Testosterone vs Diabetes: What's the Link? Part 2

You'd think I have no imagination since I keep on re-using titles w/Part 2, Part 3, Part 4, etc.  But it's all in the timing.  Plus, as I've said before, I don't make the news (I'm not good enough for that), I just report it.  And at least this time, I'm actually current & up-to-date.  If you'll recall, I wrote 2 days ago about an article in last month's Journal of Clinical Endocrinology & Metabolism (JCEM) that reviewed the literature regarding the (modest) link between testosterone (T) and type 2 diabetes (T2DM).  Well, the truth is how you spin it, right?  So hot off the presses in this month's issue of JCEM is an update on the link between hypogonadotropic hypogonadism (that's low T to you & me) and T2DM.

In fact, the authors reported that recent studies have demonstrated that 1 out of 4 men w/T2DM have low T w/inappropriately low LH & FSH. while a smaller number have low T w/elevated LH & FSH.  More importantly, they reminded me that the Endocrine Society's Clinical Practice Guideline has recommended screening for hypogonadism on a routine basis in all men w/T2DM (Table 3) since 2006 and again in 2010.  The authors also reminded me that men w/low T have 2-3x risk of cardiovascular events & death compared to those w/normal levels.

These same authors interpreted recent short-term studies of testosterone therapy as improving insulin sensitivity, decreasing waistline (central obesity or visceral adiposity), and increasing libido but without improving erectile function, glycemic control, cholesterol & C-reactive protein.  Accordingly, they recommended trials of longer duration to determine the risk:benefit ratio for the use of testosterone therapy in T2DM.

But what does this mean for you and me?  And what are we to make of LH & FSH?  Well, if they're low, we worry about pituitary dysfunction, but if they're high, we worry about testicular function.  In the former situation, if total T <150ng/dL (that's really low!), or prolactin is high, or headache or visual field defect is present, then the Endocrine Society recommends imaging the pituitary and hypothalamus.  Assuming that these conditions don't apply, no consideration is given to stimulate the testes to produce testosterone, thereby placing younger patients at risk of future infertility.

That's why I feel that it's important for clinically symptomatic hypogonadal men to seek out American Board of Medical Specialties-certified physicians (regardless of specialty) who are familiar with the various (on & off-label) therapeutic options and can offer treatment tailored to their individual needs, not just a cookie cutter approach of intramuscular testosterone for everyone.  Luckily, the Endocrine Society agrees w/me on this last point (see Table 6).  In fact, the Clinical Guideline is a great review on the topic which I recommend to both physician and patient.