Know your numbers for heart health

Information about health is often accompanied by numbers  how many people have this disease, what’s the risk of developing that condition.  Then there are more personal numbers, such as your targets for your blood sugar and the right body weight that’s healthy for you.  Understanding all these numbers can be confusing, and much of what this article today aims to do is to help you make sense of the numbers that you need to maintain to keep a healthy heart.

Your heart is your body’s fuel pump, responsible for circulating blood through the carburetor of the lungs, out into the rest of the human machine, and back again.  This dynamic sack of muscle, about the size of a fist, beats an average of 70 times a minute  38 million times a year.  It moves blood through a system of arteries, veins, and capillaries that would reach 60,000 miles long if stretched end to end.

Heart disease is the no. 1 killer in the Philippines today.  Here are some sobering statistics on conditions that can affect your heart:  Department of Health data show that 25 percent of Filipino adults, or about 14 million of the current adult population, have high blood pressure.  A 2011 survey done by the Food and Nutrition Research Institute showed that 22.3 percent Filipino adults are overweight and six percent are obese.  More than 10 years ago, it was estimated that only four percent of adult Filipinos were diabetic, now the estimate is about 20.6 percent.

Here are the numbers that matter the most for your heart.

Blood pressure

Blood pressure measures the force of circulating blood that’s pressing against your artery walls.  The harder your heart pumps out and the less flexible your artery wall becomes, the higher your blood pressure.

High blood pressure (hypertension) damages and scars the arteries.  It’s one of the major risk factors for heart disease.  If not treated, high blood pressure can cause a heart attack, stroke or heart failure.

At least one-third of adults with high blood pressure probably don’t even realize they have it.  Most people show no signs or symptoms. The only way to know if you have high blood pressure is to be tested.  Starting at age 18, have your blood pressure checked every two years.  You may be screened earlier if you have additional risk factors. If you already have high blood pressure, your blood pressure will be checked more often.

• The test.  Blood pressure is generally measured with an inflatable arm cuff and a pressure-measuring gauge.  A blood pressure reading, given in millimeters of mercury (mm Hg), has two numbers  sometimes stacked one on top of the other like a fraction:  The top number measures the pressure in your arteries when your heart beats (systolic pressure).  The bottom number measures the pressure in your arteries between heart beats (diastolic pressure).

• Blood pressure categories.  Normal blood pressure is a systolic under 120 and a diastolic under 80.  A systolic of 120-139 or diastolic of 80-89 is prehypertension.  Hypertension means a systolic of 140 and over or diastolic of 90 and over. 

For example, if your systolic pressure is 115mm Hg and your diastolic pressure is 78mm Hg, your blood pressure is written as 115/78 and spoken as 115 over 78  putting you in the normal blood pressure category (under 120/80).  If the two numbers fall into different categories, the higher category is where you’re placed.  So, if your test results are 125/78, you may be placed in the prehypertensive category.

After age 50, the systolic number becomes more significant.  Isolated systolic hypertension (ISH) when the bottom number is normal but the top is high  is the most common type of high blood pressure among older adults, especially women.  Prehypertension often leads to hypertension and puts you at risk of developing heart and blood vessel disease.    Extremely high blood pressure  readings of 180/110 and over  can be life-threatening and requires emergency medical attention.

A doctor generally takes readings at two or more visits before giving a diagnosis of high blood pressure.  That’s because blood pressure varies from day to day.  It can vary with exercise, sleep, stress, and even posture changes.

Cholesterol

Your body needs cholesterol  a waxy substance found in the fats (lipids) carried in your  bloodstream  to build healthy cells. But too much cholesterol causes fatty deposits to build up in your blood vessels.  This can lead to narrowed or blocked arteries (atherosclerosis), a major cause of heart disease.   Most people with high cholesterol feel fine and don’t experience signs or symptoms.  Being tested and knowing the test results is the best way to keep cholesterol levels within healthy limits.

• The test.  A complete cholesterol test, called a lipid panel or a lipid profile, measures how much cholesterol and triglycerides you carry in your bloodstream.  (We’ll get to triglycerides later.)  The simple blood test determines:

• Low-density lipoprotein (LDL) cholesterol.   This is sometimes called “bad” cholesterol. Too much of it in your blood causes atherosclerosis.  The deposits can rupture, leading to heart attack or stroke.

• High-density lipoprotein (HDL) cholesterol.  This is sometimes called “good” cholesterol because it helps carry away excess LDL cholesterol in your blood.

• Total cholesterol.  This is the sum of your blood’s cholesterol content.

