Transcript Metabolic syndrome - Helderberg Cardiac

Cardiovascular disease and
its syndromes: Why exercise?
METABOLIC SYNDROME:
What is it?
• A condition in which several coronary heart disease risk
factors are grouped together
• According to ACSM: Diagnosis is made when 3 or more
of the risk determinants are present
• Abdominal obesity – a central feature of this syndrome
Risk factors of metabolic
syndrome
Risk factor
Abdominal obesity
Men:
Women:
Defining level
>102 cm
>88cm
Triglycerides
≥150mg/dL
HDL cholesterol
<1.03mmol/dL
Blood pressure
≥130/85
Fasting glucose
≥110mg/dL
Risk factor 1: Obesity
• According to WHO:
– 29% men and
– 56% women in South Africa are overweight or
obese
– Much higher than other African countries
– 1.3 billion people worldwide
Risk factor 1: Obesity
• Can be caused by interplay between genetic and
environmental factors.
• In the end: A positive energy balance = obesity
↓
calories consumed is greater than calories used
• Abdominal fat or apple-shaped body type = highest risk
Determining obesity: BMI
WEIGHT CLASS
BMI (body mass index)
Underweight
<18.5
Normal
18.5-24.9
Overweight
25.0-29.9
Obesity:
Class 1
30.0-34.9
Class 2
35.0-39.9
Class 3
≥40
Problem with BMI
• Does not take muscle mass or bone density into
consideration
• Study was done on women with a BMI near 30: Still not
of major concern if weight is distributed in the pelvis and
not the abdomen
• When trying to lose weight: A decrease in body weight
due to a loss of skeletal muscle or bone mass – does not
improve a person’s risk levels for cardiovascular
diseases.
• Rather use ‘Waist-to-hip ratio’
Waist-to-hip ratio
• Circumference of waist ∕ circumference of hips
• How to measure:
Waist: Abdomen relaxed, horizontal measure at
narrowest part of torso
Hip: Horizontal measure at maximal circumference of
buttocks
• Risk stratification:
• For people 60yrs and older high risk =
•
Men: WHR > 1.03
•
Women: WHR > 0.90
Exercise and obesity
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Many weight loss programmes available.
Key components:
1.
2.
GRADUAL weight loss of 0.5 to 1kg per week.
More emphasis placed on frequency and duration,
rather than intensity of exercise
Primary mode should be large muscle group aerobic
activities
However, combine with resistance exercise
3.
4.
Exercise and obesity
• NB not to lose hope if weight reduction is minimal:
• According to research, it is not necessary to achieve an
OPTIMAL body weight to experience the health benefits.
• Even slight levels of weight loss ( 5 – 10% reduction in
body weight) results in:
1. Significant reductions in blood pressure
2. Increases in insulin sensitivity
3. Improvements in lipid concentrations
Risk factor 2: Insulin resistance
• In a normal person: Stomach breaks down sugars into
glucose which then enters the bloodstream
• Insulin is secreted by the pancreas
• Insulin binds to glucose and allows it to enter cells
throughout the body
Insulin resistance
• Insulin resistance occurs when the body cells no longer responds to
insulin
• Pancreas reacts by producing more insulin – hyperinsulinemia –
causing other problems such as making it difficult for the body to use
stored fat for energy
• Glucose is therefore not taken up by the cells and remains in the
bloodstream
Insulin resistance: Causes
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Genetics
Lack of physical activity
Obesity
Pregnancy
Infection or severe illness
Stress
Prolonged steroid use
Insulin resistance and exercise
• Exercise assists with glucose control since it has an
insulin-like effect
• Enhances glucose uptake even when insulin levels are
low
• Increases insulin sensitivity
• Decreased insulin requirements
Risk factor 3: High blood
pressure
Blood pressure
classification
Systolic blood
pressure
(mmHg)
Normal
<120
Diastolic blood
pressure
(mmHg)
And
<80
Pre-hypertension 120-139
Or
80-90
Stage 1
Hypertension
Stage 2
Hypertension
140-159
Or
90-99
≥160
Or
≥100
Blood pressure=silent killer
• The relationship between blood pressure and the risk of
developing cardiovascular disease is continuous,
consistent and independent of other risk factors.
• For people aged 40 – 70yrs: Each increase of 20mmHg
in systolic BP or 10mmHg in diastolic BP, the risk of
cardiovascular disease or having another cardiovascular
event …. DOUBLES
Blood pressure and exercise
* Aerobic exercise has an impressive blood pressure
reduction effect: 3.84mmHg for systolic BP
2.58mmHg for diastolic BP
• Studies show:
• Mean blood pressure reduction is not significantly linked
to mean change in body weight – instead blood pressure
will lower even in people who did not lose weight at all.
