ST. PAUL — Health officials said the diabetes rate has doubled in Minnesota in the past 20 years and that there are tens of thousands of people who have the disease, but don’t know it.

The Minnesota Department of Health estimates about 290,000 Minnesotans have been diagnosed with diabetes, and that 80,000 others have it, but aren’t aware of it because symptoms of type 2 diabetes aren’t that obvious. The health department estimates more than a million Minnesotans have pre-diabetes but don’t know it.

Health officials attribute the rising diabetes rate to obesity and an aging population.