Males are more at risk of thrombosis or blood clotting than women, particularly after heart attack and stroke, according to a study.

Ethan Weiss and colleagues at the University of California, San Francisco, have used a mouse model to shed new light on this condition.

Thrombosis-related proteins are made in the liver, where expression of the genes containing the information needed for their generation is regulated by growth hormone (GH), secreted in a sex-specific manner -- males secrete GH in a pulsatile fashion, whereas females secrete GH continuously.

GH-deficient mice were protected from thrombosis in the model of disease. When female GH-deficient mice were given pulsatile GH (to mimic the manner in which GH is secreted in males) their ability to form blood clots resembled male mice.

Conversely, when male GH-deficient mice were given continuous GH (to mimic the manner in which GH is secreted in females) their ability to form blood clots resembled female mice.

The authors, therefore, concluded that sex-specific patterns of GH release mediate gender-associated differences observed in susceptibility to diseases caused by inappropriate thrombosis, information that they hope will be of help in the development of sex-specific treatments for thrombosis, reports Sciencedaily.