(CNN) — Georgia Republican Sen. Johnny Isakson will resign at the end of year, he announced Wednesday, citing health concerns. “After much prayer and consultation with my family and my doctors, I have made the very tough decision to leave the U. S. Senate at the end of this year. I have informed Georgia Governor Brian Kemp today that I will resign my Senate seat effective December 31, 2019,” Isakson said in a statement. “I am leaving a job I love because my health challenges are taking their toll on me, my family and my staff. My Parkinson’s has been progressing, and I am continuing physical therapy to recover from a fall in July. In addition, this week I had surgery to remove a growth on my kidney,” he added.