Hypertension: What’s Taking Your Pressure Higher?

Hypertension
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Hypertension: What’s Taking Your Pressure Higher?

February is American Heart Month. It provides an opportunity to include a public service message on one of the most centralized and cherished organs in our body—the heart.

Approximately 1 in 2 adults living in the United States lives with hypertension, another word for high blood pressure. Not only can it cause significant complications, such as heart disease, stroke, kidney disease, and eye disease, but it can also be lethal. Over this last year during the COVID-19 pandemic, we learned of a new risk of hypertension: severe COVID-19. Individuals with hypertension have a 2.5-fold greater risk for severe COVID-19.  Similarly, other conditions such as diabetes, obesity, and advanced age are also associated with more severe outcomes of COVID-19. As much as these conditions can be treated as separate, unrelated entities in the clinic, they are not. In fact, they all carry with them an increased association with hypertension.

What follows is a summary of hypertension and its associated conditions, obesity, diabetes, and sleep apnea. It is important to think of these diagnoses as manifestations of a system out of balance. All of these diseases can stay concealed for some time, after which they become more evident and more difficult to treat. One of Your Health Forum’s cornerstone themes is that optimal health (the behavioral, structural, and environmental factors) prevents disease development. In a state of imbalance, medications have only a minimal effect compared to returning toward the balance. I hope to convince you that the first step toward health is one of attention and awareness by getting checked if you think you might have a risk for hypertension.

 

Outline

1.  Epidemiology of Hypertension, the Silent Killer

2.  Pathophysiology of Hypertension

3.  Risk Factors for Hypertension

    a.  Obesity and Adiposity

    b.  Diabetes

    c.  Sleep Apnea

4.  Developing an Action Plan for Hypertension

 

Epidemiology of Hypertension, the Silent Killer

In the United States, as much as 20% of the population (15% of women; 20% of men) are unaware of their hypertension diagnosis (CDC). High blood pressure worsens and changes the body over time. Many people who have it are not aware of the condition until they get checked in the clinic or have a complication related to it (heart disease and stroke). There are usually no symptoms until then, and for this reason, it is often referred to as the “silent killer.” In 2018, an estimated half a million people died from hypertension-related causes in the United States.

The prevalence of hypertension is not equally distributed across the United States. The highest rates are noted to be in the southeast. These are the same areas that struggle with diabetes, obesity, and poverty. Unfortunately, African Americans are disproportionately affected by all of these conditions and deserves attention. February is also African American History Month.  African American (and Latinx) adolescents are at risk for severe obesity (two-fold higher rates) compared non-Hispanic whites (13% compared to 4.9%).

 

The southeastern United States have the highest prevalence of adults living with hypertension
Taken from CDC.gov section hypertension

 

Hypertension Pathophysiology and Risk Factors

Physicians cannot always determine the exact reason for high blood pressure in every patient. In fact, no cause can be identified 90-95% of the time.  The terms “primary” and “essential’ sometime precede the diagnosis of hypertension, suggesting that it is an isolated disease state, when no secondary causes can be determined.

However, multiple risk factors are known to escalate blood pressure. When these risk factors are addressed and improved, the blood pressure levels fall.

It may be more accurate to describe hypertension as a physiologic imbalance. Hypertension is the output of a compensatory process in a strained system. If correcting risk factors (other than age), such as weight optimization, exercise, and stress management mitigates the condition, then high blood pressure always is “secondary.” This has implications on how we can best address it. Keep in mind, that it is estimated that only about one in four people with hypertension are in a target blood pressure range on medications. Getting the system back into balance works better than any medication.

 

 

Blood pressure physiology

Blood pressure correlates to cardiac output (the propelling force of the heart) and peripheral vascular resistance (the resistance that vessels like arterioles have) .

The process is regulated by multiple hormones in multiple systems. Within the kidneys, a hormone known as renin is released when pressures out of the kidney vascular bed decrease (renal afferent arteriolar flow). The renin converts angiotensinogen into angiotensin I. This is then activated by angiotensin converting enzyme (ACE) into angiotensin II. This substance causes a constriction of those vessels and an increase in blood pressure. The blood flow returns to an increased level in these afferent arterioles.  Aldosterone is also secreted by the adrenal glands and acts to keep salt and water in the system.

Blood pressure is a physiologic process in the body regulated by physical (changes in vascular lining with aging, obesity), molecular (neurotransmitters like epinephrine, hormones like aldosterone, cortisol, thyroid hormone), and chemical (Na+, cytokines, etc) interactions.

 

 

Risk Factors of Hypertension

There are various risk factors to high blood pressure. It is useful to explore any potential risk factor when addressing blood pressure control, both preventatively and for treatment.

