1. 2020;23;E695-E702Resistin Gene Polymorphism Is an Influencing Factor of Postoperative Pain for Chinese Patients
   Observational Study
   Han Xie, MD, Qingqing Fan, MD, Zhengliang Ma, PhD, Zhengxiang Chen, MD, Qing Shu, PhD, Danying Li, PhD, and Weihong Ge, MD.

BACKGROUND: Gene polymorphism is an important factor affecting the efficacy and dosage of opioids. A recent study showed RETN rs3745367 was associated with postoperative pain intensity. OPRM1 gene was confirmed to affect the postoperative analgesic consumption of morphine and other opioids.

OBJECTIVE: In this study, we investigated the association between single nucleotide polymorphisms (SNPs) in the RETN, OPRM1 gene and postoperative pain intensity, analgesics consumption, and ADR. The haplotype analysis focus on OPRM1 was also implemented.

STUDY DESIGN: This was a prospective, observational study.

SETTING: Patients undergoing spinal fusion and correction operation were recruited. Genotypes of rs3745367, rs1799971, rs2075572, and rs9322447 were tested. Pain assessment was performed to measure postoperative pain intensity, postoperative fentanyl and pethidine consumption was recorded to calculate analgesics consumption, and adverse reactions were recorded.

METHOD: We recruited 142 patients undergoing spinal correction and fusion. Genotyping was performed by using a real-time polymerase chain reactions (PCRs) system and validated with allelic discrimination assays. The pain was assessed using a numerical rating scale (NRS). Statistical analyses were performed using SPSS software. LD test and the construction and analysis of haplotype were using Haploview software.

RESULTS: Rs3745367 demonstrated a significant association with postoperative average pain intensity in 24h (P = 0.015) and 48h (P = 0.001) after surgery. Rs2075572 and rs9322447 influenced postoperative maximal pain intensity in 48h after surgery (P = 0.042, 0.033, respectively). No correlation was found between OPRM1 SNPs and analgesics consumption and adverse reaction. According to the results of this study, a strong LD was observed between rs1799971 and rs9322447 (Block 1, LD parameters: D’ = 0.82, r2 = 0.14), rs2075572 and rs9322447 (Block 2, LD parameters: D’ = 0.92, r2 = 0.51).

LIMITATIONS: The association between rs3745367 with serum resistin levels was not investigated in this research, serum resistin levels of the incision part should be investigated in future studies.

Conclusion: RETN rs3745367 was associated with postoperative average pain intensity, OPRM1 rs2075572 and rs9322447 may influence postoperative maximal pain intensity.

KEY WORDS: Postoperative pain, RETN, OPRM1, gene polymorphism, haplotype, opioid, morphine