• The blood pressure reduction is also not directly linked to
frequency or intensity of aerobic exercise, therefore all
forms of exercise seems to be effective in lowering blood
pressure
Risk factor 4: Low HDL &
exercise
• Low HDL levels are strongly related to risk for
cardiovascular diseases
• For every 1ml/dl decrease in HDL-cholesterol, the risk
for CAD increases by 2 – 3%
• Most research studies are consistent:
• HDL levels in endurance athletes are 20 to 30% higher
than in sedentary individuals
HDL & exercise
• If there is no significant change in body weight and
composition, increased exercise has little effect on HDL
levels
• THEREFORE:
• If the exercise programme is prolonged and there is
associated weight loss, loss of body fat and increased
muscle mass, HDL levels can rise significantly.
Risk factor 5: High triglycerides
• What are triglycerides?
• The most common form of fat which are the main
ingredient in vegetable oils and animal fats
• The body uses it for energy, however if triglyceride levels
are elevated, even with no other risk factors = at risk for
CAD
Causes of high triglycerides:
• Lifestyle factors: overweight, inactivity, smoking,
excessive alcohol use, eating a high carbohydrate diet
• Certain medications: Corticosteroids, estrogens,
retinoids( used to treat acne, etc), high doses of betaadrenergic blocking agents
• Certain conditions: Type 2 diabetes, some kidney
diseases, hereditary factors.
Exercise and triglycerides
• Study showed: Aerobic exercise training in the presence
or absence of weight loss reduces fasting and
postprandial triglycerides.
• Sessions of low-to-moderate intensity aerobic exercise
of about 30-90 min decreased postprandial triglyceride
levels by 15 – 50%.
I had a Cardiac event: How do I
exercise?
Component of Frequency
fitness
Intensity
Time
Cardiovascular Minimum of
3 times per
week
60-75% of
20-60min
HR max
40-60%
HRR
RPE: 12-15
Aerobic
Muscle
strength
2-3 times
per week
To
moderate
fatigue
8-10 different
exercises
involving
major muscle
groups
Flexibility
Minimum of Stretch to
Hold 152-3 days per tightness
30sec, 2-3
week
but not pain times
One set of
10-15 reps
Type
Static
stretching
Calculating your heart rate at
which you should exercise
• Heart rate reserve:
• Step 1: HRR = Maximum heart rate – resting heart rate
• (If you do not know your maximum heart rate, use 220age)
• Step 2: Training intensity is selected: 40-60%
• Step 3: Add resting heart rate
• NB: If you are on a beta-blocker, you must subtract 2030 beats from the first step eg. 220-age-30
Example of calculating your
heart rate
• Tom is a 70 year old man who had a heart attack in February 2011.
He is keen to start a healthy lifestyle beginning with exercise. He has
a resting pulse of 84. His Biokineticist worked out his heart rate
reserve
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Maximum heart rate: 220 – 70 = 150
Max HR – Resting HR: 150 – 84 = 66
40% of above: 0.4 x 66 = 26.4
60% of above: 0.6 x 66 = 39.6
Add Heart rate rest: 26.4 + 84 = 110
39.6 + 84 = 123.6
• Therefore, Tom should exercise between 110 and 124 beats per
minute
RPE scale
• This is a scale of an individual’s subjective perception of effort
• Borg RPE scale: Ranges from 6 – 20
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6 = No exertion at all
7-8 = Extremely light
9-10 = Very light
11-12= Light
12-13 = Somewhat hard
14-16 = Hard
17-18 = Very hard
19 = Extremely hard
20 = Maximal exertion
RPE should not be used individually if you are not 100% sure that you
can reliably match your perceived exercise intensity to objective
measures such as HR.
Warm-up and cool down
• Very important for starting and ending exercise
programmes.
• Why the warm-up is important:
• 1. It raises the pulse rate in a graduating and safe way,
thereby preparing the body
• 2. Redistributes blood to active tissues.
• 3. Increases muscle temperature which may speed the
muscle action & relaxation.
• 4. Stimulates the release of synovial fluid
Cool down
• Should have at least 10min of cool down in which
exercises of reduced intensity and passive stretches are
incorporated
• The cool down:
• Reduces the risk of hypotension after an exercise
session
• Helps the heart rate to gradually return to resting levels
• Allows circulating catecholamines (which increases the
risk of arrhythmias following exercise) to drop to resting
levels
• After the cool-down the heart rate should have dropped
to 10 beats per minute of resting levels
Let’s get … MOVING!!