Below are some of the risk factors:

  • Excess adipose tissue

  • Inactive lifestyle

  • Excessive salt in the diet  (usually much higher than typical use)

  • Rare genetic conditions or hormonal conditions

  • Environmental factors (diet, food availability, physical inactivity)

  • Behavior

  • Smoking

  • Alcohol consumption, illicit drugs (stimulants)

  • Medications (steroids, non-steroidals, some anti-psychotics)

 

The Diagnosis of Hypertension

High blood pressure diagnosis takes place when patients attend regular medical checkups. When blood pressures reach dangerously high levels, patients can experience headaches, dizziness, and blurred vision, but most of the time people with hypertension do not have symptoms.   Here is an online symptom checker https://ada.com/conditions/essential-hypertention.  Hypertension is the leading reason for death, disabilities, heart care, and cardiovascular conditions:

  • Stroke, 700,000 occur each year in the United States

  • Heart disease and heart failure

  • Aortic and peripheral arterial disease

 

High Blood Pressure Readings

High blood pressure readings formed by two numbers, the systole (upper number) and the diastole (lower number). The systole is the highest pressure of the heart caused when the left ventricle contracts; diastole is the lowest pressure of the heart, when the upper chambers of the heart (atria) expand. The blood pressure readings correlate to the amount of pressure required by the heart to propel the blood in the setting of one’s body. The pressures will vary based on demand; but still, on average, the blood pressure levels remain less than 120 systolic in a well-functioning system.

In 2017, the American Heart Association and American College of Cardiology lowered the cut-off for high blood pressure to 130/80 mmHg and higher.  Before 2017, pressures greater than 140 systolic were considered high. Blood pressure between 120 mmHg systolic and 129 mmHg systolic are now consider elevated and fall in the category of “pre-hypertension.” The recommendations place a strong emphasis on early detection and risk factor modification.

Blood Pressure

Systolic levels

  • <120         Normal

  • 120-129    Elevated (Pre-hypertension)

  • 130-139    Hypertension Stage I

  • 140-179    Hypertension Stage II

  • >180         Hypertension crisis

Note: Diastolic pressure can sometimes be high as well in obesity, alcohol, and other causes of diastolic heart disease.

Risk Factors of Hypertension

1. Obesity: The Link to Systemic Dysfunction and Hypertension

For many years obesity was regarded only as a health risk factor rather than a disease entity. What occurs in obesity is a multi-systemic process of inflammation, increased blood volume, hormonal dysregulation. Obesity is a disease state, characterized by decompensations and harm. Obesity is a significant risk factor for high blood pressure, potentially comprising 65-75% of the risk in primary hypertension. Obesity increases blood volume and pressures on the blood return to the heart (or preload). Increased adipose (fat) tissue around the kidneys can activate the renin-angiotensin-aldosterone system and increase sympathetic (epinephrine) activity. Both of these changes increase blood pressure.

The heart compensates by remodeling to increase the cardiac output to overcome increased pressures. Studies performed on patients after gastric bypass surgery-related weight loss have shown a reduction in blood pressure correlated with a reduced left ventricular contractility (or cardiac output) and a shift toward parasympathetic cardiovascular control (less epinephrine).

Here is a summary of the compensation of obesity and how it leads to hypertension:  “Obesity….”

  • Activates the renin-angiotensin-aldosterone system

  • Increases sympathetic activity

  • Causes insulin and leptin resistance

  • Causes Endothelial dysfunction

 

I refer to the myriad health conditions associated with obesity as the “Orbit of Obesity.” Below are some conditions which accompany obesity, increasing in prevalence with increased weight. If you are managing

 

 

The Orbit of Obesity: High blood pressure is seen with obesity
Clockwise Around the Orbit: Stroke (orange), High blood pressure, Diabetes mellitus, Sleep apnea, Heartburn (and other GI dysfunction), Osteoarthritis, Gout, Heart Disease, High Triglycerides, Gallstones, Liver disease. Not pictured: Vascular disease and inflammation

 

 

 

waist circumference

 

Obesity and Adiposity

Adipose (fat) stores have an active effect on the endocrine system, not just the storage of potential energy. The hormone adiponectin is produced by the adipose tissue. Possibly as a consequence of oxidative stress, the hormone underproduced in an excess state of adipose tissue. It has been shown to be a biomarker of hypertension, with an inverse correlation seen (lower adiponectin levels associated with more hypertension).

Adiposity can be measured by waistline circumference measurements. Too much fat around the /waist is more than a 40-inch girth for men (102cm) and a 35-inch (88cm) girth for women. Below are some of the effects of this increased adipose tissue.

An excess of body weight can increase the risk of diabetes mellitus—the more in excess the body fat patients carry. Women with excess visceral (around internal organs) fat are more likely than men to develop diabetes, heart failure, and have diastolic dysfunction. It may be due to hormonal and body fat composition changes after menopause. Visceral fat is associated with insulin resistance.

The adipose tissue can cause further problems on other organs such as the kidney, cardiac, and vascular functions operating through a weak immune system and increased level of inflammation. Obesity contributes to hypertension from various influences such as food consumption, genetics, and environment. The Framingham Heart Study advises that a 5% weight gain increases high blood pressure by 30% over four years.

Other associations of increased adipose tissue:

  • Metabolic abnormalities, insulin resistance, and hypertriglyceridemia are associated with upper body fat and high blood pressure.

  • Insulin resistance prompts action on the small blood vessels that cause high blood pressure.

  • Hypertriglyceridemia can increase high blood pressure, and this slight increase can increase the risk of coronary artery disease.

