LOS ANGELES - Officials say actress Carrie Fisher died from sleep apnea and a combination of other factors, but they could not conclusively determine what caused her death.

Los Angeles coroner's officials said in a news release late Friday that Fisher had buildup of fat in the walls of her arteries. The release states that Fisher had taken multiple drugs prior to her death, but that investigators could not determined whether they contributed to her death in December.

The agency did not immediately respond to a request for additional details about whether a full autopsy report and toxicology results were available.

Fisher suffered a medical emergency on an international flight on Dec. 23. Her mother, longtime movie star Debbie Reynolds, died the following day.