Heart Disease and Diabetes: Causes, Symptoms, and Prevention
Key takeaways:
- People with diabetes are twice as likely to develop heart disease, a group of conditions that affect the heart and blood vessels.
- Understanding your lab values and monitoring these key health metrics with your healthcare provider can help you stay on top of heart disease prevention.
- Managing blood sugar, blood pressure, and cholesterol with medications and lifestyle changes can improve your diabetes management and your overall heart health.
Heart disease comes in many forms, from heart attacks and strokes to heart failure and arrhythmias (irregular heartbeats). One of the most common culprits is coronary artery disease, where the vessels that supply blood to the heart become narrowed or blocked. Similarly, peripheral artery disease can cause restricted blood flow to the arms and legs instead of the heart.
Diabetes is a risk factor for all of these conditions, but there are steps you can take to improve both your diabetes management and your heart health.
The link between diabetes and heart disease
Studies have shown that when blood sugar levels are high for a prolonged period of time, blood vessels can become damaged, reducing the amount of blood flow to vital organs like the heart or brain. This is part of the reason why people with diabetes are twice as likely to have heart disease or experience a stroke – and why blood sugar management can be crucial to preventing serious complications.
Even when blood sugar levels are being managed, other diabetes-related conditions can increase one’s risk of heart disease. High blood pressure, for example, can damage the walls of blood vessels and force the heart to pump harder, which weakens heart muscles.
High cholesterol is also a major risk factor for developing heart disease, especially heart attacks. Both LDL cholesterol and triglycerides can cause the formation of plaques (fatty deposits) that attach to blood vessels and thicken their walls, which is called atherosclerosis. This makes it difficult for blood to pass through, and severe blockages can lead to heart attacks and strokes.
Out of all the risk factors, studies have shown that high blood pressure is a major contributor to heart disease. Other contributors include high cholesterol, tobacco use, abdominal obesity, and diabetes. Together, these factors account for almost half of the total risk associated with developing cardiovascular disease.
The good news? Many of these conditions are both preventable and manageable. By recognizing the symptoms and keeping an eye on where you fall within target ranges for important lab values, you can be proactive about lowering your risk for heart disease.
Symptoms to watch out for
Heart disease symptoms can vary significantly depending on the type, and in some cases, even advanced disease may not present with any noticeable symptoms. However, some common symptoms include:
- Chest pain, tightness, or pressure
- Shortness of breath
- Pain in the arms, neck, jaw, upper belly or back
- Fatigue
- Dizziness
- Pain, coldness, or swelling in the feet, ankles, or leg
- Palpitations or fluttering, skipped beats
- Nausea, vomiting, loss of appetite
Recent studies have also shown that depression and anxiety are commonly seen in multiple types of heart disease. There can also be differences in how men and women perceive certain symptoms.
Oftentimes, people with risk factors for heart disease or even those with early stages of heart disease may not experience any symptoms. For this reason, it’s important to stay on top of your health and schedule routine visits with your healthcare providers. Knowing what numbers to look out for in your lab tests can help you and your healthcare team recognize heart disease and stop its progression in its tracks.
Know your numbers
People with diabetes are all too familiar with A1C levels, as they are still used as the gold standard for determining one’s average blood glucose levels over the past two to three months. An A1C of 6.5% or higher is the criteria used to diagnose diabetes, and most experts recommend that people with diabetes aim for an A1C of less than 7%.
Another metric that can be viewed on a continuous glucose monitor (CGM) is time in range, which is the percentage of time a person spends with their blood glucose in a target range. Time in range is recognized by the American Diabetes Association (ADA) as a valid tool for assessing blood sugar levels, and it is recommended that people with type 1 and type 2 diabetes aim to spend at least 70% of their day (or 17 out of 24 hours) with blood sugars between 70 and 180 mg/dL.
Triglycerides and cholesterol are measured with a fasting blood test. It is important to have this done each year, or as recommended by your healthcare professional. While HDL cholesterol or "good" cholesterol is associated with a lower risk of heart disease by helping to remove cholesterol from the arteries, it is no longer a target for treatment. On the other hand, LDL cholesterol and non-HDL cholesterol (types of "bad" cholesterol) can contribute to plaque buildup and lead to atherosclerosis, increasing the risk of heart disease. The American Heart Association notes the following healthy ranges:
- Total cholesterol: Less than 150 mg/dL
- LDL cholesterol: Less than 100 mg/dL
- Non-HDL cholesterol: Less than 130 mg/dL
- Triglycerides: Less than 150 mg/dL
The LDL cholesterol targets for people with diabetes vary. For people with diabetes who are otherwise healthy, the target LDL cholesterol is less than 100 mg/dL (2.6 mmol/L). For people with diabetes aged 40–75 years at higher cardiovascular risk, including those with one or more additional cardiovascular risk factors, treatment is recommended to obtain a goal of less than 70 mg/dL (1.8 mmol/L). For people with diabetes and heart disease, treatment is recommended to obtain an LDL cholesterol goal of less than 55 mg/dL (1.4 mmol/L).
