Having heart surgery later in the day may be safer than having it in the morning. Researchers studied 596 patients, half of whom had undergone open-heart surgery for aortic valve replacement in the morning and half in the afternoon. They followed their recoveries for 17 months. On almost every measure — heart attack during the operation, major adverse cardiac event, acute heart failure, cardiovascular death — afternoon surgery produced significantly fewer complications. The study is in Lancet. The genetic mechanisms that protect tissue under stress function differently in the morning and the afternoon — in all organs, not just the heart — and the authors believe that these circadian variations account for their findings.

Chronic inflammation may affect brain

Chronic inflammation in middle age may be associated with an increased risk for brain shrinkage and Alzheimer’s disease later in life. A new study looked at 1,633 people in 1987-89, measuring white blood cell count and various blood proteins that indicate inflammation. In 2011-13, the scientists measured their brain volume using MRI and tested their mental agility with a word-memorization task. They found that the greater the number of elevated inflammatory markers earlier in life, the smaller the volume of several parts of the brain, including those associated with Alzheimer’s disease.

New York Times