Elevated IGF-1

[jpringle]

Endocrine Related Question....

I am a 29 yr old female with osteoporosis (yes, I know I am young for this). I was sent to endocrine to try to see why. Everything has been normal except my Somatomedin C (IGF-1) is elevated at 358 (up 29 pts) and my cortisol level (24 hr urine) was low.  What would elevated IGF-1 & low cortisol levels mean, could this contribute to my osteoporosis?  I am waiting on my endocrinologist to call back and I want to have as much info as possible so that I can ask educated questions. Any help you can contribute is greatly appreciated!

Thank you,
Jennifer

[Mark Lupo, M.D.]

Some commercial labs (particularly Quest) run slightly high IGF-1's -- may not be significant, but if a repeat is still high then would need an oral glucose tolerance test with measurements of growth hormone and glucose every 30 minutes for 3 hours -- the endo will know about this.  A low 24h cortisol means you don't have Cushings.  It does not mean there is an under-active adrenal.  Would test parathyroid, thyroid, vitamin D and calcium if not already done.  Also if you had a history of no menses or an eating disorder during adolescence or in your 20's that may contribute to low bone mass.  So could use of steroids for treating things like asthma, etc...  

[jpringle]

Thank you for your response, your information is very helpful. Here is a little more information in response to your comments...

My PTH has occasionally been high, Vitamin D was low but is being treated and is stable (stable for 5 yrs now), calcium is normal, and all other thyroid tests are normal. The only other abnormal level is occasionally a slightly low white cell count. No history of an eating disorder, use of steroids or Depo injection (known to lower bone mass). I do have an absent menses (don't get it unless I take a hormone pill). They say I have Polycystic Ovarian Syndrome (but no known cysts).  I also have numerous other health issues...- Joint Pain (Osteoarthritis in numerous joints), Headaches,Fatigue, Acne, Weight gain, High Blood Pressure (mostly only elevated diastolic- around 90)
Always cold but difficulty in high heat, Palpitations, Depression, Raynauds
and eye issues (they question early glaucoma due to  large sized hole in my optic nerve, all tests are stable at this point).

At this point my endocrine is unsure what is going on. I am waiting for further instructions. Thank you for your help thus far, any other insight is appreciated!

Take Care,
Jen