Interactions between Plasma Levels of 25-Hydroxyvitamin D, Insulin-Like Growth Factor (IGF)-1 and C-Peptide with Risk of Colorectal Cancer

Background: Vitamin D status and levels of insulin-like growth factor (IGF)-1 and C-peptide have been implicated in colorectal carcinogenesis. However, in contrast to vitamin D IGF-1 is not an easily modifiable risk factor. Methods: Combining data from the Health Professionals Follow up Study (HPFS) and the Nurses' Health Study cohort (NHS) additive and multiplicative interactions were examined between plasma 25-hydroxyvitamin D (25(OH)D) and IGF-1, IGFBP-3 as well as C-peptide levels in 499 cases and 992 matched controls. For the various analytes, being high or low was based on being either above (or equal) or below the medians, respectively. Results: Compared to participants with high 25(OH)D and low IGF-1/IGFBP-3 ratio (reference group), participants with a high IGF-1/IGFBP-3 ratio were at elevated risk of colorectal cancer when 25(OH)D was low (odds ratio (OR): 2.05 (95% CI: 1.43 to 2.92), but not when 25(OH)D was high (OR:1.20 (95% CI: 0.84 to 1.71, p(interaction): additive = 0.06, multiplicative = 0.25). Similarly, compared to participants with high 25(OH)D and low molar IGF-1/IGFBP-3 ratio and low C-peptide levels (reference group), participants with a combination of either high IGF-1/IGFBP-3 ratio or high C-peptide were at elevated risk for colorectal cancer when 25(OH)D was low (OR = 1.90, 95% CI: 1.22 to 2.94) but not when 25(OH)D was high (OR = 1.15, 95% CI: 0.74 to 1.77, p(interaction): additive = 0.004; multiplicative = 0.04). Conclusion: The results from this study suggest that improving vitamin D status may help lower risk of colorectal cancer associated with higher IGF-1/IGFBP-3 ratio or C-peptide levels

Transatlantic Perspectives on Liberalization and Democratic Governance

The first volume of the new Transatlantic Public Policy Series comprises contributions by members of the Transatlantic Policy Consortium (TPC). Earlier versions of the papers published in this volume have been presented and discussed at the TPC Colloquium in Speyer, Germany, in June 2003 on the theme of Liberalization and Democratic Governance. They centre around subthemes which are critical on both sides of the Atlantic: the role of the state with social and economic actors, policy development and regulatory challenges to the state and the changing nature of democratic institutions and participation. Some contributions represent updated versions of papers originally prepared for the TPC Colloquium in Pittsburgh, Pennsylvania/USA, in September 2001 on public service ethics at both national and international levels. The earlier publication of these papers fell victim to the terrorist attacks of that time. The volume provides a unique insight into European and US-American public policy issues and thinking. Ernst Ulrich von Weizsäcker made a remarkable contribution on "The Old and New Europe: Alternatives for Future Transatlantic Relations?" Three professors based at the German University of Administrative Sciences contributed to this volume: Stefan Fisch ("The 1832 Mass Rally for Democracy in Germany and Europe in Hambach Castle"), Siegfried Magiera ("The Role of Parliaments in the Future Architecture of the European Union"), and Hans Herbert von Arnim ("Institutionalized Political Unaccountability and Political Corruption in Germany")