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Download Metabolic
Syndrome
HYPERTENSION
Hypertension is a risk parameter in the
diagnosis of the metabolic syndrome. A raised systolic blood pressure
>/= 135 mm Hg and/or a raised diastolic blood pressure >/=85 mm
Hg are the criteria leading to the diagnosis of hypertension.
At the same time, it is now accepted that the relationship between
BP and risk of cardiovascular disease (ASCVD) events is continuous, consistent,
and independent of other risk factors, although the presence of the other
risks does significantly increase the ASCVD risk posed by the high blood
pressure levels. The classification prehypertension, introduced in the
JNC-7 report, recognizes this relationship and introduced a new category
of "prehypertension" (120 to 139/80 to 89 mm Hg), in recognition
of the fact that underlying risk factors raise blood pressure to ranges
that increase risk for CVD.
Stages of Hypertension as Recommended by JNC 7
| Blood pressure stages |
| Prehypertension (120 to 139/80 to 89 mm Hg) |
| Stage 1 (140 to 159/90 to 99 mm Hg) |
| Stage 2 (>=160/>=100 mm Hg) |
JNC = Joint National Committee on Prevention, Detection, Evaluation,
and Treatment of High Blood Pressure.
For individuals aged 40 to 70 years, each increment of 20 mm Hg in systolic
BP or 10 mm Hg in diastolic BP doubles the risk of CVD across the entire
BP range from 115/75 to 185/115 mm Hg.
Benefits of Lowering BP
In clinical trials, antihypertensive therapy has been associated with
35% to 40% mean reductions in stroke incidence; 20% to 25% in myocardial
infarction; and more than 50% in HF. It is estimated that in patients
with stage 1 hypertension (systolic BP, 140-159 mm Hg and/or diastolic
BP, 90-99 mm Hg) and additional cardiovascular risk factors, achieving
a sustained 12-mm Hg decrease in systolic BP for 10 years will prevent
1 death for every 11 patients treated. In the presence of CVD or target-organ
damage, only 9 patients would require this BP reduction to prevent a death.
Hypertension is more commonly prevalent in patients with diabetes as compared
to people without diabetes. It may or may not be accompanied by renal
damage, but is a major risk factor for the development of macro/micro
vascular disease in diabetics.
When overt hypertension is present without diabetes or chronic kidney
disease, the goal for antihypertensive therapy is a blood pressure of
</=130 systolic and </= 85 mm Hg. In the presence of diabetes or
chronic kidney disease, the blood pressure goal is <120/80 mm Hg.
Treatment Strategies for High Blood Pressure
Primary Management
Lifestyle Modifications
Lifestyle changes deserve increased emphasis in people with the metabolic
syndrome; the goals here are to reduce blood pressure as much as possible
even in the absence of overt hypertension and to obtain other metabolic
benefits of lifestyle change. Mild elevations of blood pressure often
can be effectively controlled with lifestyle therapies: weight control,
increased physical activity, alcohol moderation, sodium reduction, and
increased consumption of fresh fruits and vegetables and low-fat dairy
products.
| STOP smoking |
| Lose weight if overweight, even a loss of 4 to 5 kg lowers blood
pressure in many hypertensives |
| Increase aerobic physical activity (30 to 45 min most days of the
week) |
| Reduce sodium intake to no more than 100 meq/day (2.4 g of sodium
or 6 g of sodium chloride) |
| Consumption of an overall healthy diet such as a carbohydrate-rich
diet that emphasizes fruits, vegetables, and low-fat dairy products;
includes whole grains, poultry, fish, and nuts; and is reduced in
fats, red meat, sweets, and sugar-containing beverages. Replacement
of some carbohydrates with either protein from plant sources or with
monounsaturated fat can further lower BP. |
| Reduce intake of dietary saturated fat and cholesterol |
| Maintain adequate intake of dietary potassium (approximately 90
meq/day) Increase intake of fruit and vegetables (which provides a
substantial intake of potassium) unless there are contraindications. |
| Maintain adequate intake of dietary calcium and magnesium for general
health |
| Limit alcohol intake to no more than 1 oz (30 ml) of ethanol (eg,
24 oz [720 ml] of beer, 10 oz [300 ml] of wine, or 2 oz [60 ml] of
100-proof whiskey) per day or 0.5 oz (15 ml) of ethanol per day for
women and lighter-weight people |
Many of these aspects have been discussed in detail in the section dealing
with lifestyle changes.
