Researchers from Michigan State University are studying whether pregnancies, specifically cesarean-section deliveries, are linked to a degenerative back disease that affects women three to nine times more often than men.
Degenerative spondylolisthesis, a condition in which a vertebra slips forward onto a bone below it, can cause lower back pain, muscle tightness and nerve damage, said Jacek Cholewicki of the College of Osteopathic Medicine.
He and colleague Lawrence Mysliwiec are leading a two-year, $407,000 project funded by the National Institutes of Health to examine the relationships between routine and cesarean section pregnancies, trunk and abdominal muscle weakness and the disease in older females.
"The costs associated with the treatment of degenerative low back disease make it one of the top five most expensive conditions in American health care," said Cholewicki, also co-director of MSU's Center for Orthopedic Research at Ingham Regional Orthopedic Hospital in Lansing. "And degenerative spondylolisthesis is considered one of the major causes of low back pain among the older population."
More importantly, women suffer from the disease at a rate up to nine times higher than men, without a clear explanation, he said. Previous studies have documented relationships between pregnancy and low back pain, with abdominal muscle deficiency as an underlying cause.
"Our key question is whether pregnancy and/or muscle deficiency caused by a cesarean delivery could be a precipitating factor in the development of degenerative spondylolisthesis later in life," Cholewicki explained.
"Since the rates of cesarean delivery rose three-fold during the past three decades, we are specifically interested in women undergoing those surgeries; a link could foretell significant public health problems in coming years."
As part of the project, Cholewicki and Mysliwiec are conducting a study of 200 patients with degenerative spondylolisthesis and 200 members of an age-matched control group. The subjects will answer detailed questionnaires, with a subset of 80 from each group undergoing extensive physical examinations of muscle in the abdomen and back as well as evaluation of motor control.
"The innovative aspect of this proposal is that we will quantify muscle function objectively and then document the variables in women with and without the disease," Cholewicki said. "This will give us a better chance of finding any relationships that might exist."