Physical Stress from Colonoscopy and Polypectomy in Elderly Individuals: Evaluation Using Damage Biomarkers in Blood

Colonoscopy is routinely performed worldwide, but it is still a physically stressful screening method for colorectal cancer, particularly in elderly individuals. No previous study has evaluated physical stress from colonoscopy itself and polypectomy using blood-derived biomarkers. This study aimed to evaluate physical stress from colonoscopy and polypectomy in elderly individuals using white blood cell counts (WBCs) and C-reactive protein (CRP) levels, which are widely used blood-based biomarkers that respond quickly to tissue damage. In this single-center, retrospective observational study, 109 consecutive patients, aged ≥ 80 years, were enrolled. In all patients, WBCs and CRP levels were measured before and half-a-day after colonoscopy. The changes were subsequently compared. Patients were divided into two groups: those with polypectomy (P+) and those without polypectomy (P-). The changes in WBCs and CRP levels were determined and compared between the two groups. In the P + group, correlations between the number of resected polyps and changes in WBCs and CRP levels were also evaluated. Of the 109 patients, there were 48 men and 61 women with a mean age of 83.9 ± 3.1 years (range, 80-91 years); 58 patients received polypectomy. In all patients, the mean WBC after colonoscopy showed no significant change from that before colonoscopy (before: 5400/μL, after: 5200/μL, P = 0.092), and the mean CRP level showed a slight elevation after colonoscopy (before: 0.05 mg/dL, after: 0.08 mg/dL, P P = 0.002), but showed no significant difference in the P+ group (5400/μL, 5400/μL, P = 0.48). Conversely, the mean CRP level increased very slightly in both the P- and P+ groups (from 0.06 mg/dL to 0.07 mg/dL, P = 0.003; from 0.04 mg/dL to 0.08 mg/dL, P < 0.001, respectively), but it was not significantly different between the groups. The elevation of both WBCs and CRP levels showed only minor correlations with the number of resected polyps. In conclusion, colonoscopy can be well tolerated even by elderly individuals because physical stress from colonoscopy, with respect to WBCs and CRP levels, was minimal even if polypectomy was performed.