title: Urinary 1-methylhistidine and 3-methylhistidine, meat intake, and colorectal adenoma risk.
abstract: Self-reported red and processed meat intake has been positively associated with colorectal adenoma and cancer; however, measurement error in self-reported data can attenuate risk estimates, increasing the need for improved exposure assessment methods to better understand this association. A controlled feeding study revealed that urinary 1-methylhistidine and 3-methylhistidine levels were dose-dependently associated with meat intake; our aim was to examine these analytes in relation to colorectal adenoma. Individuals undergoing routine cancer screening by sigmoidoscopy or colonoscopy were recruited for a colorectal adenoma case-control study; participants completed a food frequency questionnaire and a meat questionnaire, and donated urine. Urinary 1-methylhistidine and 3-methylhistidine levels were measured in 131 case-control pairs (age, sex, and smoking matched); odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by logistic regression. Although the mean self-reported red meat intake was higher in cases (59 g/day) than in controls (48 g/day), the mean urinary 1-methylhistidine and 3-methylhistidine levels did not differ by case status (P=0.72). Neither urinary 1-methylhistidine nor urinary 3-methylhistidine was associated with colorectal adenoma (OR continuous=0.90, 95% CI: 0.53-1.54; OR continuous=0.90, 95% CI: 0.69-1.17, respectively). A variable combining self-reported red meat intake with urinary 1-methylhistidine and 3-methylhistidine levels was not associated with colorectal adenoma. Analyzing urine samples from multiple days from 17 individuals revealed intraclass correlations of 0.52 and 0.49 for 1-methylhistidine and 3-methylhistidine, respectively; this variability could result in attenuated risks. Urinary 1-methylhistidine and 3-methylhistidine levels, measured in one sample, were not associated with colorectal adenoma.
authors.affiliation: Department of Health and Human Services, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, Maryland, USA.
authors.forename: Amanda J
authors.initials: AJ
authors.lastname: Cross
authors.forename: Jacqueline M
authors.initials: JM
authors.lastname: Major
authors.forename: Nathaniel
authors.initials: N
authors.lastname: Rothman
authors.forename: Rashmi
authors.initials: R
authors.lastname: Sinha
mesh_terms: D000236:Adenoma / Q000175:diagnosis* / Q000209:etiology / Q000652:urine; D000293:Adolescent; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000652:urine*; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000209:etiology / Q000652:urine; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008460:Meat / Q000009:adverse effects*; D008762:Methylhistidines / Q000652:urine*; D008875:Middle Aged; D016017:Odds Ratio; D011379:Prognosis; D012307:Risk Factors; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D008762:Methylhistidines; C028120:1-methylhistidine; C028118:3-methylhistidine