Under pressure

Both my parents used to have the same conversation on the phone with their patients: “Your blood pressure is a little high. We can medicate for that, but it’s better if you can get it down on your own before we go to pills.” This was a consistent speech, along with the hypercholesterolemia speech that I had the opportunity to memorize throughout my childhood. That was my first experience with the idea of population health and it has always hummed in the background.

Many physicians know those two conditions as part of the chronic three: hypertension, hypercholesterolemia (or hyperlipidemia, but hypercholesterolemia refers specifically to high cholesterol while hyperlipidemia refers to any kind of fat in the blood stream) and diabetes. These three are linked to a host of other health conditions, ranging from cardiovascular disease to stroke to some cancers. These three are incredibly widespread in the U.S., particularly in older adults, who are at higher risk. Nearly a third of the U.S. adult population was diagnosed with hypertension as of 2012, according to the CDC; diabetes mellitus hovers around 9.3 percent, as of 2014; and hypercholesterolemia is slightly less than hypertension, coming in at approximately 31.7 percent.

Diagram of cholesterol buildup in the artery and how it can contribute to high systolic blood pressure. Original illustration from the CDC.
Diagram of cholesterol buildup in the artery and how it can contribute to high systolic blood pressure. Original illustration from the CDC.

These are all chronic conditions that are manageable. However, this is the first time in history they have been so widespread, and the host of conditions associated with them are far more serious. A recent study published in the journal The Lancet evaluated the conditions associated with the highest risk of death worldwide. The most common offender? High systolic blood pressure.

The study, which evaluated the death-risk factors for 2013, found that high systolic blood pressure contributed to 10.4 million deaths worldwide that year. This is 49.1 percent more deaths aided by high systolic blood pressure than in 1990. The rise was more dramatic for men than for women, according to the study.

Fourth on the list for death risk worldwide was high fasting plasma glucose, associated with diabetes mellitus. Ninth was high total cholesterol.

What’s galling is that these risk factors are avoidable. Physicians have been puzzling over how to advise patients best on how to lose weight and to lower their blood pressure, but its a kaleidoscope of risk factors. The National Institutes of Health rang alarm bells by cutting short a study it says already “definitively shows” that the current recommendations for systolic blood pressure are too high.

The study, which began in 2009, studied approximately 9,300 people age 50 and over from a variety of racial and ethnic group around the U.S. and Puerto Rico. The control group was given medication and told to keep their systolic blood pressure reading lower than 140 mmHg, the current top recommendation for that age group. The experimental group was told to aim for lower than 120 mmHg, considered the middle of the normal range.

The NIH announced last week that it was already clear that the experimental group was experiencing better health outcome and that announcing the results now could help save lives.

“Our results provide important evidence that treating blood pressure to a lower goal in older or high-risk patients can be beneficial and yield better health results overall,” said Lawrence Fine, M.D., chief, Clinical Applications and Prevention Branch at and National Heart, Lung and Blood Institute in the press release. “But patients should talk to their doctor to determine whether this lower goal is best for their individual care.”

These are, of course, early findings that must be reconciled with future studies. But it follows a trend in health studies: our target goals for these health markers have been consistently too high. About 12 years ago, the Adult Treatment Panel lowered its recommended guideline for LDL (commonly known as “bad cholesterol”) and updated it to an even lower recommendation about 10 years ago. But in 2013, it abandoned the guideline entirely, saying that there was no evidence that adhering to a specific guideline helped prevent disease. Instead, physicians were recommended to watch for all risks of heart disease.

Changes in hypertension prevalence in the U.S. over time, up through 2010. Original image from the CDC.
Changes in hypertension prevalence in the U.S. over time, up through 2010. Original image from the CDC.

So what does it exactly mean when your blood pressure is high? What does it mean for your health if your blood pressure is elevated?

Blood pressure is the amount of pressure (mmHg) applied to the walls of your arteries by your blood pumping through them. The reason there are two readings is because the pressure varies between when your heart is pumping and it is not: systolic is for when your heart pumps, and diastolic is for when it is not. Hence why the diastolic number is always smaller.

The frustrating thing is that we don’t really know why blood pressure elevates. We know that when the reading is higher, your heart is working harder to pump your blood through, but we’re still not entirely sure of the reasons why. Common medications for hypertension are ACE Inhibitors, channel blockers and diuretics. ACE inhibitors relax the blood vessels and decrease the blood volume by inhibiting the angiotensin-converting enzyme. Channel blockers inhibit the flow of calcium, decreasing wall stiffness. Diuretics are any type of drug that encourage the flow of urine, decreasing the amount of fluid in the body in general to help decrease pressure.

If we can further study the actual causes of hypertension and its effects on the heart, we can better understand how to control and possibly cure it. There are a lot of lives riding on it, and to control something, we have to first understand it.

Maybe then doctors can stop tearing their hair out over how to get their patients’ numbers below 120 so they can get paid.

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