How diabetes affects blood pressure and how to treat these conditions

Key takeaways:

• Diabetes can cause atherosclerosis, which narrows the blood vessels, leading to high blood pressure (hypertension). 
• People with diabetes are twice as likely to develop high blood pressure than those without. 
• A healthy lifestyle and a low-salt diet are key to managing hypertension. Also, reducing your intake of sugar-sweetened beverages can help lower your blood pressure. 
• Certain teas, like green tea, black tea, hibiscus tea, olive leaf tea, and chamomile tea, can be beneficial for regulating blood pressure. 

Over one billion adults aged 30 to 79 have hypertension, and most live in low and middle-income countries. Similarly, diabetes mellitus affects roughly 422 million people worldwide and causes about 1.5 million deaths each year. These statistics show that diabetes and hypertension (high blood pressure) are both common health conditions found in populations across the globe.

Hypertension is a blood pressure reading of 140/90 millimeters of mercury (mm Hg) or higher. The first number is the systolic pressure, while the second is the diastolic pressure. Systolic is the pressure in the blood vessels as the heart contracts, and diastolic is the pressure in the vessels when the heart relaxes between beats. 

This article explores the link between diabetes and hypertension and highlights how to manage and prevent hypertension if you have diabetes. 

Can diabetes affect blood pressure?

Diabetes can affect your blood pressure. Over time, uncontrolled high blood glucose can lead to the development of atherosclerosis.

Atherosclerosis is the buildup of fat, cholesterol, and other substances inside and on the artery walls. This buildup is known as plaque, and it narrows the arteries. When the arteries become narrow, the heart has to work harder to circulate blood throughout the body, leading to high blood pressure.

The link between diabetes and hypertension

Diabetes and hypertension often overlap. As a matter of fact, people with diabetes are twice more likely to have hypertension than those without.

According to a study published in the Canadian Journal of Cardiology, the major cause of death in patients with diabetes is cardiovascular disease, and hypertension worsens it.

Unsurprisingly, diabetes and hypertension also share similar risk factors. Their risk factors include: 

• Obesity 
• A sedentary lifestyle 
• Kidney disease 
• An unhealthy diet 
• Sleep disorders 

What is the normal blood pressure for a person with diabetes?

There is no single optimal blood pressure level for everyone. But individuals with diabetes should aim to keep their blood pressure around 135/85 mm Hg. 

For those at increased risk of cardiovascular diseases, blood pressure that is closer to, but not above, 130/80 mm Hg is recommended.

Does cutting out sugar lower blood pressure?

Reducing your sugar intake can help lower your blood pressure. Sugars, especially those used in processed food, can contribute to hypertension.

High-fructose corn syrup (HFCS) is a mixture of 55% fructose and 45% glucose and is commonly used as a sweetener in soft drinks. The fructose in HFCS raises blood uric acid levels, which inhibits the production of nitric oxide. Nitric oxide deficiency leads to the narrowing of blood vessels and hypertension. 

The results of a study involving 810 adults in the United States show that consuming less sugar-sweetened beverages can reduce blood pressure.

Foods that can lower blood pressure

The low-salt Dietary Approaches to Stop Hypertension (DASH) diet may help lower blood pressure.

The goal of the DASH diet is to help you make dietary changes such as:

• Limiting your sodium (salt) intake to 2,300 mg a day
• Reducing saturated fat to less than 6% of daily calories and total fat to 27% of daily calories 
• Consuming low-fat dairy products like skimmed milk and fat-free cottage cheese
• Using monounsaturated oils such as olive or canola oil  
• Choosing whole grains, such as brown rice and oats over white flour or pasta products 
• Choosing healthy protein sources like fish and skinless poultry 
• Eating nuts, seeds, or legumes (dried beans or peas) daily 
• Snacking on fresh fruits and vegetables every day 
• Getting less than 18% of your daily calories from protein 

You can calculate your daily calorie requirements to know how many calories your body needs daily to maintain your weight. If you want to know how many calories each individual food on your plate contains, you can use a food calorie calculator tool. 

How to know you have high blood pressure

High blood pressure usually doesn’t cause any symptoms. Regularly checking your blood pressure is the standard way to know if it’s high. 

