The X Factor: Why Women May Be Healthier Than Men
The Reason Women Live Longer May Lie in Their Second X Chromosome
Sex Hormones Also Contribute to Gender Differences
Other factors such as sex hormones including estrogen and progesterone and the environment may also play a role.
“Genetic differences definitely matter and there is ongoing interest and evidence that having one or two X chromosomes can impact ... differences between the sexes resulting in differential susceptibility to autoimmune diseases and even viral infections,” says Sabra L. Klein, PhD. Klein wrote an editorial that accompanied the new study. She is an assistant professor of molecular microbiology and immunology at Johns Hopkins Bloomberg School of Public Health in Baltimore.
“There is an equally compelling body of work to show that hormones, including testosterone and estrogens, impact the functioning of the immune system to alter development of disease,” Klein says via email.
“We like rules of thumb and simple stories and the ... differences between the sexes is anything but simple and likely involves both genes and hormones,” she says. “Many differences are hardwired in our genes, but the magnitude of these differences when faced with challenges may be affected by our hormonal environment.”
Many questions remain. “Can we therapeutically manipulate the expression of our genes or concentrations of hormones to reverse susceptibility to disease? Can information about gene expression and hormonal environment be used to tailor treatments differently for men and women? Do we have to treat men and women differently in order to treat them equally?”
Michael D. Lockshin, MD, has been talking about the X factor for years. He directs the Barbara Volcker Center for Women and Rheumatic Disease at Hospital for Special Surgery in New York City.
When asked if it all boils down to the X, he says, “Yes I think so.”
That said, environment also affects how long we live and what diseases we develop. “There is much more to look for in the environment,” he says in an email.