Albumin-to-creatinine ratio. This biomarker describes the ratio, or balance, between two substances, creatinine and albumin, that are both waste products normally found in urine. Test results are reported as milligrams (mg) of albumin per gram (g) of creatinine. Studies have suggested that this ratio is an independent risk factor for cardiovascular disease, especially in people with diabetes or hypertension (high blood pressure). It is more commonly used, however, to screen for kidney disease, as increased albumin in the urine is often an early sign of reduced kidney function.
Plasminogen activator inhibitor-1. This biomarker, a protein, is associated with thrombosis, or clotting of the blood. It can increase when you have an infection, certain kinds of inflammation, or an injury. Low levels of it may make a person susceptible to bleeding disorders. In people with diabetes, particularly those who are obese, plasminogen activator inhibitor-1 levels are commonly elevated, which is associated with a higher risk of cardiovascular disease. It is believed that this protein plays a role in the development of atherosclerosis (“hardening of the arteries”), in which fatty deposits build up in the arteries and restrict blood flow.
Adiponectin. This hormone helps control blood glucose levels and the breakdown of fats in the body. Although scientists are not exactly sure why, reduced levels of adinopenectin are associated with various “classic” risk factors for cardiovascular disease such as Type 2 diabetes, obesity, and atherosclerosis.
It is important to note that only a few cardiovascular biomarker tests are routinely used at present, and not by all health-care providers. However, since these tests may yield evidence of cardiovascular risk before classic risk factors are present, they may be useful for people with diabetes, due to their already elevated risk of cardiovascular disease. Your health-care provider will likely decide whether or not to test certain biomarkers based on your risk for cardiovascular disease as determined by classic risk factors, as well as based on his experience with the usefulness of testing.
Interpreting your results
When you have any type of laboratory test performed, it is important that you understand what the results mean for you. When your lab tests are reported to your health-care provider, he will usually compare the result with a reference range that is supplied as part of the laboratory analysis (see “Cardiovascular Biomarker Tests”). The term “reference” is preferred to “normal” because normal is often difficult to define. A reference range is based on the numbers typically seen within a group of healthy individuals. If appropriate for a particular lab test, the reference range will take your age and sex into consideration.
Your health-care provider will evaluate your results within the full context of your medical status. In doing so, he may take several things into account, depending on the specific test. These additional considerations may include any medicines, vitamins, or herbal remedies you’re taking; your caffeine intake; any tobacco or alcohol use; your dietary preferences (such as whether you are a vegetarian); and your stress or anxiety level. Exercise and physical activity can also alter some enzyme and hormone levels. Pregnancy can affect a woman’s laboratory values; for many tests, in fact, there is a separate reference range for pregnant women. Because your test results may be affected by various lifestyle choices or personal characteristics, it is important that you accurately and completely answer any questions your health-care provider has about behaviors that may affect how test results are interpreted.