Hypertension and Comorbidities | A dangerous combination

Over 70% of hypertensive adults are living with at least one other comorbid condition. But despite this increased risk of developing one or more comorbidities from hypertension, not even half of this population actually has their blood pressure under control [2]. In this post, we’ll review what comorbidities are, explain common (and some less common) comorbidities of hypertension, share tips for managing hypertension with comorbidities, and discuss how innovations in in-home health monitoring could help doctors and patients improve health outcomes.

What are Comorbidities?

Comorbidities are two or more diseases that are present in a person at the same time.

While there are many risk factors for comorbidities, age and blood pressure are two big ones. Although hypertension (or chronic high blood pressure) can occur by itself, it greatly raises your chances of developing other types of health issues like brain, heart, or kidney diseases. This means that a person with hypertension is highly likely to have, or eventually develop, at least one other disease. In fact, for hypertensive adults over 60 to 65 years old, their probability of developing at least one comorbid condition reaches at least 50% [8].

Dealing with multiple diseases can make treating and managing your health very complex. Having a basic understanding of how each disease impacts your body may help you to recognize why it is so important to self-manage. In this post, we will explain the physiology of some common and uncommon comorbidities associated with hypertension.

Common Comorbidities

There are many comorbidities that have been seen in hypertensive patients. Some of the most common comorbidities associated with hypertension include [1]:

  • Coronary artery disease (CAD)

  • Stroke

  • Heart failure (HF)

  • Chronic kidney disease (CKD)

  • Chronic obstructive pulmonary disease (COPD)


In this section, we’ll explain the basics of each condition, as well as how each one contributes to hypertension, and vice versa.

Coronary Artery Disease

Coronary artery disease (CAD) occurs when plaque—a combination of cholesterol, fatty deposits, and other substances from your diet—builds up in the arteries that supply blood to your heart. This buildup causes the vessels to narrow over time and can eventually lead to a blockage. Blood has more trouble flowing through the blood vessels when this happens and the oxygen supply to the heart’s muscle tissues can eventually become completely cut off. This event is called a myocardial infarction, more commonly known as a heart attack.

When someone has hypertension, their artery walls are under more stress from the high blood pressure. If left untreated, this extra force can cause damage to the arteries making them more susceptible to plaque buildup and therefore at a higher risk for developing CAD [12].

In patients with CAD, their obstructed arteries can lead to a buildup of blood. As the fluid accumulates, so does pressure. If this becomes a chronic issue, the patient can develop hypertension. Notably, studies have shown that decreasing systolic blood pressure by 10 mmHg and diastolic blood pressure by 5 mmHg in adults with CAD reduces the likelihood of having a cardiovascular event caused by the condition by 24% [12].

Stroke

A stroke occurs when your brain is deprived of oxygen from a lack of adequate blood supply. There are two kinds, hemorrhagic and ischemic. A hemorrhagic stroke happens when a blood vessel near your brain ruptures and is unable to deliver the blood where it needs to go. This only accounts for about 13% of strokes. An ischemic stroke occurs when the blood flow to the brain is cut off from the vessel being too narrow or clogged. Ischemic strokes make up about 87% of strokes [1].

In a study conducted by Noh et al., subjects with hypertension were found to be over three times more likely to experience a stroke than those without [10]. The occurrence of ischemic stroke and for hemorrhagic stroke can be largely prevented by controlling your blood pressure. Because of the added physical stress on their inner walls, hypertension is more likely to lead to ruptured or narrowed blood vessels. Therefore, maintaining a normal blood pressure is crucial for lowering your risk of developing a stroke.

Chronic Kidney Disease

Your kidneys have a very important role in maintaining your health. When blood circulates throughout the human body, it collects excess fluid and waste products from the cells. Once the blood reaches the kidneys, the fluid and chemicals are then filtered out and expelled from the body in urine [3].

Chronic kidney disease (CKD) is a condition defined as having a “gradual loss of kidney function” [3]. Being unable to properly filter your blood poses a major threat to your health and can lead to a variety of possible complications, including hypertension. Without fully functioning kidneys, the excess fluid that is normally disposed of will accumulate. As this happens, your blood volume increases. The more liquid traveling through your blood vessels, the more pressure there is being exerted on them, which will eventually lead to high blood pressure (or higher blood pressure). Your kidneys also produce hormones that regulate blood pressure and are not released if the organs are damaged [9].

Hypertension impacts your kidneys in multiple ways that can result in CKD. Not only can high blood pressure harm the blood vessels that feed the kidneys and other organs, but it can also damage the kidneys’ nephrons, or little filters. In both of these cases, the kidneys’ filtration systems become compromised and they are then unable to get rid of the waste products, as well as the excess fluids from the blood [9].

