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Clinical Care
Part III
Atherosclerotic Cardiovascular Disease (ASCVD)
The presence of the metabolic syndrome raises the lifetime risk for both
ASCVD and type 2 diabetes (T2DM). Average relative risks are increased
about twofold for ASCVD and fivefold for T2DM compared with those for
individuals without the metabolic syndrome. The risk for ASCVD is significantly
more in those people with the metabolic syndrome who already have T2DM.
At the same time, the metabolic factors utilized in making the diagnosis
of the metabolic syndrome do not take into account all the known risk
factors leading especially to ASCVD.
Table
The risk factors for premature atherosclerotic cardiovascular disease
(ASCVD) are:
Non-Modifiable Risk factors
Genetic factors (family history of premature CAD in first degree relative:
male < 55years and female <65 years old) The closeness of the
relationships (eg, CHD in a sibling or parent confers greater risk
than CHD in an uncle)
Age of the patient ( >45 years in men and > 55 years in women)
Male Sex |
Modifiable Risk factors
Lifestyle risk factors
Obesity, especially central or visceral obesity
Atherogenic diet
Physical inactivity
Smoking |
Metabolic Risk Factors
Atherogenic dyslipidemia (elevations of lipoproteins containing apolipoprotein
B, elevated triglycerides, increased small particles of LDL, and low
levels of high- density lipoproteins (HDL), Elevated lipoprotein(a)
Elevated LDL-Cholesterol levels
Elevated blood pressure systolic and/or diastolic,
Elevated plasma glucose,
A prothrombotic state, and
A proinflammatory state: Markers of inflammation, such as hs-CRP
Elevated homocysteine. |
"BASIC SCREEN" for risk factors is practically the same
as one would undertake for a person with diabetes.
Further investigation would depend on individual circumstances, availability
and degree of clinical suspicion.
The metabolic syndrome is a simple clinical tool to identify people with
a particular set of risk factors who are at higher life time risk for
both ASCVD and type 2 diabetes.
All patients with the metabolic syndrome must be offered
1) lifestyle intervention (weight loss, increased physical activity, and
a healthy diet) and
2) more detailed, short-term risk assessment (e.g., Framingham scoring).
For management of long-term as well as short-term risk, lifestyle therapies
are first-line interventions to reduce the metabolic risk factors. The
major lifestyle interventions include weight loss in overweight or obese
subjects, increased physical activity, and modification of an atherogenic
diet. These changes will produce a reduction in all of the metabolic risk
factors simultaneously. In the long run, the greatest benefit for those
with the metabolic syndrome will be derived from effective lifestyle intervention.
For metabolic syndrome patients without ASCVD or diabetes, Framingham
risk (or similar validated risk) scoring should be performed to estimate
10-year risk for coronary heart disease (CHD). This assessment triages
patients into 3 risk categories based on 10-year risk for CHD: high risk
(10-year risk >20%), moderately high risk(10-year risk 10% to 20%),
or lower to moderate risk (10-year risk <10%).
For the Framingham Point Score Tables see Appendix 16a
People with diabetes and ASCVD are always considered to be in the
high risk category.
CHD risk is also higher than indicated in the charts for:
Those with a family history of premature CHD (male
first degree relatives aged <55 years and female first degree relatives
aged <65 years) which increases the risk by a factor of approximately
1.5
Those with raised triglyceride levels and other dyslipidemias.
Women with premature menopause.
Those who are not yet diabetic, but have IFG or IGT, or both.
Patients with Type 1 diabetes.
Patients with type 2 diabetes
Moreover, in ethnic minorities the risk charts should be used with
caution because they have not been validated in these populations.
For example, in people originating from the Indian subcontinent it
is safest to assume that the risk is higher than predicted from the
charts. |
High-risk patients have established atherosclerotic CVD, diabetes, or
10-year risk for CHD >20%. For cerebrovascular disease, high-risk conditions
include TIA or stroke of carotid origin or >50% carotid stenosis.
All high and moderately high 10 year risk patients merit intensive and
specific management of all metabolic risk factors as well as T2DM if present.
No specific drugs are currently recommended for people with the metabolic
syndrome independent of those agents most appropriate for specific, abnormal
risk factors.
The management of most of the traditional risk factors has been dealt
with in more detail in separate sections.
In metabolic syndrome patients who are at high or moderately high risk
for ASCVD events, aspirin prophylaxis is an attractive therapeutic option
to lower vascular events.
Dosage recommendations range from 75 mg to 325 mg per day. The principal
risks of aspirin therapy include gastric mucosal injury and gastrointestinal
hemorrhage. Minor bleeding episodes may occur at low dosages. Contraindications
to aspirin include allergy, tendency for bleeding, anticoagulant therapy,
recent gastrointestinal bleeding and clinically active hepatic disease.
Ticlopidine and recently clopidogrel have also been used either by themselves
or with aspirin. But most studies still maintain the primacy of aspirin
usage.
Although several drugs used to treat other metabolic risk factors have
been reported to reduce CRP levels (eg, statins, nicotinic acid, fibrates,
ACE inhibitors, thiazolidinediones), presently, these drugs cannot be
recommended specifically to reduce a proinflammatory state independent
of their indications for other risk factors.
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