Treating high blood pressure (defined as equal to or over 130/80 mmHg) has been shown by countless studies to reduce the risk of heart disease and cardiovascular events. Keeping it below 120/80 is even better for supporting the health of your kidneys. Although your healthcare provider should be checking your blood pressure at each visit, it can also be measured at home with an arm cuff. Ask your doctor how often you should measure your blood pressure.
Excess weight can also be a risk factor for developing heart disease. Because abdominal fat specifically is strongly associated with heart disease, waist circumference is often used as an indicator of body composition, and adds valuable information along with body mass index (BMI). While these measures do not tell the whole story, they are widely used diagnostic tools and are most helpful when combined with other measurements (as described in this article). The following are healthy ranges for BMI and waist circumference:
- BMI: 18.5-24.9
- Waist circumference: Less than 35 inches for women and less than 40 inches for men. Measured at belly button level against bare skin.
Your heart and kidneys work hand-in-hand to keep blood circulating and to balance fluids in your body. The heart pumps blood to the kidneys, allowing them to filter waste and excess fluids from the bloodstream. In return, the kidneys help regulate blood pressure by controlling the amount of water and salt in the body, making sure the heart has the optimal conditions to pump blood efficiently.
When one system fails, the other has to work harder to keep the body balanced. People with reduced kidney function or chronic kidney disease (CKD) are at increased risk of heart disease. There are many tests that measure kidney function, but here are two that are highlighted by the National Kidney Foundation and should be measured at least annually:
- Estimated glomerular filtration rate (eGFR) is a blood test that tells you how well the kidneys are filtering blood:
- An eGFR of >90 is considered normal in most healthy individuals
- An eGFR of 60-89 may be considered normal, but could also indicate early-stage kidney disease
- An eGFR of 15-59 indicates that there is damage to the kidneys
- An eGFR below 15 is usually an indicator of kidney failure
- Urine albumin-to-creatinine ratio (UACR) is a urine test that measures how much albumin and creatinine are present. While creatinine is expected to be found in the urine, the presence of albumin can indicate that the kidneys are damaged.
- UACR of less than 30 is considered normal
- UACR or 30 to 299 is considered “moderately increased”.
- UACR of 300 or higher is considered “severely increased,” and may mean you have a significantly higher risk for kidney failure or having a heart attack or stroke.
Improve your numbers
There are several ways to use these numbers to your advantage and improve your heart health, whether or not you already have heart disease.
It’s important to note that the ADA’s 2025 Standards of Care highlights the fact that most evidence supporting interventions to reduce heart disease risk in diabetes comes from studies of people with type 2 diabetes. Since clinical trials haven’t been specifically designed to assess the impact of these risk reduction strategies in people with type 1 diabetes, the recommendations are similar to those for people with type 2 diabetes.
Reaching blood glucose targets, treating high blood pressure, and managing cholesterol levels is crucial for preventing serious complications like heart failure. GLP-1s (like Ozempic) and SGLT-2 inhibitors (like Jardiance) can help with blood sugar management, and statins (like Lipitor) can improve cholesterol levels. It’s important to discuss these medications with your healthcare provider to reduce your odds of developing heart disease.
Lifestyle modifications are also key to reducing the risks associated with heart disease, and getting more physical activity can make a major difference. In fact, a new study found that watching TV for more than two hours per day was linked to a higher chance of developing heart disease. Even among people with a genetic predisposition for type 2 diabetes, those who watched an hour or less of TV per day had a significantly lower risk of developing heart disease in the next 10 years.
Staying active and aiming for 150 minutes of exercise per week, eating a balanced diet rich in fiber, and quitting smoking and/or vaping are fundamental steps you can take to take care of your heart with diabetes.
The bottom line
By monitoring key health metrics, making lifestyle changes, and working closely with healthcare providers, people with diabetes can significantly reduce their risk of heart disease and its complications. Early intervention and proactive care can make a meaningful difference in protecting your heart health.
Learn more about heart disease and diabetes here: