| Term 
 
        | normal total testosterone: |  | Definition 
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        | Term 
 
        | normal Bioavailable Testosterone: |  | Definition 
 
        | - gold standard for measuring testosterone - 40% of testosterone
 - 120-600 ng/dL= normal
 |  | 
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        | Term 
 
        | Normal hypogonadism due to aging: |  | Definition 
 
        | - all components of Testosterone decrease with aging - decline in Leydig cell count/function
 - increase in SHBG
 - not all men with low T need tmt
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        | Term 
 
        | Serum Total Testosterone: |  | Definition 
 
        | -  morning sample - needs to be done twice
 - < 300 ng/dL suggests hypogonadism
 |  | 
        |  | 
        
        | Term 
 
        | Serum free testosterone is a better test for __ and __ men. Less than __ is hypogonadism. |  | Definition 
 
        | - obese and older men - less than 50 ng/mL
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