After struggling with life-threatening health issues earlier this year, Kenneth Bae, of Lynnwood, may be sent back to a North Korean labor camp, according to CNN, which cites a pro-North Korea Japanese newspaper.

Bae, who’s been North Korea’s longest-held U.S. captive since the Korean War, pleaded for quick intervention while wearing a blue labor-camp uniform in a video interview obtained by CNN this week. Complications from diabetes, an enlarged heart and back problems prompted his hospitalization from August to January, and then again at the end of March.

“My main concern right now is my physical condition,” Bae said in the video. “Doing hard labor for eight hours a day for the next couple months will be difficult.”

Bae’s family, which includes three children, asked that his supporters pray for his health at 7 p.m. Friday, his 46th birthday. He had problems with his lungs and liver during his last hospital stay, said his sister, Terri Chung.

While still thankful for efforts made so far to negotiate a release in the past, Bae’s family asked the U.S. government Thursday to increase efforts to save him before his declining health continues to cause irreparable damage or even death.

The latter fate is not uncommon in North Korean prisons called gulags. Prisoners often die of inhumane treatment that includes starvation.

Several attempts to negotiate for his release from the Democratic People’s Republic of Korea (DPRK), including a hope that celebrity Dennis Rodman might be able to use “basketball diplomacy” to change North Korean dictator Kim Jong Un’s mind, have failed so far.

“We’re told (the U.S. Department of State is) working on things behind the scenes, and we believe that, but we respectfully request those efforts be increased,” Bae’s sister said Thursday. “We don’t think his body can take it, this yoyo-ing from prison to hospitalization for several months.”

State Department spokeswoman Marie Harf said Thursday the department is in regular contact with Bae’s family.

“We are very concerned about his health. We have urged the DPRK authorities to grant him special amnesty and immediate release on humanitarian grounds. And look, I would just take with a grain of salt things people say in videos when they are being held by a country like North Korea,” she told reporters in Washington.

Chung has taken leave from her job as an English instructor at North Seattle College to pursue efforts to bring her brother back full time. She says her new full-time advocacy effort consists of never-ending letter-writing campaigns, promoting the #bringBaeback hashtag on social media, and meeting with members of the U.S. government who might be able to help.

Friday, it will include sharing a birthday cake for Bae with people helping Chung try to win his release.

“I’ve been to (Washington) D.C., twice this year to secure meetings at the State Department,” Chung said. “It’s an endless search for contacts who could help — which door can I knock down that might have more influence in the U.S. government. Who has more decision-making power?”

North Korea sentenced Bae, a Christian, to 15 years of hard labor in May 2013 for what it termed “hostile acts” against the regime. He was arrested in November 2012 while leading the kind of tourism trip he’d led several times before in Rason, a city in North Korea.

Bae is one of three Americans being held in North Korea; Matthew Miller Todd was taken into custody in April, and Jeffrey Fowle in June, according to CNN.

Chung says news that Bae might be back at a labor camp came as a devastating shock Thursday morning. She said his U.S.-based family hadn’t received an update on his condition since April and now fears for his life more than ever.

“We’ve been in a sort of black hole of information since then,” Chung said. “It’s hard to know for sure what the State Department is planning to do to help him, but whatever it is, it needs to be now. We can’t afford to waste any more time.”

Information from The Associated Press was included in this report.Alexa Vaughn: 206-464-2515 or avaughn@seattletimes.com. On Twitter @AlexaVaughn.