How Beta Blockers Affect Blood Sugar

Beta blockers are drugs used to treat high blood pressure (hypertension), abnormal heart rhythms, tremors, and anxiety. They are often used to reduce stress on the blood vessels and heart.

However, beta blockers can result in fluctuating blood sugar levels. In that case, the convenience of prescribing beta blockers to a person with a metabolic disorder having both high blood sugar and high blood pressure remains debatable.

How Beta Blockers Work

Beta blockers, also known as beta-adrenergic blocking agents, are a class of drugs that block the release of the stress hormones, adrenaline and noradrenaline, in certain parts of the body (1).

As a result, your heart rate slows, simultaneously reducing the force at which blood is pumped around the body. Therefore, it is used in the treatment of angina, cardiovascular problems, and heart arrhythmia. It is also used as blood pressure medication to reduce the risks of hypertension-related complications.

Beta blockers also block your kidneys from producing angiotensin II, which helps reduce blood pressure by relaxing and widening the blood vessels, causing an easy blood flow.

Normally, for hypertension, beta blockers are given along with other medicines such as ACE inhibitors and/or calcium channel blockers.

Effect of Beta Blockers on Blood Sugar Levels

To understand how beta blockers affect our blood sugar levels, it is important to learn about glucose management first.

Blood Glucose Management

In response to high glucose levels, the hormone GLP-1 is released from the intestine, which signals the beta cells in the pancreas to release insulin. This occurs in two phases: a rapid first phase followed by a delayed second phase.

Insulin acts on three major organs—the liver, muscles, and fat tissue—to increase glucose uptake and prevent the liver from forming new glucose. Once the insulin reaches the target cells from the pancreas, it binds to the receptors on the outside of the cells. This sets off a signal on the inside of the cell, which initiates the following chemical reactions:

• Increase in the number of glucose-transport proteins to help bring glucose into the cells
• Increase in the number of enzyme proteins that help breakdown and use glucose

Essentially, the liver, muscle, and fat tissues are important sinks where glucose is stored. Therefore, anything that interferes with the delivery of glucose to these tissues can unbalance blood glucose levels.

Can Beta Blockers Cause Low Blood Sugar?

Beta blockers block the release of insulin by interacting with nerve signals to the pancreas and thus lower its levels. This can cause hyperglycemia, or high blood sugar.

Studies have stated that a combination of beta blockers and thiazide diuretics, used to lower blood pressure in hypertensive people, can increase the risk of developing diabetes by 20%. The risk is higher if you have a familial history of diabetes, impaired glucose tolerance, or obesity (2).

Self-management for diabetes can help tackle the fluctuations.

Even though beta blockers are known to cause hyperglycemia, they can also cause or exacerbate hypoglycemia in some individuals. However, this is only true for people who are diabetic and take insulin or sugar-reducing medicine such as sulfonylurea, atenolol, and propranolol.

The problem with beta blockers is that they completely mask the signs of hypoglycemia, such as a slow heartbeat, while also delaying recovery.

Common Side Effects of Beta Blockers

The most common side effects of beta blockers include the following:

• Cold feet and hands, particularly in older people
• Slow heartbeat
• Low blood pressure
• Fluid retention
• Fatigue
• Weakness and dizziness
• Sleep disturbances and unusually vivid dreams
• Erectile dysfunction

People with asthma and Raynaud’s disease may have more pronounced side effects.

Who Shouldn’t Take Beta Blockers?

People with the following conditions should be wary of taking beta blockers, and consult a healthcare professional first:

• Low blood pressure
• Bronchospasm
• Bradycardia (slow heartbeat)
• Uncontrolled heart failure
• Asthma
• Lung diseases
• Diabetes

Additionally, those with a history of cocaine abuse should avoid beta blockers.

Conclusion: Is It Safe to Stop Using Beta Blockers?

No, it is not safe to stop using beta blockers without proper medical assistance.

Never start on beta blockers without medical consultation, and do not stop taking beta blockers without consulting either. As your body gets used to it, a sudden cessation can cause palpitations, recurrence of angina pain, and a rise in blood pressure that could be fatal.

Medical Disclaimer

Dario Health offers health, fitness, and nutritional information and is designed for educational purposes only and should not be relied upon. The information provided might not be accurate, full, complete, or effective. Accordingly, it is not intended to be used for medical diagnosis or treatment or as a substitute for professional medical advice. You are strongly advised to consult your physician or qualified health professional regarding your condition and appropriate medical treatment. Individual symptoms, situations, and circumstances may vary.

Resources

1. https://www.bhf.org.uk/informationsupport/heart-matters-magazine/medical/drug-cabinet/beta-blockers
2. https://cardiab.biomedcentral.com/articles/10.1186/s12933-019-0967-1

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