"Exposure to environmental or passive tobacco smoke increased the risk of sickle cell crisis by 90 percent, and was not influenced by other factors known to increase complications, such as age of the patient or type of sickle cell disease," said Daniel C. West, associate professor of pediatrics at UC Davis and lead author of the study. "Exposure to tobacco smoke has a tremendous impact on children with sickle cell disease. In fact, the study suggests that removing passive tobacco smoke from the home might not only reduce the suffering of children with sickle cell disease, but also reduce the cost of medical care."
Sickle cell disease is a hereditary disease that affects hemoglobin, the protein in red blood cells that carries and delivers oxygen to tissues. The presence of sickle hemoglobin can lead to damaged and misshapen red blood cells that do not flow normally through blood vessels and deliver less than the normal amount of oxygen to peripheral tissues. These abnormalities can cause episodes of severe pain, known as sickle cell crises, and life-threatening damage to vital organs, such as the lungs and the brain.
Over a period of two years, researchers monitored 52 patients between the ages of 2 and 18 with several types of sickle cell disease.
Each patient or family completed an environmental survey and researchers recorded the number of sickle cell crises -- vaso-occlusive pain episodes, acute chest syndrome, stroke -- that required hospitalization.
The 22 children and adolescents who were exposed to environmental tobacco smoke experienced more than twice the number of sickle cell crises requiring hospitalization compared to those not exposed to tobacco smoke in the home.
As a secondary outcome, researchers found that the cost of hospitalization in the exposed group was more than triple the cost of hospitalization in the unexposed group.
West said, "If we can reduce smoking in family members, we may be able to significantly reduce the life-threatening complications of sickle cell disease in their children."
The UC Davis Sickle Cell Center is the only center located in inland Northern California. It serves a population of approximately 5 million people.
Copies of all news releases from UC Davis Health System are available on the Web at
UC Davis Medical Center is one of five University of California teaching hospitals. As the primary clinical education site for the UC Davis School of Medicine, and the only area provider of many medical services, the medical center is integral to the health and well-being of Northern Californians. Licensed for 576 beds and fully accredited, UC Davis Medical Center is home to the only level I pediatric and adult trauma center in inland Northern California, Alzheimer's Disease Center, NCI-designated Cancer Center, Children's Hospital, and regional burn center. As the only teaching hospital in the region, UC Davis supports a wide range of research projects that offer patients new diagnostic and treatment modalities. It's primary care network and outpatient clinics conduct more than 800,000 patient visits each year.
UC Davis Health System
4900 Broadway, Suite 1200
Sacramento, CA 95820
Web address: http://www.