Understanding Uncontrolled High Blood Pressure and the Benefits of Measuring Central Blood Pressure (cBP)

If you’ve been diagnosed with high blood pressure and think you have it under control, there’s a good chance are you are wrong. In fact, according to a study at the Baylor College of Medicine, only 27 percent of Americans who have high blood pressure are able to keep it at levels lower than 140/90 mmHg.(1) Based on the latest research, this level is much higher than recommended for optimal health (i.e., less than 120/80 mmHg).

That means the number of Americans who have their blood pressure under control at healthy levels is actually much lower than 27 percent. (1,2)

I’ve spoken with many people who believe that just because they are taking antihypertensive medication, they don’t need to worry about having a cardiovascular event. However, just because you take the medications your doctor has prescribed for you (if you are actually taking them as ordered), there is still a significant chance your blood pressure is not at a healthy level. (1)

Reining in high blood pressure is a challenge and takes more than a one-shot approach because it is multifaceted condition. Drugs are not enough, and for some people not necessary at all. Instead, patients and physicians alike need to consider diet/nutrition, stress management, and other lifestyle modifications, along with medication, to bring this life-threatening condition under control.

Here’s something else you and your doctors should take into consideration when diagnosing and treating hypertension. Blood pressure becomes elevated only after there have been structural and functional changes in your blood vessels. These changes occur before you get a diagnosis of hypertension. However, what if we could predict the possibility of hypertension by evaluating subclinical (not yet apparent) indicators and thus take steps to prevent the onset of high blood pressure and the associated complications that go with it?

Dangers of inadequate blood pressure control

According to the “Heart Disease and Stroke Statistics—2015 Update: A Report from the American Heart Association,” deaths from cardiovascular disease dropped by nearly a third from 2001 to 2011, even though this disease is still the number one killer in the United States. Although the decline in deaths is great news, deaths attributed to high blood pressure rose more than 13 percent during that same time period. Why the contradiction? (3)

Several factors are at play here. One is that uncontrolled hypertension can directly result in what is known as end-organ failure, including kidney failure, heart failure, and other deadly conditions. Although guidelines indicate the need to evaluate patients with hypertension for such organ failure, the assessment methods are insufficient or vague. For now, this insufficiency exists because the methods to assess subclinical vascular damage (i.e., blood vessel and other associated damage that is not yet readily noticeable) are not universally incorporated into clinical practice. A number of other hemodynamic (blood flow dynamic) assessment tools need to be implemented as well, and some of them are discussed below.

Another factor is that many patients with high blood pressure do not take their medications as prescribed. Even if they do, sometimes what’s been prescribed is not adequate. Yet another issue is a hesitancy among some doctors to treat older patients aggressively, which may be the result of fearing a greater risk of side effects in these individuals.

Health professionals need to take a multidimensional approach, encouraging patients to make dietary changes, work to control stress, consider natural supplements, and look at other health conditions that could be contributing to hypertension. All of these factors need to be addressed along with better evaluation and screening methods that go beyond the standard brachial cuff used at your doctors office.

High blood pressure and endothelial dysfunction: A lethal match

One of the key factors to consider in the regulation of blood pressure is the integrity and tone of the blood vessels through which the blood flows. I’m talking about the endothelial cells that make up the vascular smooth muscle that lines the inside walls of your blood vessels. These cells have a critical role in the regulation of blood pressure and blood flow because they release substances that contribute to the relaxation and contraction of vascular smooth muscle. Other factors that impact blood vessel tone include stress, medications, numerous diseases, and diet. (4)

In health individuals, the body naturally provides a balance between the substances that relax and contract the lining of your blood vessels. The introduction of high blood pressure, however, changes that balance. That’s when there’s a risk of developing vascular disease.

At the same time, the endothelial dysfunction can arise if the endothelial cells cannot respond to the demands for greater blood flow by widening or dilating the vessels. Endothelial dysfunction is a primary player in the development of hardening of the arteries, aka atherosclerosis.

Therefore, there are two scenarios that are important here. One, you need to help support and promote endothelial function as a way to reduce the risk of stroke, heart attack, and cardiovascular death associated with hypertension.(5) Two, you should focus on maintaining a healthy blood pressure to ensure the integrity of your endothelial cells.

Standard treatments for high blood pressure

Most people are familiar with the standard treatments for hypertension, which include lifestyle changes (avoiding dietary salt, losing excess pounds, not smoking, getting regular moderate exercise) along with the use of prescription medications. Drugs in the following classifications are typically prescribed: diuretics, beta-blockers, angiotensin-converting enzyme inhibitors, angiotensin II receptor antagonists, and calcium channel blockers. Physicians may also order alpha-blockers, alpha-beta blockers, aldosterone antagonists, central-acting agents, and vasodilators. It’s the norm more than the exception that doctors prescribe two or more antihypertensive medications – mainly because they don’t have adequate information about what will work best for the patient as an individual.

