Is preoperative hypocholesterolemia a risk factor for severe postoperative pain? Analysis of 1,944 patients after laparoscopic colorectal cancer surgery

PURPOSE: This study aimed to identify the effect of preoperative serum total cholesterol on postoperative pain outcome in patients who had undergone laparoscopic colorectal cancer surgery. METHODS: We retrospectively reviewed the medical records of patients diagnosed with colorectal cancer who had undergone laparoscopic colorectal surgery from January 1, 2011, to June 30, 2017, to identify the relationship of total cholesterol levels within a month prior to surgery with the numeric rating scale (NRS) scores and total opioid consumption on postoperative days (PODs) 0–2. RESULTS: We included 1,944 patients. No significant correlations were observed between total cholesterol and the NRS (POD 0), NRS (POD 1), and oral morphine equivalents (PODs 0–2) (P>0.05). There was no significant difference between the low (<160 mg/dL), medium (160–199 mg/dL), and high (≥200 mg/dL) groups in NRS scores on PODs 0, 1, or 2 (P>0.05). Furthermore, there was no significant association in multivariate linear regression analysis for postoperative opioid consumption according to preoperative serum total cholesterol level (coefficient 0.08, 95% CI −0.01 to 0.18, P=0.81). CONCLUSION: This study showed that there was no meaningful association between preoperative total cholesterol level and postoperative pain outcome after laparoscopic colorectal cancer surgery.