1 in 8 US adults have this deadly disease, and even more are dangerously close to developing it

New research suggests that half of all U.S. adults have diabetes or pre-diabetes, conditions that can lead to other complications later in life.

The study of government health surveys echoes previous research and shows numbers increased substantially between 1988 and 2012 although they mostly leveled off after 2008.

Overall, 12-14% of adults had diagnosed diabetes in 2012, the latest data available. Most of that is Type 2 diabetes, the kind linked with obesity and inactivity.

Almost 40% have pre-diabetes, meaning elevated blood sugar levels that could lead to full-fledged disease. Studies have shown lifestyle changes can delay or prevent diabetes in these people.

That 40% is more than the Centers for Disease Control accounted for in 2014, when they estimated that 1 in 3 adults in the US has pre-diabetes.

Diabetes is a disease that causes the body to either resist the effects of insulin - the main hormone responsible for breaking down the sugar we eat into blood sugar - or to not produce enough of that hormone to keep our blood sugar steady.

Currently, 29 million people in the US have diabetes. That number could increase if the almost 40% of people living with pre-diabetes don't change their habits.

The study is based on surveys involving in-home exams and questionnaires. It was published in Tuesday's Journal of the American Medical Association.