There are several nasty conditions that diabetes can lead to, including heart disease. How will you know if you're at risk for this? An often overlooked blood test may be just the key to helping diabetics improve their health.

Two separate studies suggest that people with both type 1 and type 2 diabetes should regularly take the hemoglobin A1c test, on top of their regular checks of blood sugar. The HA1c test looks for glycated hemoglobin, also called glycosylated hemoglobin, and is a measure of how well blood sugar is controlled.

Writing in the Annals of Internal Medicine, they said a 1 percentage point increase in HA1c predicted an 18 percent increase in risk for total cardiovascular disease and a 28 percent risk for peripheral vascular disease -- clogged arteries in the legs, for instance.