Here you go Art for commentary:
Doctors often recommend that men with erectile dysfunction have their testosterone measured from 8 a.m. to 11 a.m., because levels are usually highest then and vary over a 24-hour period. But a new study has found that this variation occurs only in younger men.
Researchers retrospectively studied records of 2,569 men ages 26 to 84 who were evaluated at an erectile dysfunction clinic from 1985 to 2004. They sorted them into age groups, starting with 26- to 39-year-olds, and then in five-year groups up to age 84. They further divided them into two time groups: those who had their testosterone measured from 7 a.m. to 9 a.m. and those measured from 9 a.m. to 2 p.m. All the men had erectile dysfunction, a symptom of low testosterone levels.
The only men who showed a statistically and clinically significant decrease in levels between the two time periods were those younger than 45.
The lead author, Dr. Charles Welliver, a fellow at Southern Illinois University School of Medicine when the work was done, said that the timing of the test was unimportant for most men. “As long as the draw is done before 2 p.m.,” he said, “the value is still considered valid, except for the youngest two groups of men seen in this study.”