Diabetes Complications Killed Casey Johnson

Coroner releases statement saying heiress died of natural causes due to low insulin level

Casey Johnson struggled all her life with diabetes, and in the end, the disease claimed her life.

The Los Angeles County coroner just announced that the 30-year-old Johnson & Johnson heiress's death was caused by diabetic ketoacidosis, a condition triggered by low levels of insulin in a diabetic's system.

Her death was deemed natural—not due to drugs or even suicide, as some speculated. And it was something Johnson "always feared would kill her," says a former girlfriend.

"Casey battled juvenile diabetes her entire life," Courtenay Semel told E! News. "I hope that at least this will bring awareness to the fight against diabetes and maybe one day we can all win her battle for her and find a cure," she said.

Just weeks ago, Semel revealed to E! News that Johnson's inability to manage her diabetes led to frequent trips to the emergency room.

The results are vindicating, former Johnson fiancée Tila Tequila exclusively told E! News. "I always knew that and that’s why I would get so upset when I hear bloggers and reporters talk about her past heavy drug abuse problems, insinuating that might have been a reason she died," said Tequila.

Officials say a detailed report on her death will be released within the next two weeks.

Johnson, 30, was found dead in her rental home in L.A. Jan. 4; she was laid to rest in her native New Jersey eight days later.