Does metformin affect blood pressure?

In this article:

• What is considered high blood pressure?
• The consequences of high blood pressure
• The link between high blood pressure and diabetes
• Does metformin lower blood pressure?
• Metformin and cardiovascular health
• Other ways to manage blood pressure with diabetes
• The bottom line

In this article

• What is considered high blood pressure?
• The consequences of high blood pressure
• The link between high blood pressure and diabetes
• Does metformin lower blood pressure?
• Metformin and cardiovascular health
• Other ways to manage blood pressure with diabetes
• The bottom line

Metformin, a widely used medication for Type 2 diabetes, has been linked to several health benefits beyond managing glucose (sugar) levels. One benefit is how it might affect blood pressure. Studies show that metformin could help lower some people’s blood pressure, making it even more valuable as a diabetes treatment.

If metformin can help control blood pressure, it may provide an advantage in reducing the risks linked to heart disease. While not all research supports significant reductions in blood pressure, even small changes may positively affect cardiovascular health. Discuss the potential benefits with a healthcare provider if you or a loved one takes metformin.

What is considered high blood pressure?

High blood pressure, also known as hypertension, occurs when the force of blood against artery walls is too high. Blood pressure readings have two numbers: systolic (SBP) and diastolic (DBP). These are measured in millimeters of mercury (mm Hg).

Normal blood pressure:

• Systolic: Less than 120 mm Hg
• Diastolic: Less than 80 mm Hg

Elevated blood pressure:

• Systolic: 120-129 mm Hg
• Diastolic: Less than 80 mm Hg

Hypertension Stage 1:

• Systolic: 130-139 mm Hg
• Diastolic: 80-89 mm Hg

Hypertension Stage 2:

• Systolic: 140 mm Hg or higher
• Diastolic: 90 mm Hg or higher

Hypertensive crisis (emergency care needed):

• Systolic: Over 180 mm Hg
• Diastolic: Over 120 mm Hg

Symptoms often do not appear until blood pressure is dangerously high. Therefore, healthcare providers recommend regularly monitoring blood pressure. High blood pressure may increase the risk of serious health problems like heart disease and stroke.

RELATED: What is systolic vs. diastolic blood pressure?

The consequences of high blood pressure

Left uncontrolled, high blood pressure may lead to many health problems. One of the most important concerns is its effects on the cardiovascular system, as it may cause damage to blood vessels. Damaged blood vessels can make it harder for blood to flow effectively. This can result in vascular dysfunction, characterized by:

• Thickening of the arterial walls
• Reduced elasticity of arteries
• Increased risk of blood clots

These changes are often risk factors for problems with cardiovascular diseases, such as heart attacks and strokes. As high blood pressure makes the heart work harder to pump blood, an increased workload may weaken the heart and lead to heart failure.

Other major consequences of high blood pressure may include:

• Kidney damage
• Vision loss
• Cognitive decline
• Sexual dysfunction
• Metabolic syndrome

Key risk factors for high blood pressure involve lifestyle choices such as diet, exercise, and stress management. Monitoring blood pressure and managing risk factors may help prevent complications and improve quality of life.

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The link between high blood pressure and diabetes

High blood pressure and diabetes, especially Type 2 diabetes mellitus (T2DM), often occur together. Many diabetic patients experience elevated blood pressure due to increased insulin resistance and issues with glucose tolerance. 

Insulin resistance happens when cells in your body don’t respond well to insulin, causing higher blood glucose levels. Over time, problems with blood sugar may contribute to hypertension and diabetes.

Type 2 diabetes often leads to obesity, a major risk factor for high blood pressure. Excess body weight increases the workload on the heart and can cause blood pressure to rise. Poor glycemic control may further complicate the situation by damaging blood vessels, which can increase blood pressure levels.

Studies show that diabetes and high blood pressure together may raise the risk of cardiovascular diseases and kidney problems. Around 74% of adults with diabetes have systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥90 mmHg, or they are on medication to manage these conditions.

Does metformin lower blood pressure?

Some clinical studies suggest that metformin may lower blood pressure, but the effects are generally modest. In a meta-analysis involving nondiabetic patients, metformin treatment led to a slight reduction in systolic blood pressure, with an average decrease of 1.98 mmHg. Diastolic blood pressure did not show a significant change.

A separate clinical trial with nondiabetic hypertensive patients showed that while metformin led to a decline in diastolic office blood pressure, this decline was not significantly different from that observed with a placebo. The results suggest that metformin’s effects on blood pressure might be minimal for people without diabetes.

In patients with impaired glucose tolerance or obesity, metformin showed slightly more significant reductions in systolic blood pressure. Both groups taking metformin experienced a noticeable drop in their systolic blood pressure. The average drop was about 3 mmHg for those on only metformin, while for those on both metformin and insulin, it was around 5 mmHg. However, neither group had a significant change in the diastolic blood pressure.

The antihypertensive effects of metformin may be limited and vary depending on a person’s overall health condition.

Metformin and cardiovascular health

Metformin has been shown to have positive effects on cardiovascular health. It can lower various risk factors for cardiovascular disease, such as triglycerides and other lipids (blood fats). 

Researchers studied the effects of metformin on patients with high triglycerides and different levels of glucose intolerance. They found that metformin lowered triglyceride levels by an average of 38%, with 18 out of 30 patients showing significant improvement. Since high triglyceride levels are linked to heart disease, the study suggests that metformin could help improve heart health.

Studies show that people who take metformin have a lower risk of dying from any cause and a lower chance of getting cardiovascular disease than those who use insulin or other diabetes pills. One study found that people on metformin had a 7% lower risk of death compared to non-diabetics. In addition, metformin users had a 24% lower chance of developing cardiovascular disease compared to those on other diabetes therapies.

Other studies have reinforced the effects of metformin in reducing cardiovascular risks in non-diabetic patients. A small study showed it reduced heart-related problems in non-diabetic women with chest pain, suggesting it could be useful beyond diabetes. It has also been linked to better heart health and less inflammation in those who don’t have diabetes.

Other ways to manage blood pressure with diabetes

Managing blood pressure when you have diabetes is key to preventing complications like heart disease. Besides medications, several strategies exist to manage blood pressure with diabetes.

Lifestyle changes

• Diet: Following the DASH diet can lower systolic blood pressure by over 11 mmHg. This diet emphasizes fruits, vegetables, whole grains, and low-fat dairy.
• Exercise: Regular physical activity may help improve cardiovascular health and support weight loss. Aim for at least 30 minutes of moderate exercise most days.

Blood pressure medications

Medications like ACE inhibitors, ARBs, calcium channel blockers, and diuretics may help lower blood pressure. Each type targets different mechanisms to control blood pressure.

Quitting smoking

Smoking increases blood pressure and heart rate. Therefore, quitting smoking may help reduce these risks.

Stress management

Stress can elevate blood pressure. Techniques like meditation, deep breathing, and yoga may help manage stress levels.

These changes may complement medications like metformin to manage diabetes and blood pressure. Regular check-ups with your healthcare provider can also help fine-tune your treatment plan.

The bottom line

Metformin, a commonly used medication for Type 2 diabetes, also shows promise in lowering blood pressure. While its direct effects on blood pressure may be modest, it may contribute to lowering lipid levels and improving heart health. Metformin’s effects on blood pressure could benefit people with diabetes and hypertension. However, you should consult a healthcare provider to determine the best treatment option based on your overall condition.