Reassessing the association between circulating Vitamin D and IGFBP-3: Observational and Mendelian randomization estimates from independent sources

Vanessa Y. Tan, Kalina M. Biernacka, Tom Dudding, Carolina Bonilla, Rebecca Gilbert, Robert C. Kaplan, Qi Qibin, Alexander Teumer, Richard M. Martin, Claire M. Perks, Nicholas J. Timpson, Jeff M.P. Holly

1 Scopus citations


Background: Circulating insulin-like growth factor binding protein 3 (IGFBP-3) has been associated with prostate cancer. Preclinical studies found that vitamin D regulates IGFBP-3 expression, although evidence from epidemiologic studies is conflicting. Methods: Mendelian randomization analyses (MR) were conducted to reassess associations between IGFBP-3 and prostate cancer risk and advanced prostate cancer using summary statistics from the PRACTICAL consortium (44,825 cases; 27,904 controls). Observational and MR analyses were conducted to assess the relationship between inactive vitamin D [25(OH)D] and IGFBP-3 using data from the ProtecT study (1,366 cases;1,071 controls) and summary statistics from the CHARGE consortium (n = 18,995). Results: The OR for prostate cancer per SD unit increase in circulating IGFBP-3 was 1.14 [95% confidence interval (CI), 1.02–1.28]. The OR for advanced prostate cancer per SD unit increase in IGFBP-3 was 1.22 (95% CI, 1.07–1.40). Observationally, a SD increase in 25(OH)D was associated with a 0.1SD (95% CI, 0.05–0.14) increase in IGFBP-3. MR analyses found little evidence for a causal relationship between circulating 25(OH)D and IGFBP-3 in the circulation. Conclusions: This study provided confirmatory evidence that IGFBP-3 is a risk factor for prostate cancer risk and progression. Observationally, there was evidence that 25(OH)D is associated with IGFBP-3, but MR analyses suggested that these findings were unlikely to be causal. Findings may be limited by the nature of instrumentation of 25(OH)D and IGFBP-3 and the utility of circulating measures. 25(OH)D appears unlikely to be causally related to IGFBP-3 in the circulation, however, our findings do not preclude causal associations at the tissue level. Impact: IGFBP-3 is a prostate cancer risk factor but 25(OH)D are unlikely to be causally related to IGFBP-3 in the circulation.

Original languageEnglish (US)
Pages (from-to)1462-1471
Number of pages10
JournalCancer Epidemiology Biomarkers and Prevention
Issue number12
StatePublished - Dec 2018


Cite this