Andropause Diagnosis
Blood Tests Measure Testosterone Levels in Diagnosis of Andropause
A blood test is needed to diagnose andropause. After the age of 50, the average testosterone level decreases at a rate of approximately 1% per year. However, if only absolute testosterone levels are evaluated, many patients with andropause will be missed.
There may be an increased level of sex hormone-binding globulin that binds the testosterone and makes less of it available to the tissues. Also, as men get older, there is less of a daily rhythm to the secretion of the testosterone. Younger men have higher testosterones in the morning, which then decrease as the day wears on. In older men, this curve is flattened, leading to steady low levels of testosterone throughout a 24-hour period.
Here are some issues regarding testosterone that are important to remember:
- It is not yet known what level of serum testosterone defines a deficiency in older men. Generally, it is accepted that two standard deviations below the normal values for young men is considered abnormal.
- A man may have large variations in his serum testosterone levels over time. He may have normal testosterone levels one day and have decreased testosterone levels the next, so it is important to look at hormone levels over a period of time.
- In older men, affected organs may respond differently to androgens.
Not all men need the same level of testosterone to maintain proper function of their brain, bone, prostate or muscle cells. Therefore, it would be incorrect to say that there is one standard level of testosterone that should be achieved by all men. Rather, the patient and the physician working together need to find the level of testosterone that is most effective for the particular patient.
What is the Best Way to Measure Testosterone Levels and Diagnose Andropause?
There remains significant controversy as to how best to measure testosterone levels and diagnose andropause. It is well accepted that if total testosterone is less than 200 ng/dl, a man will be considered as having a low testosterone level. If his total testosterone is greater than 600 ng/dl, low testosterone may be ruled out.
Currently, it appears that the best measurement of androgen status is either "free testosterone" or "bioavailable testosterone." However, these can be measured in different ways. The analog free testosterone method is the most commonly used in the United States by most large commercial labs. It is not considered a very accurate way of measuring testosterone. The best measurement of hormonal status is either free testosterone or bioavailable testosterone. These measurements may only be available through specialty laboratories.
It is important to remember that there is significant variation in the recommendations of what tests should be used to establish a biochemical diagnosis of andropause. However, it is widely accepted that the blood work should be done in the morning before ten o'clock to capture the potential peak values.
Since testosterone interpretation is such a complicated field, it is helpful to see a specialist for an andropause diagnosis. These experienced physicians have a relationship with a specialty lab as well as the experience to interpret these complicated results.
