Static and dynamic quantitative sensory testing in chronic pancreatitis: Relation of pain sensitization to...

The etiology of pain in chronic pancreatitis is multi-factorial and includes altered central pain processing. Pancreatic Quantitative Sensory Testing (P-QST) indirectly assesses pain sensitization, yet its clinical significance in relation to psychological comorbidities and quality of life (QoL) remains unclear in Indian populations. The primary objective was to apply an unbiased, data-driven clustering approach using P-QST parameters to stratify patients into centrally sensitized and non-sensitized phenotypes and evaluate their associations with demographic, clinical and patient-reported outcome variables.

This cross-sectional study enrolled Indian patients with painful chronic pancreatitis between June 2021 and October 2023. We assessed static (pressure pain thresholds and cold pressor endurance) and dynamic (temporal summation and conditioned pain modulation) P-QST parameters to characterize pain processing. Psychological comorbidities, pain catastrophizing and quality of life were measured using validated questionnaires. We compared demographic, clinical and patient-reported outcome variables across pain phenotypes identified from K-median clustering of P-QST parameters.

We enrolled 264 patients (mean [SD] age- 35.6 [11.0] years, male [%]- 177 [67], idiopathic etiology [%]- 188 [71]). Cluster analysis revealed two distinct pain phenotypes: sensitized (n = 100) and non-sensitized (n = 164). Sensitized patients had lower pressure detection thresholds (2020 vs. 2691 kPa; p < 0.001), shorter cold pressor endurance time (40 s vs. 70 s; p < 0.001) and greater temporal summation (p < 0.001). Demographics and clinical characteristics were comparable between groups, but sensitized patients reported poorer physical (p = 0.037) and social functioning (p = 0.027) and greater fatigue (p = 0.012). No differences were observed for psychological comorbidities.

Using an unbiased, data-driven approach, we identified distinct P-QST pain phenotypes in chronic pancreatitis patients, independent of psychological comorbidities, supporting its potential as an unbiased pain assessment tool.