“If I don’t play for a couple of days,” said Dr. Conrad, a third-year surgical resident at Harvard Medical School who also holds doctorates in stem cell biology and music philosophy, “I cannot feel things as well in surgery. My hands are not as tender with the tissue. They are not as sensitive to the feedback that the tissue gives you.”
Like many surgeons, Dr. Conrad says he works better when he listens to music. And he cites studies, including some of his own, showing that music is helpful to patients as well — bringing relaxation and reducing blood pressure, heart rate, stress hormones, pain and the need for pain medication.
The study itself was fairly simple. The researchers fitted 10 postsurgical intensive-care patients with headphones, and in the hour just after the patients’ sedation was lifted, 5 were treated to gentle Mozart piano music while 5 heard nothing.
The patients listening to music showed several responses that Dr. Conrad expected, based on other studies: reduced blood pressure and heart rate, less need for pain medication and a 20 percent drop in two important stress hormones, epinephrine and interleukin-6, or IL-6. Amid these expected responses was the study’s new finding: a 50 percent jump in pituitary growth hormone.
No one conducting these studies had yet measured growth hormone, whose work includes driving growth, responding to threats to the immune system and promoting healing. Dr. Conrad included it because research over the last five years has shown that growth hormone generally rises with stress and falls with relaxation.
“This means you would expect G.H., like epinephrine and IL-6, to go down in this case,” Dr. Morley, of St. Louis University, said of growth hormone. “Yet here it goes up.”
He added, “The question is whether the jump in growth hormone actually drives the sedative effect or is part of something else going on.”
Dr. Conrad argues that the growth hormone does have a sedative effect. In his paper he cites a 2005 study showing that growth hormone releasing factor, a chemical messenger that essentially calls growth hormone to duty, reduced activity of interleukin-6. This suggests, he said, that growth hormone itself may reduce the interleukin-6 and epinephrine levels that produce inflammation that in turn causes pain and raises blood pressure and the heart rate.
This explanation gets a mixed reception among stress researchers. “The two dynamics aren’t necessarily the same,” said Dr. Keith W. Kelley, an endocrinologist at the University of Illinois at Urbana-Champaign and an expert on inflammatory responses. “I personally don’t buy the particular cellular mechanism he’s proposing.”
Yet Dr. Kelley and other stress-response experts, including Dr. Morley and Dr. Bruce S. McEwen of Rockefeller University in New York, say Dr. Conrad’s study clearly suggests that a rise in growth hormone may somehow dampen inflammation and stress responses.
“This is a really intriguing possibility that bears a closer look,” Dr. McEwen said.