Role of population-based cohorts in understanding the emergence and progression of musculoskeletal pain

Association between pelvic pain bothersomeness and pain sensitivity: A community-based cross-sectional study of young adult females in the Raine Study

OBJECTIVE

Pelvic pain has been associated with augmented nociceptive processing, but large studies controlling for multiple potential confounding factors are lacking. This study investigated the association between pelvic pain bothersomeness and pain sensitivity in young adult women, accounting for potential confounding factors.

DESIGN

Cross-sectional study.

SETTING

Community-dwelling sample.

POPULATION

The Raine Study Gen2-22 year follow-up (n = 475).

MAIN OUTCOME MEASURES

The experience of bothersomeness related to pelvic pain was determined from a question in the Urogenital Distress Inventory short form. Pain sensitivity was measured using pressure pain and cold pain thresholds. Potential confounding factors included ethnicity, marital status, highest level of education, income, waist-hip ratio, level of activity, sleep quality, smoking, comorbidity history, C-reactive protein level, musculoskeletal pain experience and psychological distress.

RESULTS

Three hundred and sixty-two women (76.2%) reported no pelvic pain bothersomeness, 74 (15.6%) reported mild pelvic pain bothersomeness and 39 (8.2%) reported moderate-severe pelvic pain bothersomeness. After adjusting for marital status (and test site), moderate-severe pelvic pain bothersomeness was associated with a lower pressure pain threshold (i.e. greater pressure pain sensitivity) (coefficient -51.46, 95% CI -98.06 to -4.86, p = 0.030). After adjusting for smoking, moderate-severe pelvic pain bothersomeness was also associated with a higher cold pain threshold (i.e. greater cold pain sensitivity) (coefficient 4.35, 95% CI 0.90-7.79, p = 0.014).

CONCLUSIONS

This study suggests augmented nociceptive processing as a contributing factor in pelvic pain bothersomeness for some women. Thorough assessment of women who present clinically with pelvic pain should consider pain sensitivity as a potential contributing factor to their presentation.

Association of Biomarkers with Individual and Multiple Body Sites of Pain: The Johnston County Osteoarthritis Project

Introduction

Biochemical biomarkers may provide insight into musculoskeletal pain reported at individual or multiple body sites. The purpose of this study was to determine if biomarkers or pressure-pain threshold (PPT) were associated with individual or multiple sites of pain.

Methods

This cross-sectional analysis included 689 community-based participants. Self-reported symptoms (ie, pain, aching, or stiffness) were ascertained about the neck, upper back/thoracic, low back, shoulders, elbows, wrist, hands, hips, knees, ankles, and feet. Measured analytes included CXCL-6, RANTES, HA, IL-6, BDNF, OPG and NPY. A standard dolorimeter measured PPT. Logistic regression was used determine the association between biomarkers and PPT with individual and summed sites of pain.

Results

Increased IL-6 and HA were associated with knee pain (OR=1.30, 95% CI 1.03, 1.64) and (OR=1.32, 95% CI 1.01, 1.73) respectively; HA was also associated with elbow/wrist/hand pain (OR=1.60, 95% CI 1.22, 2.09). Those with increased NPY levels were less likely to have shoulder pain (OR=0.56, 95% CI 0.33, 0.93). Biomarkers HA (OR=1.50, 95% CI 1.07, 2.10), OPG (OR=1.74, 95% CI 1.00, 3.03), CXCL-6 (OR=1.75, 95% CI 1.02, 3.01) and decreased PPT (OR=3.97, 95% CI 2.22, 7.12) were associated with multiple compared to no sites of pain. Biomarker HA (OR=1.57, 95% CI 1.06, 2.32) and decreased PPT (OR=3.53, 95% CI 1.81, 6.88) were associated with multiple compared to a single site of pain.

Conclusion

Biomarkers of inflammation (HA, OPG, IL-6 and CXCL-6), pain (NPY) and PPT may help to understand the etiology of single and multiple pain sites.