Heart Failure

Heart failure is a chronic condition in which your heart is unable to pump enough blood out of the ventricles and into the arteries, as well as to your other organs. Hypertension is a frequent cause of heart failure. When you have high blood pressure, your heart has to work harder to pump the blood against that pressure into your arteries. Over time, the added stress on the heart muscle will cause concentric hypertrophy to occur. Concentric hypertrophy occurs when the walls of the heart chamber thickens, while the size of the chamber itself stays the same. While one may think this would make the heart stronger, having thicker walls actually makes the muscle more stiff and prevents it from being able to contract as easily. If the hypertension is left untreated, concentric hypertrophy can eventually give rise to eccentric hypertrophy, or a growth in the size of the heart’s chamber rather than its walls. Dilation of the ventricle damages the muscle tissue, weakens the ventricular walls and ultimately makes your heart muscle unable to effectively pump out blood to circulate through your body [6].

On the other hand, heart failure can also cause hypertension. When the heart is unable to pump as much blood out of its left ventricle, it can cause a chronic backup of fluid throughout the pulmonary circuit or the blood vessels that transport blood between the heart and lungs. If left untreated, this will typically lead to pulmonary hypertension, or high blood pressure within this circuit.

Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease or COPD is a chronic inflammatory lung disease that causes blocked airflow from the lungs [4]. Every person has a trachea, your windpipe, that splits into two large tubes known as bronchi. One bronchus feeds your left lung with air while the other brings air into your right lung. In patients with COPD, their bronchi are constantly inflamed and coated in a thick layer of mucus. This causes their airways to narrow and restricts the amount of air that can be inhaled.

In addition to the bronchi, small arteries carrying blood from the heart to the lungs become more narrow from the inflammation. This means blood will travel much slower through the lungs and it leads to a buildup of pressure in those vessels. High blood pressure in these arteries is referred to as pulmonary hypertension.

“Hypertension is the most frequent comorbidity in patients with COPD” [1]. This makes sense because our respiratory and cardiovascular systems function interdependently.

Uncommon Comorbidities

It is important to point out that the less common comorbid conditions are frequently underestimated and treatment often consists of only self-prescribed medications [1]. Rheumatic diseases and psychiatric diseases are two good examples of uncommon comorbidities associated with hypertension that we shouldn’t ignore.

Rheumatic Diseases

Rheumatic diseases affect joints or tendons causing pain and inflammation. They are typically autoimmune diseases, which means that the body is being attacked by its own immune system. An example is rheumatoid arthritis (RA) where the body’s immune system attacks joints and results in pain, stiffness, and swelling.

“[O]ver 50% of premature deaths in RA are attributed to CVD” from hypertension [11]. Cardiovascular disease (CVD) is an umbrella term for conditions involving the heart or blood vessels such as coronary artery disease, heart attack, and heart failure. Unfortunately, researchers still don’t know exactly how autoimmune diseases can cause hypertension. They think it may have to do with the relationship between the immune system and the kidneys. Because of this relationship, the inflammation from a dysfunctioning immune system can damage the kidneys, which can lead to hypertension (as discussed earlier in this post) [11].

Psychiatric Diseases

Although researchers haven’t yet found solid evidence to prove that psychological stress alone causes hypertension, psychiatric disorders like depression have been linked to the condition. If you have ever taken your blood pressure while you were feeling nervous or upset, you may have noticed that the readings were higher than usual. This is because there is a strong connection between blood pressure and psychology. When you are under stress, your body releases a wave of hormones. Some of these hormones act on your cardiovascular system and raise your blood pressure by increasing your heart rate, as well as constricting your blood vessels [7]. This is also known as our “fight or flight” response. Since even acute anxiety or sadness can raise blood pressure, it makes sense that patients dealing with chronic anxiety or depression from a psychiatric disorder may be more likely to also develop chronic high blood pressure [1].

How to Manage Your Hypertension & Comorbidities Better on Your Own

Having hypertension and comorbidities not only greatly increases your cardiovascular risk, as well as the potential for adverse health outcomes, but it also makes managing your health much more challenging. In a recent study, Fix et al. identified four major reasons why most people often have trouble managing their hypertension on their own. Here are some tips that may help you solve this issue.

1 -- Stop viewing your hypertension and comorbidity as one illness

Researchers have found that for those who have multiple conditions to treat, they tend to look at their health as a single experience. In other words, they treat their conditions as a whole without paying much attention to the repercussions of each independent from the other. Doing so causes individuals to have more trouble separating their illnesses and thus keeping a close enough eye on each condition.

2 -- Don’t leave your hypertension on the back burner

You may have heard hypertension be referred to as the Silent Killer because it is very common for high blood pressure to be asymptomatic. As a result, the condition is repeatedly given lower priority than more “visible” comorbidities and it is overlooked.

3 -- Look for ways around conflicts between the conditions’ treatment plans

If the treatment plan for hypertension conflicts with the comorbidity’s treatment plan, the one for hypertension is generally neglected. For example, maintaining a low-sodium, low-sugar diet suitable for hypertension and diabetes is difficult to do because there aren’t very many foods that satisfy both of these requirements [2]. Although finding solutions under circumstances like these can be challenging, it is extremely important that you not allow one treatment plan to limit the other as much as possible. It may be worth it to speak with your doctor if you are having trouble dealing with conflicts between your treatment plans.

