Anti-Thyroid Antibody Potentially Predicts Chronic Hand Pain in Older Adults

Anti-thyroid peroxidase antibody (TPO-Ab) levels are potentially associated with chronic hand pain in patients older than 60 years, according to study findings in Therapeutic Advances in Musculoskeletal Disease. 

Researchers conducted a cross-sectional study to assess the association between chronic hand pain and autoimmune thyroid disease- (AITD-) associated antibodies. AITD autoantibodies, TPO-Abs, and anti-thyroglobulin antibodies (TgAbs) were identified as common antibodies found in patients with AITD. 

Data from phase I and II of the Third National Health and Nutrition Examination Survey (NHANES III) was analyzed for patients who completed The Household Adult Questionnaire (HAQ). Some patients included in the study also completed the Mobile Examination Centers portion of the study, where patients were examined by a physician. 

Of the 39,695 patients in the original sample who were interviewed in NHANES III, 6596 patients completed the HAQ. The final analysis included 4820 patients with hand pain with anti-thyroid antibody data available. 

The primary outcome was the presence of chronic hand pain, defined as pain in the hands on most days for the last 6 weeks, including stiffness and aching. Among all study participants, the rate of hand pain was reported as 18.8%.

Levels of TPO-Ab ranged from 0.30 U/mL (negative TPO-Ab) to 3000 U/mL (mean, 11.98 U/mL) and TgAb ranged from 0.70 U/mL (negative TgAb) to 3000.00 U/mL (mean, 12.59 U/mL). The majority of study patients had negative TPO-Ab (81.2%) or negative TgAb (84.8%).

Older adults with positive TPO-Ab experienced higher rates of hand pain compared with those with negative TPO-Ab based on unadjusted models (prevalence ratio [PR], 1.158; 95% CI, 1.00-1.34; P =.048). However, when adjusting for age, BMI, gender, and diabetes, this association was found to be insignificant (P =.313). 

TPO-Ab levels were stratified to assess the dose-dependent effects on chronic hand pain. There was a high prevalence of hand pain among older adults with higher levels of TPO-Ab than those with negative TPO-Ab levels (PR, 1.489; P =.005).

When TPO-Ab was assessed as a continuous variable, C-reactive protein levels were positively associated with TPO-Ab (R², 0.008; P <.001). There was no relationship between C-reactive protein and thyroid stimulating hormone. 

Adults with a history of thyroid disease reported hand pain in a greater proportion (26.6%) than those without thyroid disease (17.9%; P =.009). There was no relationship between TSH and serum thyroxine levels. 

Study limitations include restricting data to patients aged 60 years and older, limited generalizability, and the potential for major differences in population views due to the use of modern chemiluminescent assays.

“The possible sources of pain could include joint pain through degenerative joint disease, frank inflammatory arthritis, or neuropathic pain and would need to be investigated further in future studies,” the study authors wrote.