Hawaii Sen. Daniel Inouye hospitalized

Rachel Rose Hartman

Hawaii Democratic Sen. Daniel Inouye, 88, was hospitalized late last week and transferred to Walter Reed National Military Medical Center on Monday, his office announced late Monday.

"For the most part, I am OK," Inouye said in a widely circulated statement. "However, I am currently working with my doctors to regulate my oxygen intake. Much to my frustration, while undergoing this process, I have to remain in the hospital for my own safety and to allow the necessary observation."

Inouye, the longest-serving current senator, had a portion of his left lung removed in the 1960s when he was misdiagnosed with cancer.