A combination of 6 months of treatment with pyridostigmine and triweekly exercise fails to improve insulin-like growth factor-I levels in fibromyalgia, despite improvement in the acute growth hormone response to exercise.
OBJECTIVE
People with fibromyalgia (FM) often have low insulin-like growth factor-I (IGF-I) levels and a suboptimal growth hormone (GH) response to acute exercise. As previous work had demonstrated a normalization of the acute GH response to exercise with the use of pyridostigmine (PYD), we tested the hypothesis that 6 months of PYD therapy plus supervised exercise would increase IGF-I levels.


METHODS
Subjects with primary FM were randomized into 4 groups: (1) PYD/exercise; (2) PYD/diet recall; (3) placebo/exercise; and (4) placebo/diet recall. The dosing of PYD was 60 mg tid for 6 months. Resting IGF-I levels were measured at baseline and after 6 months of treatment. In addition the acute GH response to exercise at VO2 max was measured at baseline and after treatment.


RESULTS
A total of 165 FM subjects (mean age 49.5 yrs, 5 male) were entered and 154 (93.3%) completed the study. Six months of therapy (PYD plus exercise or exercise alone) failed to improve the IGF-I levels. The use of PYD 1 hour prior to exercise improved the acute GH response (4.54 ng/dl) compared to placebo (1.74 ng/dl) (p = 0.001) at the end of the 6-month trial. The acute GH response to exercise at baseline did not correlate with IGF-I, age, depression, medications, estrogen status, or obesity.


CONCLUSIONS
A combination of triweekly supervised exercise plus the daily use of PYD for 6 months failed to increase IGF-I levels in patients with FM, despite the confirmation that PYD normalizes the acute GH response to strenuous aerobic exercise.
Jones
Kim Dupree
KD
Schools of Nursing and Medicine, Oregon Health and Science University, Portland, Oregon, USA. jonesk@ohsu.edu
Deodhar
Atul A
AA
Burckhardt
Carol S
CS
Perrin
Nancy A
NA
Hanson
Ginger C
GC
Bennett
Robert M
RM
D002800:Cholinesterase Inhibitors / Q000627:therapeutic use*; D003131:Combined Modality Therapy; D004311:Double-Blind Method; D005081:Exercise Therapy; D005260:Female; D005356:Fibromyalgia / Q000097:blood / Q000503:physiopathology / Q000534:rehabilitation*; D013006:Growth Hormone / Q000097:blood*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011729:Pyridostigmine Bromide / Q000627:therapeutic use*; D017211:Treatment Failure; D016896:Treatment Outcome
D002800:Cholinesterase Inhibitors; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D011729:Pyridostigmine Bromide