Association between obesity, gender and preoperative inflammatory markers with postsurgical pain in live kidney donors.

Background: Pain perception has unresolved controversies. The live kidney donor is a model of a healthy subject without a previous painful disease. Our aim is to investigate the association among preoperative obesity, gender, and inflammatory marker levels with postsurgical pain intensity and analgesic consumption.

Methods: We included 70 kidney donors classified as normal weight, overweight, or obese. We measured percentage of adiposity, leptin, adiponectin, IL-6, IL1β, TNFα, malondialdehyde, erythrocyte sedimentation rate, white blood cells, serum glucose, creatinine, creatinine clearance, and lipid profile 1 week prior to surgery. Visual analogue scale (VAS) scores at 0, 12, 24, and 48 h postsurgery were evaluated. Data were analyzed by means, ANOVA and/or Kruskal-Wallis test. Association among VAS score, ropivacaine consumption, and preoperative cytokine levels was carried out using the Pearson correlation test; p value ≤ 0.05 was considered significant.

Results: Normal weight and overweight patients showed a positive correlation of VAS with analgesic requirements. In obese donors there was no correlation. Leptin levels were positively correlated with body mass index (BMI) and adiposity (rP 0.574, and rP 0.764). IL-6 serum concentration was higher in males than in females in all BMI groups. Adiposity percentage and BMI exhibited an inverse correlation with VAS scores at 48 h (rP -0.442 and rP -0.397, respectively), and IL-1β was correlated with the VAS score at 8 h (r = 0.417).

Conclusions: We observed no statistical differences in the proinflammatory cytokine preoperative serum levels and other inflammatory markers among groups. In our study, obese patients used higher doses of ropivacaine than overweight or normal weight patients.