Diabetes and High Blood Pressure: What Doctors Need You to Know

Understanding diabetes and high blood pressure

Diabetes and high blood pressure are very common conditions. According to a 2020 report by the Centers for Disease Control and Prevention, 34.2 million Americans, or more than one in 10, have diabetes, and an additional 88 million have pre-diabetes. Nearly half of U.S. adults have high blood pressure, and only one in four have the condition under control.

Separately, diabetes and high blood pressure can cause problems, but together they can be a deadly duo. According to the American Diabetes Association (ADA), two of three people with diabetes have high blood pressure or take medication to lower it.

Both high blood pressure and diabetes are independent risk factors for heart disease, and when they happen together, your risk is even greater. Heart disease is the leading cause of death among people with diabetes.

“Maintaining normal blood pressure is a critical part of heart disease prevention in patients with diabetes,” says Bryan Jiang, MD, assistant professor of endocrinology, diabetes, and metabolism, and internal medicine at Baylor College of Medicine in Houston.

Here’s an in-depth look at how the diabetes and high blood pressure are connected and what you can do to reduce your risk of more serious health problems in the future. (Here’s a look at the silent diabetes complications and how to avoid them.)

What is diabetes?

When people say “diabetes” they usually mean type 2 diabetes, which tends to develop in adulthood due to a combination of genetic and lifestyle factors. Exercise, an active lifestyle, and healthy eating can prevent or delay a type 2 diabetes diagnosis in people who are prone to the disease. Type 1 diabetes, on the other hand, is an autoimmune disease that is often diagnosed in children or younger people, and can’t be prevented with lifestyle changes.

“Type 2 diabetes is the more common form, and is caused by the body becoming resistant to the effects of insulin, coupled with a second problem that involves the inability for someone to make enough extra insulin overcome that resistance,” says Robert A. Gabbay, MD, chief scientific and medical officer for the ADA.

Insulin plays a key role in the disease progression and treatment.

“Insulin is a hormone responsible for allowing cells in the body to take up glucose [sugar] from the bloodstream,” says Dr. Jiang. “Patients with type 2 diabetes have elevated blood glucose levels because the insulin being produced is no longer effective.” Instead, the sugar remains in the blood instead of being used by the body. (These are insulin resistance symptoms to know.)

High blood sugar is toxic. Over time, it can damage blood vessels and organs, including the heart and kidneys, Dr. Jiang says. (Learn these life-saving glucose facts.)

High blood sugar can be diagnosed with a blood test. Physical inactivity, poor diet, and weight gain are linked with insulin resistance and type 2 diabetes, so lifestyle changes—namely more exercise and healthy eating—can help get blood sugar into the healthy range.

People with type 1 diabetes need to check their blood sugar frequently and use insulin to survive, while people with type 2 diabetes may be able to control their blood sugar with diet and exercise, oral medications, or insulin. (These are some of the life-saving things to do when you’re living with diabetes.)

About 30 percent of people with type 1 diabetes and 50 to 80 percent of people with type 2 diabetes have high blood pressure.

What is high blood pressure?

“Blood pressure is a measurement of the force on the walls of a person’s arteries by the circulating blood,” Dr. Jiang says. “It is primarily affected by the stiffness of the blood vessels and how hard the heart is working.” It’s measured by taking the pressure when your heart beats (systolic, the top number) and when it rests (diastolic, the bottom number). Normal blood pressure is anything lower than 120/80 mm Hg.

“Hypertension [high blood pressure] has a variety of causes, but fundamentally the ‘tone,’ or the inherent pressure around blood vessels, is heightened,” Dr. Gabbay says. “There can be a variety of reasons,” he says.

Although doctors don’t know exactly what causes high blood pressure, it may be linked to diet, especially too much salt, as well as lack of physical activity, smoking, and too much alcohol. (Avoid these high blood pressure foods.)

High blood pressure makes the heart work harder to pump, which can wear it out over time, and damages artery walls, narrowing the blood vessels.

“If you think about the vessels being a tube, too much fluid in the tube or constriction of the tube can lead to higher pressure,” Dr. Gabbay says. Known as the “silent killer,” hypertension usually has no symptoms and is only diagnosed by routine checks by your doctor.

