A new study published this week in the Journal of the American Heart Association shows more than half of American Indian teens and young adults have high cholesterol.

Part of the research was based on tribal communities in Arizona.

Researchers looked at data for nearly 1,500 teens and adults enrolled in the Strong Heart Family Study. It examined risk factors for heart disease and stroke in tribal communities in central Arizona, southwest Oklahoma and the Dakotas.

Among American Indians from 15 to 19 years old, 55% had high cholesterol. About 74% in their 20s had it, and so did 78% of those in their 30s.

The study also found that very few of them were being treated.

Heart disease rates among American Indians and Alaska Natives are much higher than their white peers. They also develop cardiovascular diseases at younger ages.