Bioavailable Testosterone | Dr. Lawrence D. Komer Medical Professional Corporation

Dr. Lawrence D. Komer Medical Professional Corporation

Bioavailable Testosterone

Q. Is it common to find TT compensated by low SHBG so that the free T falls within the normal range? Should this be considered normal and just ignored?

Some background on me: 50 yr-old male, saw three endocrinologists over past 10 years, TT values ranged from 141 to 195 ng/dL, with normal range minimum around 240 ng/dL, not hypergonadatropic (no signs of Klinefelter’s, save eunochoid habitus with all height before puberty), low SHBG and low-normal free T (don’t remember the value, but once was below normal), no brain tumors (MRI), normal libido, but lifelong difficulty building muscle and recent diagnosis of anklyosing spondylitis. I’m not receiving any hormone therapy.

My low TT was first measured after I suspected it might be low–I had to practically beg my doctor to measure it. Ironically, the first two endocrinologists wouldn’t measured the free T–it took a rheumatologist to decide to test that.

A. Free testosterone is almost useless in assessing functional testosterone levels. SHBG tends to rise with age. The levels that have some value are Bioavailable testosterone and we base about 20% of our assessment on it and 80% on the symptoms the man is having. We have developed our own questionnaire to assess this.

Some Endocrinologist get bogged down on treating blood tests and not patients. A big factor that cannot be assessed by blood work is the sensitivity of the testosterone receptors in the cells. If the receptors have become insensitive, then even normal levels or testosterone will not work well. I believe that that is why this is a clinical and not blood diagnosis and this is what I teach to my residents and interested family practitioners.

Ankylosing spondilitis is not affected by testosterone levels.