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Clinical Care
Part III
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.
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.
Primary Management
Lifestyle Modifications
Lifestyle changes deserve increased emphasis in people with the metabolic
syndrome; 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/ one teaspoon) |
| 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 diet and exercise
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.
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.
Thiazides and ß-blockers are the preferred initial drugs for uncomplicated
hypertensives but may increase insulin resistance and worsen atherogenic
dyslipidemia. 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. 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 evidence suggests 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
For a more detailed discussion on the suggested drug therapy approach
to achievement of blood pressure goal, see Appendix 14
All patients must be prescribed lifestyle changes and this should be continued
even if drug therapy is started.
| Most patients will require multi-drug (3-4)
therapy to achieve and maintain their BP at the optimal levels. |
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