If hypertension cannot be adequately controlled by lifestyle therapies,
antihypertensive drugs usually are necessary to prevent long-term adverse
effects.
The selection of an appropriate drug regimen for the management of hypertension
in diabetics entails special consideration as many of the drugs used for
hypertension may have adverse consequences on other risk factors, especially
diabetes.
No particular antihypertensive agent has been recommended as a first line
drug to be used in patients with hypertension having the metabolic syndrome.
No particular antihypertensive agents have been identified as being preferable
for hypertensive patients who also have the metabolic syndrome.
Some investigators support angiotensin-converting enzyme (ACE) inhibitors
as first-line therapy for hypertension in the metabolic syndrome, especially
when either type 2 diabetes mellitus or chronic renal disease is present.
Indeed, inhibition of the renin-angiotensin system with ACE inhibitors
or angiotensin receptor blockers (ARBs) may lower risk for diabetes itself.
ARBs may be used in those who cannot tolerate ACE inhibitors or as an
alternative to ACE inhibitors in people who have left ventricular dysfunction.
Available clinical trial data suggest that thiazides and ß-blockers
are the preferred initial drugs for uncomplicated hypertensives but may
increase insulin resistance and worsen atherogenic dyslipidemia. The results
of a large clinical trial raised the possibility that use of diuretics
in patients with IFG or IGT may increase the likelihood of progression
to type 2 diabetes mellitus, although diuretics do in fact lower the risk
for cardiovascular events. For thiazide diuretics, doses should be kept
relatively low in accord with current recommendations. Most investigators
in the hypertension field believe that the potential benefit of low-dose
diuretics in combination antihypertensive therapy outweighs their risk.
ß-Blockers, especially the newer and more selective drugs are cardioprotective
in patients with established CHD and are no longer contraindicated in
patients with type 2 diabetes.
At this time, however, the majority of clinical trials indicate that most
of the risk reduction associated with antihypertensive drugs is the result
of blood pressure lowering alone.
One suggested approach to a patient with elevated blood pressure
All patients must be prescribed lifestyle changes and this should be continued
even if drug therapy is started.
Some points about the suggested drug therapy approach to achievement of
blood pressure goal:
All patients must be prescribed lifestyle changes and this should be continued
even if drug therapy is started.
If BP <15/10 mm Hg above goal (130/80 mm Hg), then ACE inhibitors (ACEi's)
or Angiotensin Receptor Blockers (ARBs) alone may be used to initiate
therapy. The doses can be gradually increased, as needed to the highest
dose range to achieve the blood pressure goal;
If this does not allow for optimal control, add a small dose of a thiazide
diuretic.
If the patient has a blood pressure of >15/10 mm Hg above the goal
(<130/80 mm Hg), begin therapy with a combination of an ACEi or ARB
and a thiazide diuretic, increasing the dosage of the former, as needed,
to the high-dose range to achieve the blood pressure goal.
In both the above cases, if blood pressure is still not controlled, add
a calcium channel blocker (CCB); a nondihydropyridine CCB is recommended
for those with proteinuria of >300 mg/day. Non-dihydropyridine CCBs,
verapamil, diltiazem have been shown to reduce both CV mortality, proteinuria
and diabetic nephropathy progression independent of an ACE inhibitor.
Beta blockers may be substituted for calcium channel blockers if the patient
has angina, heart failure, or arrhythmia necessitating their use. The
newer highly selective beta blockers with proven efficacy to reduce CV
events and the lowest side effect profile are preferred.
The use of a beta blocker with a nondihydropyridine CCB should be avoided
in the elderly and those with conduction abnormalities. Otherwise, such
combinations are safe and particularly effective for lowering blood pressure.
If the blood pressure is still not at the optimal level, add a long acting
alpha blocker at bedtime
Most patients will require multi-drug therapy
to achieve and maintain their BP at the optimal levels.
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