Case Control Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Aug 7, 2015; 21(29): 8868-8877
Published online Aug 7, 2015. doi: 10.3748/wjg.v21.i29.8868
Circulating levels of vitamin D and colorectal adenoma: A case-control study and a meta-analysis
Yoon Ji Choi, Young Ha Kim, Chang Ho Cho, Sung Hi Kim, Jung Eun Lee
Yoon Ji Choi, Young Ha Kim, Jung Eun Lee, Department of Food and Nutrition, Sookmyung Women’s University, Seoul 140-742, South Korea
Chang Ho Cho, Department of Pathology, Daegu Catholic University Medical Center, Daegu 427-724, South Korea
Sung Hi Kim, Department of Family Medicine, Daegu Catholic University Medical Center, Daegu 427-724, South Korea
Author contributions: Choi YJ and Kim YH performed the statistical analysis; Choi YJ drafted the manuscript; Cho CH and Kim SH collected data and reviewed the manuscript; Lee JE designed the study and drafted the manuscript.
Supported by Grants from Basic Science Research Program through the National Research Foundation of Korea, which is funded by the Korean Government, No. NRF-2011-0011028; and the Sookmyung Women’s University Research Grants, No. 1-1503-0168.
Conflict-of-interest statement: There is no conflict of interest to declare.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Jung Eun Lee, ScD, Department of Food and Nutrition, Sookmyung Women’s University, Cheongpa-ro 47-gil 100, Yongsan-gu, Seoul 140-742, South Korea. junglee@sm.ac.kr
Telephone: +82-2-2077-7560 Fax: +82-2-710-9479
Received: February 28, 2015
Peer-review started: March 2, 2015
First decision: April 13, 2015
Revised: May 19, 2015
Accepted: June 10, 2015
Article in press: June 10, 2015
Published online: August 7, 2015
Processing time: 160 Days and 16.7 Hours
Abstract

AIM: To examine the association between circulating 25-hydroxyvitamin D [25(OH)D] levels and colorectal adenoma in a case-control study and a meta-analysis.

METHODS: We conducted a matched case-control study (112 cases and 112 matched controls) and combined 15 studies, including our study, in a meta-analysis. The study-specific odds ratios (ORs) and 95% confidence intervals (CIs) were pooled using a random-effects model. In total, 5454 colorectal adenomas and 6656 controls were included in the meta-analysis.

RESULTS: In a meta-analysis including 14 previous studies and our study, we observed a significant inverse association between circulating 25(OH)D levels and colorectal adenoma (OR = 0.68; 95%CI: 0.54-0.82) when comparing the highest category with the lowest category. Stratification by adenoma location (proximal or distal adenoma) showed similar estimates. When we stratified by study region, the ORs (95%CIs) were 0.70 (0.52-0.88) in the US and 0.66 (0.34-0.97) in Asia.

CONCLUSION: These data suggest an inverse association between circulating 25(OH)D levels and colorectal adenoma in both Western and Asian populations.

Keywords: 25-hydroxyvitamin D levels; Colorectal adenoma; Cancer prevention

Core tip: Growing evidence from epidemiologic studies suggests a preventive effect of vitamin D against colorectal cancer. Colorectal adenoma is considered to be a precursor lesion of colorectal cancer. We conducted a case-control study in Korean adults and also calculated a summary estimate through a meta-analysis to examine the association between circulating 25-hydroxyvitamin D[25(OH)D] levels and colorectal adenoma. We found an inverse association between circulating 25(OH)D levels and colorectal adenoma, and this association was consistent for Asian populations.