High Blood Pressure

Hypertension

  • common
  • costly
  • many medications available, but still many people have hypertension “resistant to medication” despite the concurrent use of 3 different meds together
  • for people who have hypertension, using medication to lower blood pressure  to the treatment target range is very worthwhile, compared to continuing high blood pressures. Unfortunately, even having blood pressure successfully treated to target does not fully make up for the harmful effects of having hypertension. The person is still more at risk than a comparison group of people who do not have hypertension (see below). Thus, having hypertension and a treated blood pressure in the normal range is still a higher risk situation than simply innately having blood pressure in the normal range. This ups the ante on the value of prevention of hypertension. (Not forgetting that having a treated blood pressure in the target range is still better than having continuing high blood pressure.)

From the study report (see link below):

“This study demonstrates that there is an increased residual risk of stroke in hypertensive persons whose SBP is normalized with pharmacological therapy compared with untreated normotensive persons. Forty-six percent of the participants in the study were well-controlled hypertensive individuals, and an approach that waits to treat hypertension after it becomes prevalent places these individuals at a risk of stroke between 1.42× and 2.48× greater than normotensive individuals not on treatment. Therefore, there is a substantial lost opportunity from not focusing prevention efforts on primordial prevention of hypertension—that is, interventions to prevent individuals from developing prehypertension and hypertension. There are well-documented interventions to prevent or delay the development of hypertension, although success in implementing these in the general population is challenging.”

Resiliency

There are many aspects of diet, lifestyle and personal choice matters that can help prevent the development of hypertension and/or lessen the need for medication in treatment. For example:

  • regular physical activity
  • relaxation and stress management
  • avoiding weight gain
  • for people who have higher body weight and/or extra adipose tissue inside the abdomen, reducing extra body fat according to what is individually worthwhile and attainable
  • for the many people who have uncompensated insulin resistance, the blood pressure will either return to normal or be more responsive to less medication if they “unplug” the demand for high insulin levels by eating a “low insulin demand” diet. This is helpful in many ways, including by lessening sodium (salt) retention
  • salt restriction is often recommended. For those with certain medical problems, such as heart failure or hypertension, this is a topic for discussion with your doctors. For those who are generally well, a low salt intake is often recommended to prevent the development of hypertension. This has become a highly disputed topic among the world’s top experts in the field – see more on the “salt” page.

A person’s blood pressure naturally goes up and down often in the day, in response to different events and states that trigger various responses in your body.

So, you can have blood pressure that is high for moments or for periods of time – such as during strenuous activity or when frightened. When you think about it, it’s a good idea for your body to prepare you to run for your life if you are suddenly frightened.

We use the medical term “hypertension” when a person’s blood pressure is up generally through the day and over a period of time (not just one bad day or two).

So, you can have blood pressure that is “high” without having the medical condition “hypertension”. For example, this happens commonly in doctor’s offices because often people are worried during their visit and the stress shows as high blood pressure. In that situation, if the person is left to rest and relax for a while, checking the blood pressure again will generally show that the pressure has quickly returned to normal.

If you have hypertension and are taking a medication that is successful in “controlling” it, when you take your blood pressure reading it will not be high. So, a person can have “hypertension” while having a normal blood pressure reading. What makes it the medical condition “hypertension” is that without the medication, the blood pressure would be high. In hypertension, there is some internal state of your body that would result in your blood pressure being high – this can be “controlled” or “uncontrolled” depending on whether you are under an effective medical treatment or not.

There are many causes for hypertension. Just for one example, there can be a partial blockage of the blood flow into one of your kidneys. The kidney responds to the drop in blood supply by releasing hormones that drive the blood pressure up. There are multiple uncommon or rare causes, and a few common causes.

The commonest “cause” of hypertension is essential hypertension, also known as “idiopathic” hypertension. The term means that the cause is not known.  There are likely many different factors that act separately or in various combinations to cause essential hypertension. For example, poor nutrient supply in utero is though to be a contributing factor – especially if it was bad enough to cause growth restriction.

There has been extensive study of the issue of “salt sensitivity” in hypertension. Some people are “sensitive” to high intakes of salt. This term means that their blood pressure goes up when their intake of salt is high and goes down when the intake of salt is low. There is no one cause for this and research continues.

There is some evidence that having a high intake of potassium can blunt the effects of salt sensitivity. This is the basis for the widely known DASH diet for hypertension – which incorporates a low sodium intake plus a high potassium intake. Of note – many people in the general population have fairly low intakes of potassium in their habitual eating pattern.