However, if your blood pressure gets as high as 180/120, it can cause symptoms. Symptoms of very high blood pressure may include:

• Severe headaches 
• Chest pain 
• Dizziness 
• Difficulty breathing 
• Nausea and vomiting 
• Blurred vision
• Anxiety 
• Confusion 
• Buzzing in the ears 
• Nosebleeds 
• Abnormal heart rhythm 

Untreated hypertension can cause other health conditions like kidney disease, heart disease, and stroke.

How to treat hypertension in people with diabetes

There are two ways to treat hypertension if you have diabetes — embracing positive lifestyle changes and using medications. Medications are used when lifestyle changes aren’t enough. 

Lifestyle changes

According to the World Health Organization (WHO), the following lifestyle changes can help lower high blood pressure:

• Losing weight 
• Being physically active 
• Quitting tobacco 
• Eating a healthy, low-salt diet 

Medications

If modifying your lifestyle doesn’t keep your blood pressure below 140/90, your doctor may prescribe any of these medications. 

• Angiotensin-converting enzyme (ACE) inhibitors: ACE inhibitors widen the blood vessels by inhibiting the production of angiotensin 2, a hormone that narrows the vessels. This reduces the stress on the heart and consequently lowers blood pressure. 
• Angiotensin-2 receptor blockers (ARBs): Like ACE inhibitors, these drugs widen the blood vessels, but through a different process. They do not prevent the production of angiotensin 2; instead, they stop it from acting. 
• Beta-blockers: Beta-blockers are medications that slow the heart rate by blocking the effects of hormones like adrenaline (a hormone that can make your heart race).
• Calcium channel blockers: Calcium channel blockers prevent calcium from entering the cells of the heart and blood vessels. This relaxes the heart and blood vessels, reducing blood pressure.
• Diuretics: Diuretics are medications that help your kidneys get rid of excess water and salt — which ends up making you urinate more. The elimination of excess fluid reduces the workload on your heart.

Teas you can drink to lower blood pressure fast

The following teas can have a positive effect on high blood pressure. 

1. Green and black tea

The results of a 2020 review of five studies suggest that regularly drinking green or black tea may be beneficial for managing hypertension.

Green and black teas are made using the leaves of the same plant — Camellia sinensis. The only difference between both teas is that leaves used to make black tea are exposed to air, which turns them dark brown-black through a process known as oxidation. 

2. Hibiscus tea

Research-based evidence also suggests that hibiscus tea, also called zobo can significantly lower blood pressure. Hibiscus tea is made by boiling the flower of the hibiscus plant or steeping it in cold water overnight. You can add ginger, cinnamon, and other spices for flavor. 

3. Olive leaf tea

As the name implies, olive leaf tea is made from the leaves of the olive tree. To prepare it, you steep the leaves in hot or warm water. 

A 2017 clinical study involving 31 participants found that olive-leaf herbal tea can have a favorable impact on blood pressure.

4. Chamomile tea

Chamomile has a long history of medicinal uses. The plant possesses antioxidant, anti-inflammatory, and anti-hypertensive properties, to name a few.

You can make chamomile tea from the dried flowers of the plant. 

How people with diabetes can prevent high blood pressure

If you have diabetes and you’re worried about developing hypertension, you can help prevent it by living healthy, which entails: 

• Eating a healthy diet: Limit the amount of sodium in your food and eat foods rich in potassium. An ideal way to do this is by following the recommendations of the DASH diet. 
• Getting regular exercise: Try to exercise as much as possible. Exercise can help you maintain a healthy weight and lower your blood pressure. 
• Maintaining a healthy weight: Obesity is a risk factor for hypertension. Therefore, portion control and exercise are necessary. 
• Limiting alcohol: Excess alcohol can raise your blood pressure and lead to weight gain. People assigned male at birth shouldn’t have more than two drinks per day, while people assigned female should stick to one. 
• Not smoking: Smoking increases your blood pressure and increases your risk of a heart attack and stroke. If you’re a smoker, discuss how you can quit with your healthcare provider. 
• Managing stress: Effective stress management can improve your emotional and physical health and lower high blood pressure. Stress management techniques include meditation and breathing exercises.   

Managing diabetes and hypertension with a medical team

Managing diabetes and hypertension with a medical team can be difficult for some people, but not impossible. 

You may have to self-monitor your blood glucose and blood pressure using home test kits and report the results to your healthcare team. 

Consult your doctor before trying a herbal tea for hypertension, especially if you’re on any medication. This is because the tea may interact with your drug, i.e., heighten or reduce its effects.