Skeletal muscle mass and risk of advanced adenoma in surveillance colonoscopy

Background and Aim: Sarcopenia has been suggested to be associated with chronic inflammation and insulin resistance. This study aimed to evaluate whether low muscle mass is associated with the incidence and recurrence of advanced colorectal adenoma. Methods: We conducted a cohort study including 14 701 participants who underwent first-time screening colonoscopy between 2003 and 2012 and follow-up colonoscopy until 2017. Skeletal muscle mass was measured using a bioelectrical impedance analyzer and divided by body weight to calculate the skeletal muscle mass index (SMI). Results: During a median 47 (interquartile range, 35–58) months of follow-up, overall and advanced adenoma developed in 2988 (20.3%) and 207 (1.41%) participants, respectively. In multivariate analysis using models adjusted for baseline adenoma risk, lifestyle factors, markers for insulin resistance and chronic inflammation, and metabolic syndrome, decreasing SMI quartiles were associated with increased risk of occurrence of advanced adenoma and overall adenoma. The adjusted hazard ratios (95% confidence intervals) comparing SMI quartiles 3, 2, and 1 to quartile 4 were 1.57 (1.03–2.41), 1.22 (0.78–1.92), and 1.77 (1.13–2.76), respectively, for advanced adenoma (P for trend = 0.049) and 1.05 (0.95–1.17), 1.09 (0.98–1.21), and 1.26 (1.13–1.41), respectively, for overall adenoma (P for trend < 0.001). Conclusions: In this large cohort with long-term colonoscopy follow-up, low relative muscle mass was associated with increased risk of occurrence of advanced adenoma and overall adenoma at follow-up colonoscopy, independent of metabolic and inflammatory markers. Timely and thorough surveillance colonoscopy may be emphasized in such populations.