“Over time, persistently high blood pressure leads to an increased risk of multiple conditions including stroke, kidney failure, heart failure, and heart attacks,” Dr. Jiang says. You may need to take medications and develop healthier habits to control it, as well as use a home blood pressure monitor.

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The link between diabetes and high blood pressure

Both high blood pressure and type 2 diabetes may, in part, have similar lifestyle causes.

“Multiple studies have clearly shown that having diabetes or high blood pressure will raise your risk for having the other condition; however, these studies were not designed to prove that one condition directly led to the other,” Dr. Jiang says. “Both conditions often co-exist since they share similar common risk factors including obesity, poor diet, chronic inflammation, and a sedentary lifestyle,” he says.

But once you have one, you will be at greater risk of the other. “It works both ways: People with type 2 diabetes are more likely to have hypertension, and those with hypertension are more likely to have type 2 diabetes,” Dr. Gabbay says. (These are the diabetes myths that may hurt your health.)

What’s going on in the body when this happens? “As insulin resistance increases and blood glucose levels rise, it can cause arteries to harden—as this occurs, blood pressure can rise,” says certified diabetes educator and registered dietitian Erin Palinski-Wade.

According to the American Heart Association (AHA), there’s a link between insulin resistance and high blood pressure.

There may be some other connections as well. “Diabetes can lead to complications in the kidneys, which play a key role in the regulation of blood pressure,” Dr. Jiang says. “In addition, we do know that long-term damage from diabetes can lead to stiffening of the blood vessels, which is linked to and can exacerbate high blood pressure.”

The negative effects

Nearly 70 percent of people over 65 with diabetes will die of heart disease, according to the AHA. “When together, these conditions exacerbate each other,” Dr. Jiang says. “Patients with both diabetes and high blood pressure are up to four times as likely to develop heart disease when compared to those without either condition,” he says.

How exactly do the two conditions raise your heart disease risk? “Both do so independently,” Dr. Gabbay says. “Hypertension puts a strain on the heart—imagine having a pump against higher pressure in the tube. Type 2 diabetes raises the risk in a variety of ways through increasing the risk of high blood pressure, increasing bad cholesterol levels, and through direct effects on the blood vessels,” he says. (Here’s what doctors do themselves to lower high cholesterol.)

And it’s not just the heart itself you have to worry about. “This combination [of diabetes and high blood pressure] increases the risk of heart disease and also worsens circulation, which can have a negative impact on all of the organs in the body including the kidneys, eyes, and even the brain,” Palinski-Wade says.

Can you treat them both at the same time?

Yes, fortunately, diabetes and high blood pressure have similar treatments, particularly when it comes to lifestyle improvements. “Both conditions are helped by exercise and appropriate diet,” Dr. Gabbay says.

In addition, medications can help with both conditions, and can often be used in combination. “There are medications that treat both diabetes and high blood pressure,” Dr. Gabbay says. “Many of them work synergistically to lower cardiovascular risk, and in general treatment of one doesn’t necessarily worsen the other—if anything it helps.”

A 2019 study in the journal Hypertension found that people with diabetes who lowered their blood pressure at or below 130/80 had fewer heart attacks and strokes.

How diet can help

If you have diabetes with high blood pressure, a dietitian or diabetes educator can work with you to figure out changes to your diet that will work to treat both conditions. For example, “focusing on fiber can be key to improving diabetes and high blood pressure,” Palinski-Wade says.

Eating to prevent blood sugar spikes

“Eating foods rich in fiber slows down how quickly carbohydrates are converted into sugar, which can prevent spikes in blood sugar levels. In addition, soluble fiber in foods can help to carry cholesterol out of the body, helping to prevent plaque from building in the arteries and hardening them. As arteries remain more flexible, blood pressure remains lower,” Palinski-Wade says. (These are the worst diabetes foods.)

Adding more plant-based fats in place of animal fats in the diet can help as well. “A decrease in saturated fat may improve insulin resistance and blood lipids [cholesterol],” Palinski-Wade says. “Specifically, adding more plant-based fat from fresh avocado may be beneficial to managing diabetes while promoting heart health,” she says.

Eating to lower high blood pressure

Avocados are high in healthy fats and fiber yet low in carbs, and are cholesterol and sodium (salt) free.

