Insulin resistance, central obesity, and risk of colorectal adenomas

Authors

  • Ana Patricia Ortiz MPH, PhD,

    1. Cancer Control and Population Sciences Program, University of Puerto Rico Comprehensive Cancer Center, San Juan, Puerto Rico
    2. Department of Biostatistics and Epidemiology, Graduate School of Public Health, University of Puerto Rico, San Juan, Puerto Rico
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  • Cheryl L. Thompson PhD,

    1. Department of Family Medicine, Case Center for Transdisciplinary Research on Energetics and Cancer, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio
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  • Amitabh Chak MD,

    1. Case Center for Transdisciplinary Research on Energetics and Cancer, Case Comprehensive Cancer Center, Cleveland, Ohio
    2. Department of Gastroenterology, University Hospitals Case Medical Center, Cleveland, Ohio
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  • Nathan A. Berger MD,

    1. Department of Medicine, Case Center for Transdisciplinary Research on Energetics and Cancer, Case Comprehensive Cancer Center, Cleveland, Ohio.
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  • Li Li MD, PhD

    Corresponding author
    1. Department of Family Medicine, Case Center for Transdisciplinary Research on Energetics and Cancer, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio
    • Department of Family Medicine – Research Division, Case Western Reserve University, 11000 Cedar Avenue, Suite #402, Cleveland, OH 44106-7136
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    • Fax: (216) 368-4348


Abstract

BACKGROUND:

Increasing evidence supports insulin resistance (IR) as the underpinning of the obesity-colorectal neoplasia link. The homeostasis model assessment-IR (HOMA-IR) is a widely accepted index of evolving hyperinsulinemia and early IR. Studies of the relation between HOMA-IR and colorectal adenomas are limited. Therefore, the authors sought to determine the associations of HOMA-IR and central obesity (waist to hip ratio [WHR]) with risk of colorectal adenomas in a screening colonoscopy-based study.

METHODS:

The authors collected lifestyle information and fasting blood samples from 1222 participants (320 incident adenoma cases and 902 without adenomas) before their screening colonoscopies. Unconditional logistic regression models were used to assess risk associations.

RESULTS:

In multivariate analysis of participants (n = 1093) reporting no antidiabetic medication use, those in the top quartile of WHR were twice as likely (odds ratio [OR], 2.18; 95% confidence interval [CI], 1.33-3.57; P-trend = .003) and those in the top quartile of HOMA-IR were 63% more likely (OR, 1.63; 95% CI, 1.09-2.44; P-trend = .01) to have adenomas compared with those in the bottom quartiles. Stratified analysis revealed a statistically significant interaction between HOMA-IR and sex (P-interaction = .04), with the association largely limited to men; compared with those in the bottom tertile, men in the top tertile of HOMA-IR were twice more likely to have adenomas (OR, 2.11; 95% CI, 1.18-3.78; P-trend = .01).

CONCLUSIONS:

The results support central obesity and insulin resistance, particularly in men, as important risk factors for the development of early colorectal neoplasia. Cancer 2012;. © 2011 American Cancer Society.

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