoxic stress)Increased vascularizationIncreased glycogen stores and anaerobic capacity

Physical InactivityExercise protects against CAD by:Increased myocardial contractility & vascularizationDeveloping a more favorable body compositionDecreases clot formationReduces stress and tension

ObesityDetermining importance of obesity as a risk factor is difficult since it is almost always seen in conjunction with other risk factors.Overweight (>30% BF) see a 70% increased mortality risk.Increased risk of CAD, diabetes, and stroke.

DiabetesHigh blood glucose levels increase degeneration seen in vessels.Diabetics often have circulatory problems throughout the body.High blood sugar levels will irritate plaques in CA and increase likely hood of them enlarging and/or developing clots

Diabetes and ExerciseMost diabetics are Type II, adult onset.Exercise and obesity are the two largest risk factors for Type II diabetes.Most often caused by insulin receptor insensitivity (brought on by huge fluctuations in blood sugar)Most Type II diabetics can control blood glucose with diet and exercise and can often live completely free of insulin therapy.

Stress, Tension, & Type AsIncreased incidence of CAD is seen in individuals with high levels of stress, self reported tension, or who are classified as Type A personalities.

RELAX!

Non-modifiable Risk FactorsFamily History: Likely the most POTENT risk factor!Age: Incidence increases with age.Sex: Females have less CAD at any given age than male counterparts. (Protective mechanisms of estrogen)Race: Different races show different CAD rates (Genetics, diet, and lifestyle)

Risk Factors (Summary)Physical InactivityDiet high in fat and cholesterolSmokingHigh BF% (Obesity)DiabetesStress and tension

Interaction of Risk Factors