In general, you’ll want to avoid salty foods in general to keep blood pressure low. “Avoiding processed foods that are often high in salt content” is advised, Dr. Jiang says. Talk to your dietitian or doctor about the DASH diet (Dietary Approaches to Stop Hypertension), which emphasizes vegetables, fruit, whole grains, and low-fat dairy foods while cutting out saturated fat and added sugar.

“Reducing added sugar in the diet to less than 10 percent of total calories can also help,” Palinski-Wade says. “Excess added sugar can increase insulin resistance, worsening diabetes. In addition, diets high in added sugar can increase blood lipids such as triglycerides and increase the risk of heart disease.”

(These are the foods that help lower high blood pressure.)

How exercise can help

Even if you’re not going to join a gym, just a bit more exercise can help set you on the road to lower blood pressure and diabetes management. “By simply taking time to walk for even 10 minutes every day you can improve circulation and reduce insulin resistance,” Palinski-Wade says. “Those behaviors together will improve blood glucose management and blood pressure,” she says. (Here’s the best exercise for high blood pressure.)

You can gradually work up to a larger fitness goal. “Currently, the American Heart Association recommends at least 150 minutes a week of moderate-intensity aerobic exercise, which includes activities like walking or swimming,” Dr. Jiang says. “Aerobic exercise has been shown to both lower blood pressure and lower blood sugar levels in diabetics,” he says.

Palinski-Wade also recommends a mind/body practice such as meditation. “Taking time to reduce stress through deep breathing or meditation can be incredibly beneficial to health,” she says.

Palinski-Wade adds: “Reduced stress can improve blood sugar levels and blood pressure. In addition, lower stress may improve sleep quality, which in turn further improves insulin resistance, stress hormones, and blood pressure levels.”

How weight loss can help

Both a healthy diet and exercise can help reduce high blood pressure and control blood sugar in people who have type 2 diabetes.

“In patients with excess weight, weight loss as small as 3 to 5 percent of body weight was shown to improve blood pressures, because the heart does not have to pump as hard after weight reduction,” Dr. Jiang says. “Losing excess weight has also been shown to slow the progression of pre-diabetes to diabetes in at-risk patients.” (Try this type 2 diabetes diet to lose weight.)

Weight loss can benefit those who already have diabetes as well. “For many people with type 2 diabetes who have obesity, weight loss can make a big difference in both their diabetes, blood pressure, and ultimately risk of heart disease,” Dr. Gabbay says.

Bad habits to avoid

In addition to starting healthy behaviors, you’ll also want to curb some unhealthy habits to avoid high blood pressure with diabetes. The first of is to quit smoking.

“If you smoke, your risk [of heart disease] increases exponentially,” Palinski-Wade says. “Smoking can also further damage circulation, increasing the risk of damage to all of your organs.”

You’ll also want to make sure you’re getting seven to nine hours of sleep each night. “A good night’s sleep can impact everything from stress levels to appetite, metabolism, and even insulin regulation,” Palinski-Wade says. “If you don’t prioritize sleep, blood sugar and blood pressure can rise. In addition, a lack of sleep may make it more challenging to eat a balanced diet—lack of sleep increases hunger hormones—and exercise due to fatigue,” she says.

Although this can be difficult in our world today, Palinski-Wade suggests managing stress. “When stress levels are elevated, both blood sugar and blood pressure elevate,” she says. “Practicing stress management techniques [such as meditation or deep breathing, as mentioned above] can improve both diabetes and hypertension while reducing heart disease risk.”

Do you need medication?

“Lifestyle changes are usually the first line treatment for both conditions,” Dr. Jiang says. But if necessary, your doctor might look to medications to target certain blood sugar and blood pressure goals.

“Medications for diabetes range in complexity from daily oral treatments to multiple daily injections of insulin therapy,” Dr. Jiang says.

Although these glucose-lowering treatments don’t affect blood pressure directly, Dr. Jiang says some can have added benefits beyond improving blood sugar such as weight loss promotion and reducing the risk of heart attacks and stroke.

As for blood pressure medications, “Angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) are particularly helpful in patients with both diabetes and high blood pressure since they not only help control blood pressure, but also reduce the risk of kidney complications from diabetes,” Dr. Jiang says.

“Generally, most treatments for high blood pressure do not directly affect blood sugar management; however, drug interactions can exist and need to be considered,” he says.

Make sure your doctors know all the different medications you’re taking, so they can come up with the plan that’s right for you. (Here are important questions to ask about your prescription medications.)

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