Is hypermobile Ehlers-Danlos Syndrome (hEDS) associated with thyroid conditions?

Association Between Hypermobile Ehlers-Danlos Syndrome and Thyroid Conditions

Yes, there is a documented association between hypermobile Ehlers-Danlos Syndrome (hEDS) and autoimmune thyroid diseases (AITDs), with thyroid disorders being the most common concurrent autoimmune condition in patients with connective tissue disorders. 1

Evidence for the Association

The relationship between hEDS and thyroid conditions is supported by several key findings:

1. Prevalence of Thyroid Disorders in Connective Tissue Disorders:

   • Autoimmune thyroid diseases (AITDs) are the most common concurrent autoimmune condition associated with autoimmune connective tissue disorders (10-23%) 1
   • Hashimoto's thyroiditis accounts for approximately 10.2-14.1% of all concomitant autoimmune diseases in these patients 1
   • Graves' disease occurs in about 3-6% of patients with connective tissue disorders 1

2. Population-Based Evidence:

   • A South Korean study using the National Health Insurance Service data found thyroid disorders to be the most common concurrent autoimmune disease (10.5%) among 3,783 patients with connective tissue disorders 1

Clinical Implications

This association has important clinical implications for patients with hEDS:

Screening Recommendations

• Patients with hEDS should be monitored for symptoms of thyroid dysfunction, including:
  • Unexplained weight changes
  • Fatigue
  • Temperature intolerance
  • Changes in heart rate
  • Mood changes
  • Hair/skin changes

Diagnostic Considerations

• Thyroid function tests (TSH, free T4, free T3) should be considered in the workup of hEDS patients, especially those with symptoms suggestive of thyroid dysfunction
• Thyroid antibody testing (TPO antibodies, TRAb) may be warranted to identify autoimmune thyroid disease 2

Management Implications

• Proper management of thyroid conditions may help improve some symptoms that overlap with hEDS
• Patients with both conditions may require coordinated care between rheumatology and endocrinology

Pathophysiological Considerations

While the exact mechanism linking hEDS and thyroid conditions remains unclear, several hypotheses exist:

1. Shared Autoimmune Mechanisms: Both conditions may share underlying autoimmune pathways
2. Connective Tissue Involvement: Thyroid tissue contains connective tissue elements that may be affected in hEDS
3. Genetic Factors: There may be shared genetic susceptibility factors

Clinical Differentiation Challenges

It's important to note that symptoms of thyroid dysfunction can overlap with hEDS manifestations:

• Fatigue and exercise intolerance
• Joint pain
• Cognitive issues ("brain fog")
• Autonomic symptoms

This overlap can complicate diagnosis and management, making it essential to consider thyroid disorders in the differential diagnosis of worsening hEDS symptoms.

Monitoring Recommendations

For patients with hEDS:

• Consider baseline thyroid function testing at diagnosis
• Monitor for development of thyroid symptoms periodically
• Have a lower threshold for thyroid testing when symptoms change or worsen

The recognition of this association can lead to earlier diagnosis and more comprehensive management of both conditions, potentially improving quality of life and long-term outcomes for patients with hEDS.