However, even when multiple drugs and lifestyle changes are adopted, many adults still cannot adequately control their hypertension. Part of this inability to manage high blood pressure may lie with patients not completely following all of their doctor’s recommendations. Admittedly it can be a challenge. Another reason is an inadequate arsenal of effective medications to meet the needs of a diverse population of patients with hypertension.

Natural supplements for managing hypertension

One other way to help manage high blood pressure is to consider the use of natural supplements. Here are some of the options and what the scientific research says about each of them.

Grape seed extract

Grapeseed extract is obtained from the pulverized seeds of red wine grapes. Numerous studies have shown that this extract has an ability to improve poor circulation as well as tackle high cholesterol, two factors involved in hypertension. The power of grape seed extract comes from its high content of polyphenols, which are potent antioxidants with an ability to increase the dilation of blood vessels. (6)

One study in particular was a 2016 meta-analysis of the use of grape seed extract in patients with hypertension. A total of 16 clinical trials and 810 subjects were evaluated. Overall the reviewers found that grape seed extract was associate with a significant decline in both systolic and diastolic blood pressures. The impact was more notable among individuals younger than 50 and those who were obese, as well as anyone with metabolic disorders. (7)

Another benefit of grape seed extract is an ability to help improve endothelial function. The results of a laboratory study showed that the extract was able to inhibit the production of a protein associated with endothelial dysfunction and death. (8)

Grape seed extract also can protect against another cardiovascular disease risk: oxidation of low-density lipoprotein (LDL). After eating, elevated levels of lipids (fats, oils, steroids) increase the risk for heart disease in part because they are highly susceptible to oxidation. Research has shown that when individuals consumed grape seed extract along with a meal, the LDL particles were better able to resist oxidative changes. This suggested to investigators that grape seed extract could reduce cardiovascular risk. (9)

The suggested dose of grape seed extract is between 100 and 300 mg/day. This is the amount that has been used in studies and is being prescribed in some countries in Europe. (7)

Coenzyme Q10

The potent antioxidant coenzyme Q10 (CoQ10; aka, ubiquinone) is known for its ability to help cells produce energy. However, researchers have also demonstrated how it can lower both systolic and diastolic blood pressures.

In a meta-analysis involving 12 clinical trials and 362 patients, use of coenzyme Q10 was shown to reduce systolic blood pressure by up to 17 mmHg and diastolic pressure by up to 10 mmHg without any significant side effects. (10) In a more recent (2018) review involving 17 trials and 684 patients, use of coenzyme Q10 significantly lowered systolic but not diastolic pressure. (11)

A typical dose of CoQ10 is 100 to 200 mg daily, but higher doses have been used in research. You should discuss the optimal dose for you with a knowledgeable healthcare provider.

How to manage hypertension and pre-hypertension with lifestyle

What lifestyle treatment strategy should you and your doctor consider if you have prehypertension or hypertension?

• If you have prehypertension (defined as 120-139 mmHg over 80-89 mmHg), your goal should be to bring your numbers down to less than 120/80 mmHg. This can be achieved by adopting certain lifestyle modifications.
• If you have prehypertension as well as diabetes or chronic kidney disease, then your goal should be less than 130/80 mmHg.(12) Both lifestyle modifications and medications are typically recommended.

Lifestyle modifications include the following:

• Increase physical activity to at least 30 minutes of aerobic exercise daily
• Lose weight
• Adopt the “Dietary Approaches to Stop Hypertension” (DASH) eating plan. This way of eating allows a wide variety of foods while also increasing the intake of fiber, calcium, magnesium, and potassium through lots of whole grains, fruits and vegetables and lesser amounts of low-fat dairy, meat, nuts, seeds, legumes, and fats. (13)
• Reduce salt consumption to no more than 2,500 mg daily. If you already have high blood pressure and/or diabetes or kidney disease, then limit yourself to 1,500 mg daily, which is less than 1 teaspoon. Include salt found in all the foods you eat per day.(14)
• Limit alcohol consumption to no more than two drinks daily.

Pomegranate extract and juice

Both pomegranate (Punia granatum L).extract and juice have demonstrated an ability to help support cardiovascular health, and high blood pressure in particular. (15) Pomegranates are especially high in numerous phytonutrients, including punicalagins, the main antioxidant found in the fruit and one that is unique to pomegranates.(16) In fact, this is the phytonutrient emphasized in quality supplements because it is believed to provide the greatest health benefits.

