The primary sex hormone in men is testosterone. It is produced by the testes and helps drive many processes in the male body including sperm production. But what most of us connect testosterone to is male aggression and sex drive. It is true, most males have higher libidos than women and most are a bit more aggressive, but testosterone may not be the only variable.
A study published in the Journal of Clinical Endocrinology and Metabolism looked at testosterone levels in men and made comparisons to libido. Men who had low libido and high libido were included in the study. Data was gathered on more than 1600 men age 40-70 multiple times over a 15 year period. The researchers also wanted to assess how testosterone levels change over time in the same individual.
They found that libido is in fact cooreleated with testosterone levels. But what is tricky about the results is that low libido did not necessarily mean low testosterone. This is because overall the levels of testosterone did not differ by any statistical amount, regardless of libido.
Libido did decline over the 15 year time period. Only 19 percent of men were classified as having low libido at onset, which then increased to 23 percent after 9 years and 28 percent after 15 years. Testosterone levels seemed to stay the same, or show very little change.
So the aurthors conclude that just because a man's libido is low does not necessarily mean the cause is testosterone deficiency and other causes should be explored before prescribing.
Posted by Dr. Christina Gutierrez on August 3, 2006 02:56 PM