4 -- Keep track of all of your medications

In addition to making positive changes to your daily behavior, hypertension usually needs to be treated with medication. However, if you are hypertensive with one or more comorbidities, you may need to take even more medications on a regular basis to maintain each condition. Keeping track of the time of day, dose, name, purpose, and how often you need to take each one can be very difficult and this is a major reason why patients struggle with keeping their hypertension under control [2]. Fortunately, groups like the American Heart Association and the U.S. Department of Health & Human Services offer some free resources like this Medications Log and this Daily Medicine Schedule to help you manage your medications and overall health.

And while some people may think the task of managing multiple conditions isn’t much different from only managing one, rarely is that actually the case.

Effortless At-Home Health Monitoring

Comorbidities make it more challenging for hypertensive patients to keep their blood pressure and overall health under control because there is more that they need to pay attention to. Managing multiple health conditions can feel overwhelming and may make you more likely to abandon your regimens. That is why finding ways to handle your chronic conditions seamlessly, without having to change your daily behavior, is so valuable.

It is recommended that everyone take their blood pressure twice a day (morning and evening), each time gathering two to three readings [5]. Doing this will give you a better sense of your health status, which is especially important for those dealing with hypertension. This routine is pretty simple, but adhering to it (and the rest of your treatment plans) isn’t easy. Being able to eliminate or streamline some of these additional tasks using new services or technology is something that more and more companies are trying to solve. Imagine being able to monitor and send your doctor updates about your blood pressure every time you use your bathroom with technology that is so easy-to-use, you forget it’s even there.

The Heart Seat does just this. Its innovative design makes this seemingly normal toilet seat truly extraordinary. The seat is equipped with sensors that use direct contact with bare skin to monitor your health. Those health readings are made available to your care team, and your doctor is alerted whenever readings fall outside your normal thresholds. Casana’s goal in developing the Heart Seat is to make managing your health easier and more effective. For people managing hypertension and its comorbidities, an effortless solution for regularly monitoring blood pressure could provide the information and context needed for better treatment and a return to better health.

Citations:

[1] American Heart Association. (June, 2020). 2020 International Society of Hypertension Global Hypertension Practice Guidelines; https://www.ahajournals.org/doi/epub/10.1161/ HYPERTENSIONAHA.120.15026

[2] Fix, G.M., Cohn, E.S., Solomon, J.L., Cortés, D.E., Mueller, N., Kressin, N.R., Borzecki, A., Katz, L.A., & Bokhour, B.G. (2014, June 10). The role of comorbidities in patients’ hypertension self-management. Chronic illness. https://journals.sagepub.com/doi/10.1177/174239 5313496591

[3] Mayo Clinic. (2019, August 15). Chronic Kidney Disease. https://www.mayoclinic.org/ diseases-conditions/chronic-kidney-disease/symptoms-causes/syc-20354521

[4] Mayo Clinic. (2020, April 15). COPD. https://www.mayoclinic.org/diseases-conditions/copd/ symptoms-causes/syc-20353679

[5] Mayo Clinic. (2020, September 18). Get the most out of home blood pressure monitoring. https://www.mayoclinic.org/diseases-conditions/high-blood-pressure/in-depth/high-blood-pressure/art-20047889

[6] Mayo Clinic. (2020, May 29). Heart Failure. https://www.mayoclinic.org/diseases-conditions/ heart-failure/symptoms-causes/syc-20373142

[7] Mayo Clinic. (2021, March 18). Stress and high blood pressure: What’s the connection? https://www.mayoclinic.org/diseases-conditions/high-blood-pressure/in-depth/stress-and-high-blood-pressure/art-20044190

[8] Moser, M., Miller, N.H., Jaffe, M., & Gifford, R. (2000, April). Roundtable Discussion: Hypertension and Comorbidities. The Journal of Clinical Hypertension. https://onlinelibrary.wiley. com/doi/epdf/10.1111/j.1524-6175.2001.00460.x

[9] National Kidney Foundation. (2010). High Blood Pressure and Chronic Kidney Disease. https://www.kidney.org/sites/default/files/docs/hbpandckd.pdf

[10] Noh, J., Kim, H.C., Shin, A., Yeom, H., Jang, S., Lee, J.H., Kim, C. & Suh, I. (2016, September 28). Prevalence of Comorbidity among People with Hypertension: The Korea National Health and Nutrition Examination Survey 2007-2013. https://www.ncbi.nlm.nih.gov/ pmc/articles/PMC5054180/

[11] Taylor, E.B., Wolf, V.L., Dent, E. & Ryan, M.J. (2018, June 13). Mechanisms of hypertension in autoimmune rheumatic diseases. British Pharmacological Society. https://bpspubs.online library.wiley.com/doi/epdf/10.1111/bph.14604

[12] Weber, T., Lange, I., Zweiker, R., Horn, S., Wenzel, R.R., Watschinger, B., Slany, J., Eber, B., Roithinger, F.X. & Metzler, B. (2016, March 15). Hypertension and coronary artery disease: epidemiology, physiology, effects of treatment, and recommendations. https://link.springer.com/ article/10.1007/s00508-016-0998-5#citeas

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