Health Update

by Tyrone M. Reyes, M.D.

You don’t have to be a doctor to ferret out the clues to your cardiovascular well-being in lab tests of your blood. Growing numbers of people are doing it. More and more patients want to have complete copies of their lab results. hey want to see the raw data, and if a number is out of the normal range, they circle it and want to know why. That’s good and not-so-good news.

• Good news: Taking an interest in your numbers means you’re more likely to excel in self-care. With further input from your physician, the numbers can suggest new treatments or preventive steps. Sometimes, patients spot trends in lab findings that their doctors miss.

• Not-so-good news: Some people worry too much because they put excessive credence in one result that’s slightly out of the normal range.

Some Results Are Flatly Wrong

On average, “If you order 20 lab tests for the same person, one of them will come back abnormal,” says cardiologist Richard Krasuski, MD, of Cleveland Clinic. “That’s because of normal variation or lab errors, not because you have something to worry about. And most lab data require some interpretation from your doctor based on such factors as your age, gender or body composition.

Take for example, creatinine, a muscle breakdown product. It’s cleared out of the kidneys. So, a creatinine buildup in the blood can be a sign that your kidneys aren’t working well. And kidney dysfunction is one of the strongest risk factors for cardiovascular disease. But judging the risk strictly on the basis of raw numbers could be wrong. For example, a small older woman with a creatinine of 1.3 mg/dL may be at greater risk than a hefty man with a level of 1.4 mg/dL because of the woman’s slight build and gender even though her lab reading is lower. What does it mean to you? Rely on your doctor to put your lab results in context so you can get a more accurate picture of your health.

Learning what a few tests in your lab works mean is a good way to reduce blood-test anxiety and take greater control over your heart’s health. Here’s a simple guide to seven important blood test results.

Look For Clues In Your Report

• Total cholesterol is the number you’re most likely to remember. Celebrate when it’s down (lower than 200 mg/dL) or lament when it’s up (higher than 200 mg/dL). It’s useful as a shorthand overview of cholesterol, the fat-like substance in foods such as meat, eggs, poultry, and dairy products. At high levels, cholesterol can raise the threat of a heart attack. But your physician is more likely to pay attention to other more revealing numbers (particularly LDL) that contribute to total cholesterol. Here’s why.

• LDL cholesterol short for low density lipoprotein, looms larger than most numbers on your lab report because its ups and downs are linked with profound changes in your cardiovascular risks.

LDL particles are bundles of cholesterol wrapped in a thin layer of protein. The particles travel through the blood to unload the cholesterol where it’s needed, for example, to repair cells. But when levels are high, cholesterol unloads into the walls of your arteries, notching up your heart attack threat level. Research in recent years indicates that LDLs below 100 mg/dL are optimal for people at a very high risk of heart disease. If your doctor tells you you’re at a very high risk, the latest research-based recommendations suggest that aiming for LDL levels below 70 is a reasonable strategy.

An elevated LDL number doesn’t necessarily mean you’ll need statins, proven medications that inhibit the production of cholesterol in your liver. Increasing fiber in your diet, by eating more fruits, vegetables, and whole grains like oatmeal can help pull your “bad” cholesterol down to a healthy range. So can cutting back on saturated fat and cholesterol. Another option is an old-standby vitamin pill, niacin (vitamin B3). In doses of 1,000 mg or more daily, it can lower LDL by up to 25 percent and also raise your HDL (“good cholesterol”). But in a small percentage of users, it can cause facial flushing (uncomfortable but not dangerous) and liver problems (potentially serious and requiring periodic monitoring). Other LDL-taming medications to discuss with your doctor include bile acid sequestrants and fibric acids.

• HDL cholesterol — high density lipoprotein — is the “good” counterpart to the “bad” LDL because it transports excess blood cholesterol back to the liver where it’s processed out of the body. So higher HDL is better. Greater than or equal to 60 mg/dL is considered high. Lower than 40 mg/dL signals potential problems. Niacin can raise “good” cholesterol levels 15 percent or more.

• Triglycerides — the most common fat in the body and blood — is generally considered normal at levels less than 150 mg/dL. Higher levels are linked with greater heart risks, but “we have no conclusive proof that treatment of triglycerides reduced cardiovascular risks,” Dr. Krasuski says.

If your triglyceride level is high, your doctor will probably suggest the same steps you would take to lower LDL. New research suggests that exercise may be significantly helpful in reining in triglycerides.

• Creatinine is a waste product in blood that, like household trash, usually gets removed at a relatively steady rate. In the circulatory system, the waste-disposal workers are the kidneys. If they’re operating well, they consistently hold down creatinine levels below about 1.3 mg/dL.

• Potassium. Levels of this common salt in your blood give cardiologists important information about whether you can take some blood pressure medications commonly prescribed to people with cardiac risk factors. Normal potassium levels range between about 3.5 and 5 mmol/L. ACE inhibitors or angiotensin receptor blockers can raise potassium levels.

Diuretics, another antihypertensive drug, can lower potassium. Too high or low potassium can cause potentially serious heart rhythm irregularities.

• Glucose, blood sugar. Goals have dropped in recent years. Today’s standard: Levels below 100 mg/dL are normal. If your numbers after fasting are over 126 mg/dL, you have diabetes. Between 100 and 125, you’re at elevated risk (pre-diabetes).

The progression from pre- to full-fledged diabetes — another cardiovascular risk factor — isn’t inevitable. Most important defensive moves: Lose weight, exercise more.

What You Can Do

And finally, here’s what you can do about your lab results:

• Today, retrieve past lab results, arrange them chronologically, and compare your latest results with previous findings.

• If a single recent number differs greatly from earlier levels, ask your doctor if further testing is appropriate.

• If your triglyceride level ever goes above 400 mg/dL, request a direct test of your LDL (“bad”) cholesterol.

• From now on, ask your doctor to interpret lab results in the light of your age, body composition, gender, and race.

Yes, a closer look at these lab tests can reveal new ways to protect your cardiac health.

Source: Philippine Star