Interaction of Factors Related to the Metabolic Syndrome and Vitamin D on Risk of Prostate Cancer
- Pentti Tuohimaa1,
- Leena Tenkanen3,
- Heimo Syvälä1,
- Sonja Lumme3,
- Timo Hakulinen4,
- Joakim Dillner5 and
- Matti Hakama2
- 1Medical School, University of Tampere and Department of Clinical Chemistry, Tampere University Hospital; 2School of Public Health, University of Tampere, Tampere, Finland; 3Helsinki Heart Study; 4Finnish Cancer Registry, Helsinki, Finland; and 5Department of Medical Microbiology, MAS University Hospital, Malmö, Sweden
- Requests for reprints:
Pentti Tuohimaa, Medical School, University of Tampere, FIN-33014 Tampere, Finland. Phone: 358-3-35516726; Fax: 358-3-35516170. E-mail: Pentti.Tuohimaa{at}uta.fi
Abstract
Background: Factors related to the metabolic syndrome and low levels of vitamin D have been implicated as risk factors for prostate cancer. Insofar, no studies have assessed their joint effects on prostate cancer risk.
Methods: We studied (a) the associations of vitamin D with the metabolic syndrome factors body mass index, systolic and diastolic blood pressure, and high-density lipoprotein cholesterol (HDL-C) and (b) the prostate cancer risk associated with these factors and especially their joint effects with vitamin D on risk of prostate cancer. We did a longitudinal nested case-control study on 132 prostate cancer cases and 456 matched controls from a cohort of 18,939 Finnish middle-aged men from the Helsinki Heart Study. The odds ratios (OR) of prostate cancer were assessed via conditional logistic regression analysis.
Results: Apart from HDL-C, there was no linear association between the metabolic syndrome factors and vitamin D levels. In univariate analysis, men in the highest quartiles of body mass index (>28 kg/m2) and systolic blood pressure (>150 mmHg) showed a modest increase in risks of prostate cancer, with ORs of 1.37 (P = 0.16) and 1.53 (P = 0.05) when compared with the three lower quartiles, but low HDL-C entailed no prostate cancer risk. However, with all three factors present, the OR was 3.36 (P = 0.02), and jointly with low vitamin D (≤40 nmol/L), the OR was 8.03 (P = 0.005) compared with those with no metabolic syndrome factors and intermediate levels of vitamin D. There was an interaction between vitamin D and the metabolic syndrome factors so that a clustering of these factors entailed high risk of prostate cancer but only if vitamin D level was low (≤40 nmol/L). If it was at intermediate levels, the metabolic syndrome factors entailed no prostate cancer risk.
Conclusions: We conclude that the prostate cancer risk associated with factors related to the metabolic syndrome is strongly conditioned by levels of vitamin D. (Cancer Epidemiol Biomarkers Prev 2007;16(2):302–7)
Footnotes
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Grant support: Finnish Cancer Foundation, Academy of Finland, and University Hospital of Tampere.
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The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
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Note: P. Tuohimaa and L. Tenkanen contributed equally to this work.
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This is study number xx from the Nordic Biological Specimen Bank Working Group on Cancer Causes and Control.
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- Accepted December 1, 2006.
- Received September 14, 2006.
- Revision received November 24, 2006.