 

3. Diabetes

Diabetes is a condition of impaired glucose metabolism. More than 9% of the global adult population has diabetes, a number that is expected to increase to 11% in 25 years.

In diabetes, the glucose in the blood is unable to be efficiently metabolized. This leads to uncontrolled glucose levels in the blood. High blood glucose unleashes oxidative stress damage to the vascular system and gradually impairs it. This leads to end-tissue damage and eye injury (diabetic retinopathy), peripheral nerve injury (diabetic neuropathy – from damage to the vessels to the nerves) and cardiovascular complications.

People with diabetes are more prone to hypertension than those without diabetes. People with type 2 diabetes and hypertension have a higher risk of other cardiovascular diseases and increased mortality. That is because the blood vessels are not able to protect the vascular organs from harm.

The co-association of hypertension and diabetes mellitus does increases with age. People with hypertension have a 2.5 time likelihood of developing type 2 diabetes. An estimated two-thirds of diabetics also have hypertension.  These two joint conditions raise the probability of other cardiovascular difficulties:

  • Coronary heart diseases

  • Ventricular hypertrophy

  • Congestive heart failure

  • Stroke

 

A little further in the pathophysiology of diabetes…

Diabetes leads to an increased secretion of glucagon (causing a paradoxical increases of blood glucose from glycogenolysis), impaired insulin production because of beta-islet cell destruction in the endocrine pancreas, and resistance of insulin function from ceramides which elicit inflammation-induced insulin resistance in the excess adipose tissue. These higher levels of glucose in the blood exert oxidative stress and cause a cascade of hormonal, neurotransmitter, and cytokine imbalance which leads to multi-system damage.

3. Obstructive Sleep Apnea and Hypertension

Obstructive sleep apnea is a risk factor for hypertension. Obstructive sleep apnea is a growing problem for the aging population and those who are obese.

Obstructive sleep apnea symptoms are:

  • Gasping during sleep

  • Headaches in the morning

  • Excessive daytime sleepiness

  • Loud snoring

This sleep-related breathing disorder is related to obstructed upper airways during sleep. Fifty percent of those with obstructive sleep apnea also have hypertension. Obstructive sleep apnea leads to hypertension by chronic intermittent hypoxia. If there is significant enough apnea (no breathing) or hypopnea (decreased inspiration), then there can be no gas exchange, so oxygen levels drop in the blood for periods of time during sleep. The blood vessels narrow, restricting blood flow, increasing pressure in the lung circulation. The hypoxia leads to high blood pressure and fast heart rates mediated by increased sympathetic tone (I.e. increased epinephrine release).

Anyone with hypertension who is overweight or obese should consider a sleep study to determine if significant sleep apnea exists. Additionally, any patient who has difficult to control blood pressure (on two or more medications) should have a screening sleep apnea test to ensure that it is not a treatable cause.

 

 

Developing An Action Plan for Hypertension

Here are some recommendations in “wholistically” addressing high blood pressure:

 

Counseling, Mindset, and Exercise:

  • Lark provides support services and coaching to help combat cardiovascular disease https://www.lark.com/blog/coronavirus-and-hypertension/.

  • Here is a physical activity calorie counter calculator from the American Council on Exercise ACE Fit | Physical Activity Calorie Counter (acefitness.org).

  • Exercise is an essential part of your hypertensive treatment and recovery. Exercise improves the vascular wall and helps with insulin resistance, and can help manage pro-inflammatory cytokines. Regular, daily exercise for 30 to 60 minutes is recommended.

  • Be aware of stress triggers. Stress can spike blood pressure levels by activating the nervous system to release vasoconstricting hormones. Practice mindfulness and seek help for addictions.

Diet Optimization:

  • Try the DASH eating plan offered by The National Heart Lung and Blood Institute. Find out more here to get started Getting Started on DASH | NHLBI, NIH.

  • Intermittent fasting can help decrease high blood pressure and improve overall cardiovascular health, such as diabetes and obesity. Intermittent fasting may reduce oxidative stress and optimize circadian rhythms and ketogenesis. 

  • A natural diet with low processed foods can be quite effective in weight optimization.

Blood Pressure Control:

Screen for Sleep Apnea:

Medications and Substance Abuse:

 

Summary

Your high blood pressures are a window to your vascular system. They do not occur in a vacuum, rather they are related to systemic risk factors that lead to an adjustment of increased blood pressures.  Accordingly, early identification and assessment for risk factors may reduce harm. Nevertheless, some people may require medications. With attention to the ways in which one may improve blood pressure by reducing risks, a person may potentially benefit from not only blood pressure reduction but improved functioning of the body found in optimal health.

 

 

 

 

Further Reading and References:

About Christopher Cirino 122 Articles
I am a board certified physician trained in infectious diseases and internal medicine. This site will feature health issues as they relate to infectious diseases, behavior and finding wellness.

1 Comment

  1. This is quite an in-depth look into hypertension. I believe this information will help many people in the United States and across the globe, given that this disease is a leading cause of death worldwide. Your post can certainly boost prevention and health promotion.

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