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

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.

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.