Smoking is detrimental for Fibromyalgia patients for several reasons.
Smoking reduces blood-oxygen content and impairs the already compromised muscle oxygenation further.
Nicotine is a potent muscle contractor and causes aggravation of muscle tension and spasm, leading to increased pain.
Nicotine is also a stimulant and increases the mental tension, which in turn intensifies preexisting muscular tension.
~Cabell Huntington Hospital
It makes sense that smoking would complicate the signals in the body and throw off any advances toward healing.