Could my generalized stiffness be due to phosphate deposition in soft tissues from a genetically impaired renal phosphate clearance associated with fibromyalgia?

The Phosphate Deposition Theory in Fibromyalgia is Not Supported by Medical Evidence

The concept that fibromyalgia involves phosphate deposition in tissues due to impaired renal phosphate clearance is not recognized in current medical literature and does not explain your generalized stiffness. This theory lacks any scientific foundation in established fibromyalgia research or clinical guidelines.

What Actually Causes Stiffness in Fibromyalgia

Central Nervous System Dysfunction

• Fibromyalgia is understood as a disorder of central pain amplification, where the central nervous system malfunctions in processing and interpreting pain signals 1
• The stiffness you experience results from central sensitization mechanisms, not from any tissue deposition of minerals 2

Metabolic Abnormalities in Muscle (Not Phosphate Deposition)

• Research has identified mitochondrial dysfunction in fibromyalgia muscles, with significantly lower phosphocreatine (PCr) and ATP levels detected by magnetic resonance spectroscopy 3
• Studies show reduced high-energy phosphate levels within muscle cells, not phosphate deposits in tissues 4
• Fibromyalgia patients demonstrate abnormal glycolysis with increased pyruvate and decreased lactate production, along with decreased ATP in erythrocytes 5
• These represent intracellular energy metabolism problems, fundamentally different from extracellular phosphate deposition 3

Why Phosphate Deposition Theory is Incorrect

Renal Function is Normal in Fibromyalgia

• There is no evidence of genetic impairment in renal phosphate clearance in fibromyalgia patients
• Phosphate deposition in soft tissues occurs in specific, well-defined conditions that are completely distinct from fibromyalgia:
  • Chronic kidney disease with hyperphosphatemia causes soft tissue calcification when kidneys cannot clear phosphate 6
  • X-linked hypophosphatemia involves renal phosphate wasting (excessive loss), not retention, causing hypophosphatemia and osteomalacia 6
  • Tumor lysis syndrome causes acute hyperphosphatemia with calcium-phosphate crystal deposition in renal tissue 6

The Biochemistry Doesn't Match

• Conditions with true phosphate tissue deposition present with hyperphosphatemia (elevated blood phosphate) and require dialysis for management 6
• X-linked hypophosphatemia causes hypophosphatemia (low blood phosphate) with renal wasting, presenting with rickets, osteomalacia, and bone deformities—not fibromyalgia-type stiffness 6
• Fibromyalgia patients do not have abnormal serum phosphate levels or renal phosphate handling disorders

What Testing Would Show

If you had a phosphate-related disorder causing tissue stiffness, you would demonstrate:

• Abnormal serum phosphate levels (either elevated in CKD or decreased in hereditary phosphate wasting disorders) 6, 7
• Abnormal TmP/GFR (tubular maximum reabsorption of phosphate) indicating renal dysfunction 6, 7
• Elevated FGF23 levels in hereditary hypophosphatemic conditions 6, 7
• Radiographic evidence of soft tissue calcification (in hyperphosphatemic states) or rickets/osteomalacia (in hypophosphatemic states) 6
• Abnormal calcium metabolism and parathyroid hormone levels 6, 7

None of these findings are characteristic of fibromyalgia.

The Actual Pathophysiology of Your Stiffness

Your generalized stiffness in fibromyalgia results from:

• Central sensitization with altered neurotransmitter release (both excitatory and inhibitory) 2
• Peripheral sensitization involving altered nociceptor signaling 2
• Mitochondrial dysfunction causing reduced muscle energy metabolism with lower blood flow in affected muscles 3
• Genetic polymorphisms in serotoninergic, dopaminergic, and catecholaminergic systems 1

Common Pitfall to Avoid

Do not pursue testing for phosphate disorders or renal function abnormalities based on this unfounded theory. Such testing would be:

• Clinically inappropriate for fibromyalgia evaluation
• Unlikely to reveal any abnormalities
• A distraction from evidence-based fibromyalgia management involving multidisciplinary treatment with both pharmacological interventions (pregabalin, duloxetine, milnacipran) and physical therapy modalities 2, 1