April 17 (Bloomberg) — Improved preventative care for diabetes has cut the rate of serious complications such as heart attack and stroke over the past 20 years while the number of Americans diagnosed with the disease continues to rise, a government report found.

Diagnosed diabetes cases tripled to 20.7 million in 2010 from 6.5 million in 1990, according to research from the Centers for Disease Control and Prevention published yesterday in the New England Journal of Medicine. The jump in diagnoses resulted in more people suffering from complications despite the rate reduction, said Linda Geiss, one of the study authors.

"Although we've seen a decline in the rates and we've come a long way in preventing the complications and improving the quality of life for people with diabetes, most of the numbers are still increasing," Geiss, head of diabetes surveillance at the CDC in Atlanta, said in a telephone interview. "We need to make some progress in preventing Type 2 diabetes in order to help decrease these numbers."