The results of a recent review and meta-analysis showed evidence of these benefits. The research was limited to pomegranate juice, which lowered systolic pressure by a mean of about 5 mmHg and diastolic pressure by 2 mmHg. The authors of the study concluded that “this evidence suggests it may be prudent to include this fruit juice in a heart-healthy diet.” (17)

What about pomegranate extract? In a 2017 article appearing in the Journal of Nutritional Science, 55 subjects were given either a pomegranate extract or placebo daily for eight weeks. At the end of the trial, there was a significant decrease in diastolic blood pressure, but not in systolic pressure. (18)

In another article from the same year, pomegranate extract was administered to rats. The authors noted that the extract enhanced “the endothelium-dependent coronary relaxation” and improved cardiovascular factors, suggesting pomegranate extract has a role in supporting cardiovascular health. (19) .

What is optimal blood pressure?

There are two factors to consider when asking the question, “What is optimal blood pressure?” First, the definition of optimal blood pressure has been changing over the past few decades. In May 2003, the Joint National Committee of the US Department of Health and Human Services issued a report that changed how blood pressure was classified. The Committee added “prehypertension” to the list, which resulted in the following:

• 120/80 mmHg was considered to be optimal for lowering the risk of experiencing cardiovascular events(20)
• 120-139/80-89 mmHg was considered prehypertensive (12)

However, in 2006, researchers determined that blood pressures of 120-129/80-84 mmHg were associated with an 81 percent higher risk of coronary heart disease, ischemic stroke, and other cardiovascular diseases when compared to optimal blood pressure of less than 120/80 mmHg. The experts also noted that blood pressure levels of 130-139/85-89 mmHg were associated with a 133 percent greater risk of cardiovascular events. Prehypertension was noted to be an even higher cardiovascular risk among blacks and people who were obese or who had diabetes.(21)

Then in 2017, the American College of Cardiology and the American Heart Association provided new guidelines, stating that stage 1 hypertension was defined as greater than or equal to 130/80 mmHg. An increase of systolic pressure by 20 mmHg and of diastolic by 10 mmHg doubles a person’s risk of dying from stroke and other cardiovascular diseases. (22)

So clearly it’s important to manage one’s blood pressure with the goal of achieving the optimal pressure of lower than 120/80 mmHg. However, there’s more to the story.

The other factor to consider is, which blood pressure is optimal to measure, brachial or central blood pressure (cBP)?

• Brachial systolic pressure is the measurement of the pressure or force of blood as it pushes against the walls of your blood vessels. It is taken using a traditional arm-cuff device.
• Central systolic blood pressure is the measurement of the pressure in the aorta, the artery that transports blood from the heart throughout the body. Experts believe central blood pressure presents a more accurate idea of whether a person will experience a cardiovascular event or experience organ damage if undiagnosed.
• Central systolic blood pressure can be measured using one of several methods. A noninvasive way to take central systolic blood pressure is to use a tonometer, a small device that is placed on the skin over the brachial artery in the arm to measure the pulse. If you take the pulse and brachial blood pressure measurements together, the central blood pressure can be calculated using a math formula. Another approach involves using a conventional blood pressure cuff that is attached to a specialized device that reads pulse waveforms. Our AtCor Medical subsidiary is the global gold standard in developing devices and software that measures both cBP and arterial stiffness for the worlds leading hospitals, specialist practitioners, and pharmaceutical companies.

It’s important to understand that central systolic blood pressure can be significantly different from brachial systolic readings and that antihypertensive therapy can affect brachial and central systolic blood pressures differently. Research indicates that central blood pressure is more strongly related to end-organ damage than is brachial blood pressure, which suggests central blood pressure is the reading clinicians should be measuring to help them improve management of hypertension.(23-28)

Remember: The central blood pressure represents the true impact that is being imposed on the heart, brain, and kidneys.

Another factor that clinicians should measure when monitoring blood pressure is aortic stiffness. Determining a patient’s aortic stiffness status is helpful in deciding if the patient is at an increased risk of organ damage or other complications even in the presence of only mildly elevated blood pressure.

The bottom line

Blood pressure should not be taken lightly. Given the lack of symptoms associated with high blood pressure, it’s especially critical to keep a close eye on your pressure either by seeing a healthcare provider regularly and preferably having your central (cBP) rather than brachial blood pressure measured. In addition, monitoring blood pressure yourself frequently using an in-home monitoring device is recommended.

Lifestyle modifications and use of supplemental nutrients may help you ward off high blood pressure if you currently have prehypertension. Complementary support also can be of assistance if you cannot adequately normalize your blood pressure using pharmaceuticals alone. Diet, exercise, stress management, and natural supplements, and medications as needed, clearly have a role in helping manage blood pressure.

Ideally, the clinical assessment of blood pressure should involve much more than is currently being done in clinicians’ offices. Measurement of central systolic blood pressure is a start, but if we really want to prevent or reduce hypertension and its complications we need better screening for secondary hypertension, new ways to assess flow dynamics, and evaluation of left ventricular hypertrophy and geometry and arterial pressure waveforms and more efficient ways to refine hypertension management decisions and prevent morbidity and mortality associated with high blood pressure.

References

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