Know your Big 3 heart numbers

Many tests and numbers can help you manage your overall health. But when it comes to heart health, you need to focus on the Big 3: blood pressure, cholesterol, and blood sugar.

"These best predict cardiovascular disease risks, including heart disease, heart attack, and stroke," says Dr. Howard LeWine, editor in chief of Harvard Men's Health Watch.

While there are standard guidelines for what is considered healthy for the Big 3, your ideal numbers may differ depending on your health and other risk factors. "Your doctor can direct you about which numbers and ranges you should aim for and the best ways to achieve them," says Dr. LeWine.

Here's a look at the Big 3, why they matter, and how to measure them.

1: Blood pressure

A blood pressure reading has two components: systolic pressure and diastolic pressure. Systolic pressure (the top number) represents the pressure in the blood vessels when the heart contracts to pump blood. Diastolic pressure (the bottom number) refers to the pressure in the vessels between heartbeats.

While both numbers are essential for diagnosing and treating high blood pressure, doctors primarily focus on systolic pressure. "Most studies show a greater risk of stroke and heart disease related to higher systolic pressures rather than elevated diastolic pressures," says Dr. LeWine. "That's especially true in people 50 and older." Blood pressure is measured in millimeters of mercury (mm Hg). Readings are categorized as follows:

• normal blood pressure: less than 120/80 mm Hg
• elevated blood pressure: 120/80 to 129/89 mm Hg
• Stage 1 hypertension: 130/80 to 139/89 mm Hg
• Stage 2 hypertension: 140/90 mm Hg and higher.

If either component of your blood pressure is above the normal range, your initial action should be lifestyle changes. This includes losing weight, if necessary; increasing daily physical activity; eating more fruits and vegetables; and limiting salt intake. "Many people don't need to have perfect blood pressure," says Dr. LeWine. "You and your doctor can decide on your personal goal numbers, which may be higher than the magical 120/80 mm Hg, or possibly lower if you have heart disease or other cardiovascular issues."

He adds that a home blood pressure monitor is the best way to regularly check your blood pressure. Look for a model with an upper arm cuff that automatically inflates. (Devices with a wrist cuff or fingertip sensors are less accurate.) Make sure the cuff is the proper size, as too-small cuffs can give a false reading. Dr. LeWine suggests taking measurements twice daily — morning and evening — for several days to get a baseline reading. (Blood pressure should be lowest when you first wake up and typically rises in the late afternoon and evening.) After that, take readings daily or every other day for the next couple of weeks. In the long term, check your blood pressure two to three times a week or when you think it might be high (for example, if you feel stressed) or low (because you feel fatigued).

"You should alert your doctor to any changes outside your personal goal range that last longer than a few days," says Dr. LeWine.

2. Cholesterol

Cholesterol is a fatty substance that occurs naturally in the body. Different forms of cholesterol and other fats (lipids) circulate in the blood. A traditional blood lipid panel measures low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, total cholesterol (both LDL and HDL), and triglycerides.

"Doctors primarily focus on "bad" LDL cholesterol levels because of their close connection with the amount of fatty plaque buildup inside arteries, raising the risk of heart attack and stroke," says Dr. LeWine.

Your goal level for LDL depends on your risk factor profile. In general, the lower the number, the better. If you already have cardiovascular disease or are at high risk for it, you should aim for an LDL of less than 70 milligrams per deciliter (mg/dL).

Achieving less than 100 mg/dL with lifestyle changes is reasonable for people at average risk. You and your doctor can decide if you need to take a statin drug to lower your LDL. However, if you do not have cardiovascular disease and have no risk factors for it, an LDL level of 100 to 130 mg/dL may be acceptable. Levels higher than 130 mg/dL usually require drug therapy when lifestyle changes aren't enough.

A blood lipid panel also reveals your triglyceride level. Triglycerides are a type of fat in the blood that the body uses for energy. The combination of high levels of triglycerides with low HDL or high LDL also can increase your risk for heart attack and stroke.

In general, a triglyceride level of less than 150 mg/dL is a good goal. With levels between 150 and 500 mg/dL, the usual strategy to lower levels is by moderating alcohol intake, losing weight, and cutting back on carbs. If you have elevated levels of LDL and triglycerides, a statin can lower both. Other drugs are available that target high triglycerides.

3. Blood sugar

Keeping track of your average blood sugar levels, even if you don't have diabetes, also can help assess your heart health. A blood test for hemoglobin A1c measures your average blood sugar (glucose) levels over the past three months. The test can be done anytime during the day and does not require fasting.

The results can determine if you have prediabetes or undiagnosed type 2 diabetes, either of which greatly increases your risk of cardiovascular disease. "If you fall into one of these categories, you will likely want lower goals for both blood pressure and LDL cholesterol," says Dr. LeWine.

A normal A1c reading is below 5.7%. A reading of 5.7% to 6.4% indicates prediabetes, and a reading of 6.5% or higher is classified as having diabetes. If your results are normal and your weight remains stable, you probably won't need another test for two to three years.

If you have prediabetes, your doctor will recommend that you try more intensive lifestyle changes and have another test in six months to a year. "Many older adults with prediabetes don't progress to full diabetes if they maintain a healthy weight, exercise regularly, and eat a healthy diet," says Dr. LeWine. "But prediabetes indicates a need to pay even more attention to all other cardiovascular risk factors."

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