From the San Diego Union Tribune
Risks seen if male sex hormone’s level low
UCSD researchers tackle testosterone
By Cheryl Clark
June 6, 2007
LA JOLLA ? Two UCSD researchers fear that after men hear about their study, which links low levels of testosterone to earlier death, they’ll wrongly think more must be better and beg their doctors for supplements of the male hormone.
The physicians might oblige, even if their patients aren’t testosterone-deficient. That would be a potentially harmful response to the study’s findings.
?Men want them; doctors make money prescribing them,? said Dr. Elizabeth Barrett-Connor, one of the study’s authors.
She and Gail Laughlin analyzed blood from nearly 800 men 50 and older who lived in Rancho Bernardo during the monitoring period. The researchers presented their report yesterday during the annual meeting of The Endocrine Society in Toronto.
?We’re not ready to say that men should go out and get testosterone to prolong their lives,? said Barrett-Connor, who directs the long-term Rancho Bernardo project. She and other researchers began tracking 6,000 Rancho Bernardo men and women in 1972 to see how lifestyle, diet, components in blood and weight might affect disease and life span.
The testosterone report is an outgrowth of the overall project.
It shows that men with low testosterone levels ? less than 250 nanograms per deciliter of blood ? had a 33 percent greater risk of dying at a younger age from various causes than men with medium or high levels.
The men with low testosterone levels also tended to have greater risk for diabetes, metabolic syndrome, cardiovascular disease and larger waist sizes than men in the other two categories. But their low testosterone preceded those conditions by many years.
The difference in mortality ?was not explained by the participants’ smoking, alcohol intake and level of physical activity or by pre-existing diseases such as diabetes and heart disease,? the authors wrote in a summary of their report.
Laughlin and Barrett-Connor don’t know why some of the study participants had low testosterone levels. It also remains unclear whether those men should get supplements.
The report found that men with higher levels of testosterone had the same longevity as men with medium levels.
?Our study did not find that higher levels of testosterone had any protective effect against (earlier) mortality,? Laughlin said.
In addition, among men with normal or high amounts of testosterone, supplements could raise levels of the hormone enough to aggravate undiagnosed cases of prostate cancer that otherwise wouldn’t be clinically relevant.
Ultimately, Laughlin and Barrett-Connor are calling for a more comprehensive clinical trial on testosterone’s effects.
Several endocrinologists in San Diego County said the study’s findings are provocative.
?I think a lot of us will be spending more time thinking about testosterone in our patients,? said Dr. Timothy Bailey in Escondido.
Between 1984 and 1987, Laughlin and Barrett-Connor took blood samples from study participants. The samples were frozen. In the mid-1990s, those samples were tested for testosterone levels.
During an average 12.4 years of follow-up from the time the blood was drawn, 538 of the men died.
Laughlin said the mortality process may start with low testosterone, which leads to larger waistlines, which eventually can cause metabolic syndrome and diabetes.
In recent years, studies have linked low testosterone to a variety of health problems, such as higher risk of falling, greater thickening of the walls of arteries that carry blood to the brain, Alzheimer’s disease and depression. But those studies were small-scale and short-term.
Despite the lack of solid scientific data, the use of testosterone supplements by men with normal levels of the hormone has mushroomed since the mid-1990s. Men take the supplements believing they will become more energetic, more muscular, younger, smarter and more sexually active.
?Major users are not old men who may have low testosterone, but men in their 40s or 50s or younger who feel their youthfulness and sexuality are not what they were,? Barrett-Connor said.
?But there’s almost no data to show that it works, and whether it would work in men who are 65 or over who want to play 18 holes of golf like they used to but can only play nine,? she added.
Two participants in the Rancho Bernardo project are Joyce and Lewis Brunn, who wanted to learn more about how to prevent osteoporosis when they joined in the early 1970s. She is 73; he is 75.
They said their involvement makes them feel as if they are contributing to an important medical effort.
?I never thought about the study in regards to testosterone,? Lewis Brunn said, adding that he hopes to find out more about the results.