Table 2.

Retrospective studies examining the risk of colorectal adenomas and cancer in patients with NAFLD.

Author, Year of Publication	Study Population	Country	Diagnosis of NAFLD	Results
Wong et al., 2011 [23]	199 patients with NAFLD and 181 healthy controls	China	Magnetic resonance spectroscopy (n = 64) and liver biopsy (n = 135)	NASH was independently associated with colorectal adenomas (adjusted OR, 4.89; 95% CI, 2.04–11.70) and advanced colorectal neoplasms (adjusted OR, 5.34; 95% CI, 1.92–14.84).
Stadlmayr et al., 2011 [24]	1211 subjects who underwent screening colonoscopy	Austria	Ultrasonography (other chronic liver diseases were excluded)	The prevalence of colorectal lesions was 34% in the NAFLD group and 21.7% in the control group (p < 0.001). NASH was independently associated with colorectal adenomas (adjusted OR, 1.47; 95% CI, 1.08–2.00).
Touzin et al., 2011 [25]	94 patients with biopsy-proven NAFLD and 139 patients without NAFLD	United States	Histological	No significant difference in the prevalence of colonic adenomas (24.4% in NAFLD patients compared with 25.1% in non-NAFLD patients) was seen. NAFLD patients had significantly greater numbers of colonic adenomas than non-NAFLD patients (p = 0.016).
Lee et al., 2012 [26]	5517 women (831 patients with NAFLD) who underwent health check-up	Korea	Ultrasonography	NAFLD was independently associated with colorectal adenomatous polyps (adjusted OR, 1.94; 95% CI, 1.11–3.40) and colorectal cancer (adjusted OR, 3.08; 95% CI, 1.02–9.34).
Huang et al., 2013 [27]	1522 health-check individuals who underwent two consecutive colonoscopies (no adenomas were detected at first colonoscopy)	Taiwan	Ultrasonography	NAFLD was an independent risk factor (OR, 1.45; 95% CI, 1.07–1.98) for adenoma formation after a negative baseline colonoscopy.
Ahn et al., 2017 [28]	26,540 subjects who underwent a first-time colonoscopy as part of a health check-up program	Korea	Ultrasonography	NAFLD was independently associated with colorectal neoplasia (adjusted OR, 1.10; 95% CI, 1.03–1.17) and advanced colorectal neoplasia (adjusted OR, 1.21; 95% CI, 0.99–1.47).
Blackett et al., 2020 [29]	123 patients with biopsy-proven NAFLD and controls without liver disease matched by age, sex, and endoscopist	United States	Histological	Patients with biopsy-proven NAFLD had a significantly higher colorectal adenoma prevalence independently of hyperlipidemia, diabetes, and obesity (OR, 1.74; 95% CI, 1.05–2.88).

NAFLD: Non-alcoholic fatty liver disease, NASH: Non-alcoholic steatohepatitis, OR: Odds ratio, CI: Confidence interval.