You may be given a number for non-HDL cholesterol  which accounts for all forms of cholesterol minus your HDL cholesterol (there’s more than just LDL and HDL cholesterol). This number may be a better indicator of heart risk than your LDL alone.

All adults age 20 or older should have a full lipid profile taken once every five years. If you already have high cholesterol levels or a family history of early coronary artery disease, your doctor may ask for more frequent testing.  New guidelines recommend checking cholesterol in all children ages nine to eleven, and earlier in families with a strong history of heart disease.

Cholesterol is measured in milligrams of cholesterol per deciliter (mg/dL) of blood.  The numbers categorize your risk level for heart disease. These categories may not be in step with the cholesterol goals recommended by your doctor.  For example, if you have heart disease, your doctor may ask that you aim for LDL cholesterol below 70 mg/dL.

Triglycerides

Triglycerides are another type of fat in your bloodstream.  When you eat, your body converts calories it doesn’t need into triglycerides.  High triglyceride levels are common in people who are overweight or have diabetes, don’t exercise regularly, eat too many sweets and carbohydrates, or drink too much alcohol.  Triglyceride levels above 200 are linked to an increased risk of death from cardiovascular disease.

• The test.  Triglycerides are measured in milligrams per deciliter of blood (mg/dL), and are normally included in a full cholesterol test.  Triglycerides levels are generally higher during pregnancy, as shown in the accompanying table (refer to chart on triglycerides).

Body mass index

You may know that being overweight increases your risk of heart disease.  But how do you know if you’re overweight? Weight is typically measured by a number known as your body mass index (BMI), which measures your weight in relation to your height.

• The numbers.  Here’s how BMI numbers are split into different weight categories: Normal Weight: 18.5 to 24.9; Overweight: 25.0 to 29.9; Obese: 30.00 to 39.2, and Extreme Obesity:  40.00 and above (refer to BMI table on Page D-1).

BMI isn’t a perfect measure of healthy weight.  Critics say it underestimates obesity, particularly among white and Hispanic women. It can also mistakenly label athletes with lots of lean muscle mass as obese.  Talk to your doctor about your BMI number and whether you need to improve it. 

Your doctor can also help you calculate your BMI and discuss ways that you can control or lose weight with diet and exercise.  A free BMI calculator is also available from the US National Heart, Lung, and Blood Institute at www.nhlbisupport.com/bmi.

• Measure your middle.  Another important weight-related number to know is your waist measurement.  Fat around your middle is an independent risk factor for heart disease.  If you have a large waistline, your risk of heart disease is high, even if your BMI is normal.  Compared with fat in your legs or buttocks, belly fat has more dangerous health consequences.

A waist measurement of more than 35 inches (89 cm.) for women or more than 40 inches (102 cm.) for men is considered high risk.  You can’t just “spot reduce” your belly fat, so work on overall weight loss.  As you lose weight, your waistline will shrink.

Blood sugar

Blood sugar (glucose) is your body’s main fuel source.  If dangerous levels of blood sugar build up in your bloodstream, you can develop diabetes.  Because the signs and symptoms come on gradually, you might have high blood sugar without even knowing it.  If you have diabetes, controlling your blood sugar level helps you feel your best and prevents further complications, including heart disease.

• The test.   The main test for diagnosing diabetes is a fasting plasma glucose test.  It involves analyzing the level of blood sugar in a small sample of your blood after an overnight fast.  It is recommended that all adults 45 and older be tested every three years.  People with risk factors for diabetes should be tested earlier and more often.

If your test results are above normal, your doctor will repeat the test on a different day.  If your blood falls consistently in the range of 100 to 125 mg/dL, you’re considered to be at high risk of developing diabetes.  This condition is sometimes called prediabetes and is linked to a high risk of heart disease.  A blood sugar level that is consistently at 126 mg/dL or higher generally means you’ll be diagnosed with diabetes.  The disease can damage major arteries as well as small blood vessels, increasing your risk of heart attack, stroke, and other disorders from impaired circulation.

If you have diabetes, the glycated hemoglobin, or HBA1c, test can indicate how well you’ve been managing your blood sugar over the previous two to three months.  You’re doing well if the test shows that your average HBA1c level has been at 5.7 percent or lower.

What’s in a number?

So, what’s in a number? When it comes to your health, the answer is plenty.  That’s because knowing and understanding certain numbers can keep you from being caught off guard by many serious illnesses, and help you maintain or improve your health.  Use them to help you get to and stay on the path of good health.