By Adrienne Dellwo, About.com Guide June 22, 2011:
A recently published hypothesis raises the possibility that an enzyme involved in type-1 diabetes may also be an underlying cause of fibromyalgia (FMS).
The enzyme is glutamic acid decarboxylase (GAD) -- specifically, a form called GAD65. It's primary job is to help turn a neurotransmitter (chemical messenger in the brain) called glutamate into another neurotransmitter called GABA. Glutamtate is an excitotoxin, meaning it gets areas of the brain over stimulated to potentially dangerous levels, while GABA calms the brain. Some research shows that FMS involves an imbalance of these two chemicals.
In the journal Medical Hypotheses, researchers lay out several reasons they believe problems with GAD levels or activity could play a critical role in this condition:
Mice without GAD65 develop hyperalgesia, which is a key symptom of FMS;
GAD plays a role in other disorders involving muscle stiffness and rigidity, similar to the morning stiffness common in FMS;