Individuals with fibromyalgia had lower sleep quality and efficiency, as well as longer wake time after sleep start, shorter sleep duration, lighter sleep, and greater trouble initiating sleep when objectively assessed, and more difficulty initiating sleep when subjectively assessed. Sleep problems may contribute to pain by decreased release of IGF-1 and human growth hormone, leading to decreased tissue repair. Improving sleep quality can help people with fibromyalgia minimize pain. Cognitive problems
Many people with fibromyalgia experience cognitive problems (known as "fibrofog" or "brainfog"). One study found that approximately 50% of fibromyalgia patients had subjective cognitive dysfunction and that it was associated with higher levels of pain and other fibromyalgia symptoms. The American Pain Society recognizes these problems as a major feature of fibromyalgia, characterized by trouble concentrating, forgetfulness and disorganized or slow thinking. About 75% of fibromyalgia patients report significant problems with concentration, memory, and multitasking. A 2018 meta-analysis found that the largest differences between fibromyalgia patients and healthy subjects were for inhibitory control, memory, and processing speed. It is hypothesized that the increased pain compromises attention systems, resulting in cognitive problems. Hypersensitivity
In addition to a hypersensitivity to pain, patients with fibromyalgia show hypersensitivity to other stimuli, such as bright lights, loud noises, perfumes and cold. A review article found that they have a lower cold pain threshold. Other studies documented an acoustic hypersensitivity. Comorbidity
Fibromyalgia as a stand-alone diagnosis is uncommon, as most fibromyalgia patients often have other chronic overlapping pain problems or mental disorders.
Aminolevulinic acid dehydratase (porphobilinogen synthase, or ALA dehydratase, or aminolevulinate dehydratase) is an enzyme (EC 4.2.1.24) that in humans is encoded by the ALAD gene. Porphobilinogen synthase (or ALA dehydratase, or aminolevulinate dehydratase) synthesizes porphobilinogen through the asymmetric condensation of two molecules of aminolevulinic acid. All natural tetrapyrroles, including hemes, chlorophylls and vitamin B12, share porphobilinogen as a common precursor. Porphobilinogen synthase is the prototype morpheein. Function
It catalyzes the following reaction, the second step of the biosynthesis of porphyrin:

2 5-Aminolevulinic acid 
  
    
      
        ⇌
      
    
    {\displaystyle \rightleftharpoons }
   porphobilinogen + 2 H2OIt therefore catalyzes the condensation of 2 molecules of 5-aminolevulinate to form porphobilinogen (a precursor of heme, cytochromes and other hemoproteins). This reaction is the first common step in the biosynthesis of all biological tetrapyrroles. Zinc is essential for enzymatic activity. Structure
The structural basis for allosteric regulation of Porphobilinogen synthase (PBGS) is modulation of a quaternary structure equilibrium between octamer and hexamer (via dimers), which is represented schematically as 6mer* ↔ 2mer* ↔ 2mer ↔ 8mer. The * represents a reorientation between two domains of each subunit that occurs in the dissociated state because it is sterically forbidden in the larger multimers. PBGS is encoded by a single gene and each PBGS multimer is composed of multiple copies of the same protein.