Michelle Trachtenberg’s official cause of death revealed as complications of diabetes

Michelle Trachtenberg‘s official cause of death at 39 has been revealed.

The Buffy the Vampire Slayer and Gossip Girl actress died as a result of complications of diabetes mellitus, the New York City Office of Chief Medical Examiner said Wednesday in a statement to Entertainment Weekly. The finding came after review of laboratory test results, and the manner of death was ruled as natural.

The news comes seven weeks after the OCME confirmed that Trachtenberg’s had family objected to an autopsy being performed, and therefore the cause and manner of her death were considered “undetermined.”

Trachtenberg was found unconscious and unresponsive in her New York apartment on the morning of Feb. 26, and emergency services pronounced her dead at the scene. Police indicated at the time that “criminality [was] not suspected,” and sources told PEOPLE that the actress had received a liver transplant in the months before her death.

Trachtenberg’s passing prompted an outpouring of grief from fans and former castmates.

Rosie O’Donnell, who costarred with Trachtenberg in her breakout movie, Harriet the Spy, said in a heartfelt statement, “I loved her very much. She struggled the last few years. I wish I could have helped.”

Sarah Michelle Gellar, who first met Trachtenberg on the ABC soap All My Children, ended up playing her older sister for three seasons on Buffy the Vampire Slayer. Gellar’s titular heroine was fiercely protective of her sensitive younger sister, Dawn, and their friendship endured well after the series wrapped in 2003.

“Michelle, listen to me,” Gellar wrote on Instagram the day after Trachtenberg’s death, quoting a monologue Buffy delivers to Dawn on the season 5 finale. “Listen. I love you. I will always love you. The hardest thing in this world, is to live in it. I will be brave. I will live… for you.”

Though Trachtenberg had slowed the pace at which she appeared in films and television shows in the last few years of her life, an associate revealed that she had recently been working to produce a “sharp, biting” screenplay she’d written.

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Trachtenberg had adapted Jerry Oppenheimer’s book Toy Monster: The Big, Bad World of Mattel into a script, Casey Tebo told PEOPLE , adding, “The only scripts I remember staying with me like that in recent memory were two. Here Comes the Flood by Simon Kinberg and Toy Monster around 2019. Because they were the two best, by a landslide.”

In the wake of Trachtenberg’s death, Tebo said he was “doing everything I can to get this movie made, we just need to find the right director, and I promise we will get it made for her.”