Nonalcoholic Steatohepatitis Is Associated With a Higher Risk of Advanced Colorectal Neoplasm

Yuri Cho; Soo-Kyung Lim; Sae Kyung Joo; Dong-Hyong Jeong; Jung Ho Kim; Jeong Mo Bae; Jeong Hwan Park; Mee Soo Chang; Dong Hyeon Lee; Yong Jin Jung; Byeong Gwan Kim; Donghee Kim; Kook Lae Lee; Won Kim


Liver International. 2019;39(9):1722-1731. 

In This Article

Materials and Methods

Patients and Clinical Assessment

We prospectively recruited consecutive 750 patients with clinically suspected NAFLD from the ongoing Boramae NAFLD registry (NCT 02206841) between January 2013 and November 2018. All patients underwent liver biopsy to evaluate the presence of NAFLD, histologically. The inclusion criteria for this study were as follows: (a) ≥18 years old, (b) bright echogenic liver on ultrasound scanning (liver hyperechogenicity compared to kidney and posterior attenuation),[14] and (c) unexplained high alanine aminotransferase (ALT) levels above the upper normal limit for men (30 IU/L) and women (19 IU/L) within the prior 6 months.[15] The following exclusion criteria were used: (i) hepatitis B or C virus infection, (ii) autoimmune hepatitis or primary biliary cholangitis, (iii) drug-induced liver injury or steatosis, (iv) Wilson disease or hemochromatosis, (v) excessive alcohol consumption (males >30 g/day, females >20 g/day),[16] (vi) diagnosis of malignancy within the prior year, (vii) family history of CRC in first-degree relatives, (viii) having an inherited syndrome (eg Lynch syndrome, Peutz-Jeghers syndrome, MYH-associated polyposis or familial adenomatous polyposis), (ix) past medical history of colorectal neoplasm, (x) inflammatory bowel disease, (xi) bowel symptoms (eg hematochezia, melena, or bowel habit change), (xii) patients who underwent polypectomy within the last 5 years, and (xiii) patients who declined to undergo colonoscopy. Among the eligible study participants, those with at least two of the following risk factors underwent liver biopsy: diabetes mellitus, central obesity (waist circumference ≥90 cm for men or ≥80 cm for women), a high level of triglycerides (TG) (≥150 mg/dL), a low level of high-density lipoprotein (HDL)-cholesterol (<40 mg/dL for men or <50 mg/dL for women), the presence of hypertension, insulin resistance, and clinically suspected NASH or fibrosis.[17]

A well-trained examiner recorded anthropometric measurements according to a consistent protocol. Body mass index was calculated as weight (kg) divided by height squared (m2). Waist circumference was measured at the end of normal expiration, measuring at a midway between the lower rib margin and the iliac crest; the tape measure was placed completely around the waist in the horizontal position. Venous blood samples were drawn at the time of biopsy after a 12 hours overnight fasting, and plasma was separated immediately via centrifugation. The plasma glucose and lipid concentrations were measured enzymatically using the Hitachi Automatic Analyzer B2400 (Hitachi, Tokyo, Japan). Fasting insulin levels were measured using immunoradiometric assays (DIA source ImmunoAssays, Nivelles, Belgium). Insulin resistance was evaluated using the homeostasis model assessment of insulin resistance (HOMA-IR), as described previously.[18]

Diabetes mellitus was defined as fasting plasma glucose (FPG) levels ≥126 mg/dL, HbA1c levels ≥6.5% and/or treatment with anti-diabetic medication(s) at the time of the survey. Hypertension was defined as systolic blood pressure (SBP) ≥140 mmHg, diastolic blood pressure (DBP) ≥90 mmHg and/or the current use of anti-hypertensive medication(s). Smokers were defined as those who had smoked at least one cigarette per day during the previous year. Metabolic syndrome was defined as having at least three of the following (a) waist circumference ≥90 cm (males) or 80 cm (females) in Asia, (b) TG ≥ 150 mg/dL, (c) HDL-cholesterol < 40 mg/dL (males) or 50 mg/dL (females), (d) SBP ≥ 130 mmHg or DBP ≥ 85 mmHg, and (e) FPG ≥ 110 mg/dL.[19]

This study was conducted in accordance with the provisions of the Declaration of Helsinki for the participation of human subjects in research and approved by the Institutional Review Board of Seoul National University Boramae Medical Center (IRB No. 30-2019-37). All subjects in the study cohort provided written informed consent.

Colonoscopy Examination

Among a total of 750 patients in the Boramae NAFLD registry, 476 patients (63.5%) underwent colonoscopy from January 2013 to November 2018 using a CF-H260 colonoscope (Olympus, Tokyo, Japan) by board-certified gastroenterologists who had performed more than 500 colonoscopies. All colonoscopies were performed for screening CRC or colorectal adenoma. For adequate bowel preparation, subjects were given 4 L of polyethylene glycol lavage solution. During colonoscopy, either intravenous midazolam and pethidine or pethidine alone was administered by the gastroenterologists according to participants' medical conditions. Colonoscope reaching the cecum, documented by a picture of ileocecal valve, was defined as a complete colonoscopic examination. All polypoid lesions were biopsied or removed and histologically assessed by experienced pathologists. All polypoid lesions were classified by number, size, and histological characteristics (tubular, tubule-villous, or villous adenoma; hyperplastic polyp; or sessile serrated or traditional serrated adenoma). Hyperplastic polyps, inflammatory polyps, or lipomas were not considered as colorectal adenomas. The grade of dysplasia was classified as low or high. The location and size of all detected colorectal lesions were documented (measured by biopsy forceps that expanded to ≥6 mm) by photographs. Advanced colorectal neoplasm was defined as an adenomatous polyp 10 mm or larger in diameter and/or with a feature of villous adenoma, and/or high-grade dysplasia or adenocarcinoma.[20]

Liver Histology

Percutaneous liver biopsy specimen, obtained using 16-gauge disposable needles, were fixed in 4% formalin, and embedded in paraffin. Adequate specimens, at least 20 mm in length and 3 mm thick, were stained with hematoxylin-eosin and Massson's trichrome. One experienced liver pathologist (JHK) assessed and reviewed all liver biopsy specimens.[21] Subjects with biopsies in which at least 5% of hepatocytes displayed macrovesicular steatosis, were diagnosed with NAFLD. Hepatic injury consisting of macrovesicular steatosis, lobular inflammation, and hepatocellular ballooning was defined as NASH according to Brunt et al's criteria.[22,23] Fibrosis was staged from 0 to 4, according to criteria of Kleiner et al.[24] Significant fibrosis was defined as ≥F2. Included patients had an NAFLD activity score (NAS) ranging from 0 to 8.

Statistical Analysis

Differences between groups were evaluated using the independent t test and analysis of variance (ANOVA). Categorical variables were compared using the chi-square test and Fisher's exact test. To investigate the associations of NAFLD and other risk factors with advanced colorectal neoplasm, binary logistic regression analysis was performed. Multivariate logistic regressions analysis, adjusted for age and sex, included clinically significant cofounders and variables selected from the results of the binary analysis: variable having a P < 0.10. If there was a positive co-linearity between the covariates, the most objective and easily applicable variable was selected as a representative variable for multivariate analysis. Each odds ratio (OR) is presented together with its 95% confidence interval (CI). All statistical analyses were conducted using STATA 13.0 (StataCorp, College Station, TX) and SPSS Statistics software version 23.0 (IBM Corporation, Armonk, NY). Significance was defined as P < 0.05.