Enhanced Pain Sensitivity Among Individuals With Symptomatic Knee Osteoarthritis: Potential Sex Differences in Central Sensitization

Expanded Distribution of Pain as a Sign of Central Sensitization in Individuals With Symptomatic Knee Osteoarthritis

BACKGROUND

Expanded distribution of pain is considered a sign of central sensitization (CS). The relationship between recording of symptoms and CS in people with knee osteoarthritis (OA) has been poorly investigated.

OBJECTIVE

The aim of this study was to examine whether the area of pain assessed using pain drawings relates to CS and clinical symptoms in people with knee OA.

DESIGN

This was a cross-sectional study.

METHODS

Fifty-three people with knee OA scheduled to undergo primary total knee arthroplasty were studied. All participants completed pain drawings using a novel digital device, completed self-administration questionnaires, and were assessed by quantitative sensory testing. Pain frequency maps were generated separately for women and men. Spearman correlation coefficients were computed to reveal possible correlations between the area of pain and quantitative sensory testing and clinical symptoms.

RESULTS

Pain frequency maps revealed enlarged areas of pain, especially in women. Enlarged areas of pain were associated with higher knee pain severity (rs=.325, P<.05) and stiffness (rs=.341, P<.05), lower pressure pain thresholds at the knee (rs=-.306, P<.05) and epicondyle (rs=-.308, P<.05), and higher scores with the Central Sensitization Inventory (rs=.456, P<.01). No significant associations were observed between the area of pain and the remaining clinical symptoms and measures of CS.

LIMITATIONS

Firm conclusions about the predictive role of pain drawings cannot be drawn. Further evaluation of the reliability and validity of pain area extracted from pain drawings in people with knee OA is needed.

CONCLUSION

Expanded distribution of pain was correlated with some measures of CS in individuals with knee OA. Pain drawings may constitute an easy way for the early identification of CS in people with knee OA, but further research is needed.

Sex differences in symptom severity and clusters in patients with stage C4 and stage C5 chronic venous disease

BACKGROUND

Multiple symptoms associated with chronic venous disease (CVD) are poorly understood, under-recognized, and ill-managed.

AIMS

The aim of this study was to determine whether there are differences in symptoms and symptom clusters between men and women with stage C4 and stage C5 CVD.

METHODS

Data were collected via interviews with 264 patients using a demographic survey and an 11-item VEINES-SYM questionnaire.

ANALYSIS

An intrinsic scoring algorithm was developed to calculate the overall t scores for each item by sex. Exploratory factor analysis identified symptom clusters using oblique rotation to account for correlations between factors.

RESULTS

The average age was 61.7 years; 54.5% of the patients were women, 58% were African American or black, and 60.6% had diabetes. The top three symptoms for women in order of frequency were achy legs, swelling, and pain; for men, these were swelling, achy legs, and heavy legs. For the total group, two symptom clusters emerged: distressful and discomfort. There was no statistically significant difference in factor score between the sexes. Different factor loadings for symptom clusters were observed: women reported hurting and annoying clusters; and men reported nagging and irritating clusters.

CONCLUSION

The data suggest differences in CVD symptoms and clusters by sex. Symptoms in the two clusters were different; however, there was consistency in the factors associated with each cluster. Co-morbid conditions and sex differences in pain responses may play a part in symptom presentation. This study supports the need for increased sex-delineated clinical assessment and consideration of the potential differences between the sexes in the management of CVD symptoms.