One of the causes of salt sensitivity (but not the only one) is high blood insulin levels, as seen in uncompensated insulin resistance. With insulin resistance, the blood levels of insulin go up to counter-balance the resistance to insulin effects. Over time, this condition tends to get worse and worse. The blood levels of insulin can get very high. Over many years of this, the pancreas starts to fail to meet this very high demand for it to make and secrete insulin. When the pancreas cannot meet the demand for insulin production, the blood glucose levels cannot be controlled, as the blood glucose levels start to go up. This tends to get worse over time. The insulin levels put out by the failing pancreas then are not as very high as previously, but the blood glucose has become too high. This is what is going on in pre-diabetes and, when the situation gets worse, in type 2 diabetes.

Insulin has many effects on metabolism. When insulin blood levels are high, especially when this is sustained over time, there are a number of ways your body can develop harmful effects. High insulin levels promote the retention of sodium in the body. The high sodium levels then cause the body to retain water. This promotes higher blood pressure. This high insulin/ higher glucose state also promotes inflammation, which itself is thought to contribute to the development of hypertension. Insulin resistance also promotes a tendency to gain fat inside the belly – intra-abdominal fat – which also promotes inflammation.

This cycle can be “unplugged” by finding ways to reduce the demand for insulin, so the blood levels of insulin drop. For some people, simply switching away from a high intake of sugars or fast-digested processed starches will bring major changes in health by directly lessening the demand for insulin. Any thing that will lessen the degree of insulin resistance will also indirectly drop the demand for such high insulin levels – such as exercise, weight loss, adequate sleep, etc.

Your body needs a certain small amount of insulin in the blood stream all the time to keep the metabolism running smoothly and to keep blood sugar levels normal over the day and night – whether you are eating or not. However, this demand for insulin is small. The amount of insulin needed to cope with your meals can be fairly small or a lot – depending on how much you eat, of which foods, in what time period and over what time period they are digested and absorbed.

You can “pull the plug” on this cycle of high insulin damage by making food choices that require less insulin to handle. Any change in the direction of reducing demand for insulin will help – but maybe not help enough to have a notable effect on one’s health. Depending on any one person’s degree of insulin resistance, smaller changes or bigger changes will be needed to make this strategy bring evident benefits.

With diet changes that substantially reduce the need for insulin response to meals, the resulting lower insulin levels then reduce the drive for sodium retention, reducing how much water is being held in the body. For example, when people switch to a low carb diet, it is routine to notice a higher amount of urine coming out for some days, and often a quick drop in blood pressure.

In fact, this leads to one of the major cautions about dietary changes, especially about starting a low carb diet. If you are on any medications that lower blood pressure, it is critically important to discuss this situation with your doctor before making dietary changes. The use of medications and the blood pressure must be carefully monitored and considered on a day-by-day basis over the first days and weeks. It is often best to consider some reduction of any such medications just at the start of the diet changes or within the first days and weeks. If a person is taking any medications that can have the effect of reducing blood pressure, it is certainly possible for the blood pressure to drop so quickly that these previously-needed medications become harmful instead of helpful, driving the blood pressure down too far. Serious medical consequences, including falls and injury can result.

Note: this caution re: changes in diet applies to all medications that have the potential to lower blood pressure – whether the person is specifically on them to lower blood pressure or whether they are on any medication for any reason at all  which has the possible effect of lowering blood pressure. For example, a person with no history of hypertension may be on a medication for their heart  – but that medication may also be one that is known to lower blood pressure. Someone may be on a diuretic to help control swelling in the ankle, without realizing that all diuretics have a blood-pressure lowering effect.

Note: there are other cautions that apply regarding various diet changes, the above is just a small part of the story. Please carefully study other information sources and then discuss your personal situation with your doctor.

Related:

“Hypertension cost Alberta health-care system $1.4B in 2010, says study”

by Erika Stark, Calgary Herald, August 12, 2015  LINK

“About 10 per cent of Alberta’s annual health budget goes toward treating high blood pressure and its related complications, a new study from the University of Calgary shows.”

“Is Blood Pressure Control for Stroke Prevention the Correct Goal?  The Lost Opportunity of Preventing Hypertension”

LINK  to full text, Stroke 2015 May 07; G Howard, M Banach, M Cushman, DC Goff, VJ Howard, DT Lackland, J McVay, JF Meschia, P Muntner, S Oparil, M Rightmyer, HA Taylor

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