16 January 2002

Girls fare better than boys following heart surgery

A recent study published in Critical Care examined the role of molecules, known as cytokines, in the recovery of children following heart surgery. The study found that girls had higher levels of cytokine IL-10, which meant that they recovered more easily from their operations than boys.

In order to repair heart defects surgeons need a bloodless and motionless environment in which to work. This is achieved by diverting blood from the heart and lungs through a machine, which infuses the blood with oxygen and pumps it around the body. During this process, known as cardiopulmonary bypass, the patient's blood is in contact with a foreign environment, which can stimulate the immune system to cause inflammation throughout the body (systemic inflammation) leading to widespread cell damage and sometimes death.

Cytokines are chemicals that can increase or decrease systemic inflammation. Their release is stimulated by the female sex hormone, progesterone. Andreas Trotter and colleagues from the University of Ulm in Germany decided to look at the levels of progesterone and cytokines in children, during and after heart surgery, to see if increased levels were associated with the development of systemic inflammations.

The researchers found that female patients had higher levels of cytokine IL-10, both during and after surgery. This is of great interest because IL-10 is thought to be one of the cytokines that suppress inflammation, which may explain why girls recovered more easily than boys. However, Trotter could not find an association between the levels of progesterone and the recovery of the patients.

These results highlight that the role of sex hormones in systemic inflammation requires further study. They also show that there can be reasons for treating female and male patients differently. If female sex hormones really protect against the development of systemic inflammation then corrective cardiac surgery in girls should be carried out in the first weeks after their birth when their sex hormone levels are higher than those found later in infancy.

This research article is freely available in Critical Care, a journal published by BioMed Central, simply visit: http://www.biomedcentral.com/1364-8535/5/343

This research is also discussed in a commentary by Dr Marie-Christine Seghaye and colleagues in the same issue of Critical Care, for access to this article visit: http://biomedcentral.com/ccf/cc-5-6-280.pdf

Any articles published using the material featured in these articles should reference Critical Care, a journal published by BioMed Central. To read further press releases from BioMed Central visit: http://www.biomedcentral.com/info/pr-releases.asp

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