Efficacy and safety of intranasal insulin on postoperative cognitive dysfunction in elderly patients after laparoscopic radical resection of colorectal cancer: a double-blind pilot study.

OBJECTIVE: To evaluate the efficacy and safety of intranasal insulin on postoperative cognitive dysfunction (POCD) in elderly patients after laparoscopic radical resection of colorectal cancer. METHODS: Older patients scheduled for laparoscopic radical resection of colorectal cancer at Beijing Luhe Hospital, Capital Medical University, between August 2023 and November 2023, were enrolled in this double-blind pilot study. Patients were randomized to the control and insulin groups at a 1:1 ratio. The primary outcome was the rate of POCD at postoperative 7 days. RESULTS: A total of 61 patients (30 in the insulin group) were analyzed. The insulin group had a significantly lower POCD rate compared with the control group at postoperative day 7 [4(13.3%) vs. 12 (38.7%), p = 0.024]. The serum levels of IL-6, TNF-α and S100β at T(2-5) in the insulin group were significantly lower than those of the control group (IL-6: mean difference at T(2), -4.14, p = 0.036; T(3), -3.84, p = 0.039; T(4), -3.37, p = 0.013; T(5), -2.57, p = 0.042; TNF-α: mean difference at T(2), -3.19, p = 0.002; T(3), -2.35, p = 0.028; T(4), -2.30, p = 0.019; T(5), -1.96, p = 0.0181; S100β: mean difference at T(2), -8.30, p = 0.019; T(3), -23.95, p = 0.020; T(4), -20.01, p = 0.023; T(5), -17.67, p = 0.010). No insulin allergic reactions, nasal irritation, or hypoglycemic reactions were observed in either of the groups. CONCLUSION: Intranasal insulin may decrease the risk of POCD and inhibit the elevated serum IL-6, TNF-α, and S100β levels in elderly patients after laparoscopic radical resection of colorectal cancer, which proves that intranasal insulin may be a promising therapeutic option for POCD. CLINICAL TRIAL REGISTRATION: Identifier, ChiCTR2300074423.