New York, Aug 16 (IANS): Long-term testosterone replacement therapy improves both sexual and urinary functions as well as quality of life for men suffering from a condition due to deficiency of the hormone, according to a study.

Testosterone is a steroid hormone involved in the regulation of sexual function, urinary health and metabolism as well as a number of other critical functions.

For most men, testosterone concentration declines slowly with age and may not cause immediate major symptoms.

However, some men may experience a host of signs and symptoms constituting a clinical condition called Testosterone Deficiency (TD), or male hypogonadism, which is attributed to insufficient levels of testosterone.

As a result, they experience symptoms as varied as erectile dysfunction, low energy, fatigue, depressed mood and an increased risk of diabetes.

The study, published in the Journal of Urology, investigated the effects of long-term testosterone replacement therapy on urinary health and sexual function as well as quality of life in men with diagnosed, symptomatic testosterone deficiency.

More than 650 men in their 50s and 60s enrolled in the study, some with unexplained testosterone deficiency and others with known genetic and auto-immune causes for their hypogonadism.

"It is thought that testosterone treatment in men may increase prostate size and worsen lower urinary tract symptoms," said Abdulmaged Traish, Professor of Urology at Boston University School of Medicine in the US.

However, the researchers discovered that despite increased prostate size in the group that received testosterone therapy, there were fewer urinary symptoms such as frequent urination, incomplete bladder emptying, weak urinary stream and waking up at night to urinate.

In addition to these subjective improvements, the researchers conducted objective testing that showed that those men treated with testosterone emptied their bladders more fully.

Finally, testosterone treatment also increased the scores patients received on assessments of their erectile/sexual health and general quality of life, the study said.