Circulating 25-Hydroxyvitamin-D and Risk of Colorectal Adenomas and Hyperplastic Polyps

Abstract

Colorectal adenomas are clear precursors of cancer; hyperplastic polyps may also have malignant potential. An inverse association between circulating vitamin D metabolites and adenoma risk has been reported, but less is known about vitamin D and hyperplastic polyps. We conducted a case-control study of adenomas and hyperplastic polyps among 459 members of an integrated health plan evaluated via colonoscopy. Questionnaires provided information on colorectal polyp risk factors, and plasma samples were assayed for 25-hydroxyvitamin-D [25(OH)D]. Polytomous regression was used to estimate odds ratios for adenomas (n = 149) and hyperplastic polyps (n = 85) compared to polyp-free controls (n = 225) by tertile of 25(OH)D. An inverse association between 25(OH)D and adenomas was suggested after adjustment for potential confounding factors [comparing upper to lower tertiles, OR (95%CI): 0.71 (0.38–1.30)]. After restriction of the analyses to study participants with no history of polyps, this OR estimate was reduced further [adjusted OR (95%CI): 0.52 (0.23–1.20)]. In comparison, no inverse association between hyperplastic polyps and 25(OH)D was observed among the full study participants [adjusted OR (95%CI): 1.17 (0.55–2.51)] or among those without prior polyps [adjusted OR (95%CI): 1.42 (0.55–3.65)]. Our study suggests that the established inverse association between circulating 25(OH)D and adenoma may not apply to hyperplastic polyps.

ACKNOWLEDGMENTS

This study was supported by a National Cancer Institute grant (P01 CA74184), training funds to ANBH (T32 CA09168-32), and additional research funding and support for SVA from a National Institute of Health, National Cancer Institute Cancer Prevention Training Grant (R25 CA094880). The authors thank Thomas Laha and Andrew Hoofnagle at the University of Washington Clinical Nutrition Research Unit (Seattle, WA) for performing the 25(OH)D assays. The preliminary results of this study were presented at the American Society of Preventive Oncology meeting, March 2010 (Bethesda, MD). The authors have no competing interests.

Notes

*Use of multivitamins, calcium, or vitamin D supplements at least once per week.