The Los Angeles Coroner's office announced on Thursday that socialite Casey Johnson's death last month was a result of lethal complications of her diabetes.   According to The Associated Press, Johnson, 30, an heir to the Johnson & Johnson health-care products fortune, died of diabetic ketoacidosis, a life-threatening condition caused by lack of insulin, leading to poisonous levels of acids called ketones in the blood. That combination is deadly for someone like Johnson, who had been an insulin-dependant diabetic since childhood.

Johnson was found dead on January 4 in her home, and an initial autopsy could not determine the cause of her death. The openly bisexual heiress, who was reportedly engaged to reality star Tila Tequila at the time of her death, was known to have struggled with substance abuse, but the brief coroner's statement cited natural causes and did not mention any other contributing factors to her death.

TMZ, citing unnamed sources with access to the coroner's report, said that the death finding concluded that Johnson had not been taking her insulin regularly and was not exercising, following her strict diet or taking the necessary medications to manage her diabetes.

Diabetic ketoacidosis can often lead to a diabetic coma due to the lack of insulin in the body, and Johnson had reportedly slipped into comas at least twice before her death.