Bottom line: The more controlled, the better. The normal range for a fasting blood glucose test is typically less than 100 milligrams per deciliter; prediabetes is indicated by a level between 100 and 125 mg/dL and diabetes by a reading of 126 mg/dL or above. A normal hemoglobin A1C level is below 6 percent, and those with diabetes should aim to keep it under 7 percent.
C-reactive protein. Inflammation is a process our body uses to fight off an assault, like a cold or injury, in order to heal. But over the long term, chronic inflammation plays a detrimental role to health because the nasty byproducts—inflammatory molecules like cytokines—are believed to be part of several disease processes, including atherosclerosis, obesity, and Alzheimer's disease. In the realm of heart disease, much ado has been made of c-reactive protein, a marker for one's level of inflammation that can be picked up through a blood test called hs-CRP, for high-sensitivity c-reactive protein.
Who should get the test, and what are doctors to do with the results? Those are matters of considerable debate. "We can't treat high [c-reactive protein]," says Whiteson. It's an indicator of potential heart trouble, but medicine doesn't have the tools, via mediations or procedures, to bring an elevated c-reactive protein down to normal. It is possible, however, to directly treat other critical risk factors like high blood pressure and high cholesterol. Doing so can bring down the risk of future cardiac events and death. A landmark study from late 2008 found that subjects who did not have heart disease and had normal cholesterol and who took statins had a lower risk of heart attack and stroke and also had fewer angioplasties and bypass surgeries over the course of the study, compared with the group who took a placebo. But too many questions remain about the study to make a blanket statement that folks should be taking statins more liberally.
Bottom line: According to the AHA, an hs-CRP measure of 1 mg/L means you are at low risk of developing cardiovascular disease, a measure between 1 and 3 mg/L means you are at average risk, and levels above 3 mg/L means your risk is high. Getting the test may be helpful, says Yancy, if you are at intermediate risk for heart disease based on other risk factors and your doctors would like another data point to determine treatment. But "there is no need to check CRP if a person already has high risk or truly is in the healthy bracket," he says.
Waist circumference. While not a direct measure of heart disease, a high waist circumference tracks with increased risk for high blood pressure, high cholesterol, and diabetes—all of which have a direct impact on heart health. And the bigger the belly, the heavier one tends to be. Obesity, of course, is a well-known risk factor for a range of diseases, including heart disease.
Importantly, a higher waist circumference indicates distribution of fat around the abdomen and packing fat around vital organs, which research has indicated is more dangerous than carrying weight in the thighs or buttocks. Be sure you're measuring properly. The correct waist circumference measurement is taken by wrapping a measuring tape around the natural waist at the belly button, not around the hips.
Bottom line: Men should have a waist circumference of less than 40 inches. The figure for women is less than 35 inches.
Body mass index. Your weight matters, but it has to be considered in the context of how tall you are. Body mass index takes the two numbers into account. Like waist circumference, BMI is an indirect measure of risk, but a higher measure correlates with greater risk. The catch, however, is that it is not always entirely accurate. A person in excellent condition who has a lot of muscle mass may have a high BMI.