Comorbid Conditions Do Not Differ in Children and Young Adults with Functional Disorders with or without Postural Tachycardia Syndrome

Objective To determine if several multisystem comorbid conditions occur more frequently in subjects with tilttable defined postural tachycardia syndrome (POTS) compared with those without. Study design Retrospective chart review of 67 subjects aged 6-24 years, referred to a tertiary care neurogastroenterology and autonomic disorders clinic for a constellation of functional gastrointestinal, chronic pain, and autonomic complaints. All patients underwent formal autonomic testing, Beighton scores assessment for joint hypermobility (0-9), and fibromyalgia tender points (0-18) (43 subjects). Results Twenty-five subjects (37%) met tilt table criteria for POTS. The median age of 16 years (range, 12-24 years) in the POTS group differed from 15 years (range, 6-21 years) in the no-POTS group (P = .03). Comorbidities including chronic fatigue, sleep disturbances, dizziness, syncope, migraines, functional gastrointestinal disorders, chronic nausea, fibromyalgia, and joint hypermobility did not differ between groups. All subjects with fibromyalgia by tender point-examination had a Beighton score >= 4 (P = .002). Conclusions Comorbid conditions are equally prevalent in children and young adults with and without tilt-table defined POTS, suggesting that POTS itself is not a cause of the other comorbidities. Instead, POTS likely reflects another comorbid condition in children with functional disorders. Dizziness and syncope, classically associated with POTS, are not predictive of a diagnosis of POTS by tilt table, a test that is still required for formal diagnosis. These results suggest a paradigm shift in the concept of POTS as the physiological basis of many functional symptoms.