Childless men are more likely to die from cardiovascular disease than for fathers, says a large study by the Stanford University School of Medicine. Michael Eisenberg, MD, assistant professor of urology at Stanford, and his colleagues followed 135,000 male married or previously married members of the American Association of Retired Persons for an average of about 10 years. At the beginning of the study, the participants, whose average age was about 62.7, had no history of heart disease, and 92 percent had fathered at least one child. Half had three or more children. During the course of the study, 3,082 men died due to cardiovascular causes. That represented a 17 per cent increase in the likelihood of a childless man's dying of a condition related to cardiovascular disease, compared with fathers. The genders of the children a man had fathered made no difference in the likelihood of his succumbing to cardiovascular disease. "It's possible that many other factors besides testosterone account for fathers' lower cardiovascular risk. Maybe having children causes men to have healthier behaviors, so fathers will live longer," said Eisenberg.