Impact of pain sensitization phenotypes on quality of life among adults with sickle cell disease

Abstract Introduction: Recent research has shown that sensitization contributes to chronic pain phenotypes in adults with sickle cell disease (SCD). Yet, no study has been published on the impact of sensitization on quality of life (QoL) in SCD. We compared differences in their QoL by sensitization classification (sensitization vs normal sensation) among outpatient adults with SCD. Method: In a comparative study, 180 adults with SCD pain (mean age 36.6 ± 11.7 years; 62% female; 71% SS genotype, 29% other SCD variants; 98% African American) underwent quantitative sensory testing (QST) with the Medoc TSA-II Neurosensory Analyzer and von Frey filaments. QST was conducted at three body sites (2 painful, one non-painful as a reference). Participants were classified as sensitized if positive to either Aβ, Aδ, or C-fiber stimulation with allodynia/hyperalgesia responses across three sites, and normal sensation when sensate and negative for allodynia/hyperalgesia. Participants also completed the 30-item Adult Sickle Cell Quality of Life Measurement Information System (ASCQ-Me). The ASCQ-Me has seven domains, including (fixed form: pain episodes frequency and pain episodes severity domains), and (short form: pain impact, emotional impact, sleep impact, stiffness impact, and social functioning impact), with a population mean normed at 50 ± 10. For pain episodes, the scores are reversed, with higher scores indicating worse health. In contrast to other domains, higher scores indicate good health or less impact. Independent t-tests were conducted to compare the ASCQ-Me domains by sensitization groups using the SAS statistical software package. Results: We report ASCQ-Me scores by sensitization groups, including the mean ± SD, t-statistics, and their degrees of freedom, and p-values. Of the 180 participants with QST data, all were sensate, 56 (31%) had evidence of sensitization, and 124 (69%) had normal sensation. QoL scores were significantly lower among the sensitized group compared to normal sensation group on pain impact (M = 45 ± 7.9 vs M = 49 ± 7.7, t(178) = -2.88, p<.01), emotional impact (M = 46 ± 8.5 vs 50 ± 7.4, t(176) = -3.42, p<.001), sleep impact (M = 48 ± 5.7 vs M = 51 ± 6.2, t(177) = -2.62, p<.01), stiffness impact (M = 46 ± 8.8 vs 50 ± 8.4, t(177) = -3.00, p<.01), and social functioning impact (M = 47 ± 7.9 vs 51±7.8, t(177) = -2.65, p<.01). Differences for pain frequency (M = 49 ± 5.4 vs 48 ± 5.6, t (178) = 1.31, p>0.05) and pain severity episodes (M = 51± 9.7 vs 48 ± 10, t(178) = 1.70, p>0.05) were not statistically significant. Conclusion: Findings revealed a significant impact of sensitization pain phenotypes on QoL, with lower scores observed among SCD adults who were sensitized compared to those with normal sensation. Pain frequency and severity did not significantly differentiate the two pain phenotypes. Interventions should be individualized and tailored toward optimizing QoL in this population.