Fetuin-A is Associated to Serum Calcium and AHSG T256S Genotype but Not to Coronary Artery Calcification
BIOCHEMICAL GENETICS
Authors: Bellia, Chiara; Agnello, Luisa; Lo Sasso, Bruna; Milano, Salvatore; Bivona, Giulia; Scazzone, Concetta; Pivetti, Alessia; Novo, Giuseppina; Palermo, Chiara; Bonomo, Vito; La Grutta, Ludovico; Midiri, Massimo; Novo, Salvatore; Ciaccio, Marcello
Abstract
Vascular calcification has been recently associated to an increased cardiovascular risk and mortality. In few studies, Fetuin-A showed an association to coronary artery calcification (CAC), although the physiopathological mechanism underlying this association has not been fully established yet. Seventy-four patients with one or more cardiovascular risk factor and asymptomatic for coronary vasculopathy were included in the study. CAC was evaluated by Agatston score. Serum Fetuin-A levels were determined by ELISA. Molecular analysis of AHSG T256S gene variant (rs4918) was performed by PCR-RFLP. Serum Fetuin-A was correlated to serum calcium (r = 0,321; P = 0,018), but not to serum phosphorous. Multivariate linear regression analysis confirmed this association and showed that calcium and AHSG genotype were independent predictors of Fetuin-A (P = 0.037, P = 0.014, respectively). In particular, subjects carrying the SS genotype had lower levels of Fetuin-A and calcium (P = 0.037 and P = 0.038, respectively). When we compare subjects with CAC 0-10 with subjects with CAC > 10, we found that only age and male gender (P < 0.001, P = 0.035, respectively), but not Fetuin-A, were associated to CAC. Fetuin-A is not associated to CAC in subjects with low cardiovascular risk profile and asymptomatic for coronary vasculopathy, suggesting that in this setting Fetuin-A, although correlated to serum levels of calcium, could be not involved in mineral deposition on coronary vessels.
Plasma fetuin-A concentration, genetic variation in the AHSG gene and risk of colorectal cancer
INTERNATIONAL JOURNAL OF CANCER
Authors: Nimptsch, Katharina; Aleksandrova, Krasimira; Boeing, Heiner; Janke, Juergen; Lee, Young-Ae; Jenab, Mazda; Kong, So Yeon; Tsilidis, Konstantinos K.; Weiderpass, Elisabete; Bueno-de-Mesquita, H. B(As); Siersema, Peter D.; Jansen, Eugene H. J. M.; Trichopoulou, Antonia; Tjonneland, Anne; Olsen, Anja; Wu, Chunsen; Overvad, Kim; Boutron-Ruault, Marie-Christine; Racine, Antoine; Freisling, Heinz; Katzke, Verena; Kaaks, Rudolf; Lagiou, Pagona; Trichopoulos, Dimitrios; Severi, Gianluca; Naccarati, Alessio; Mattiello, Amalia; Palli, Domenico; Grioni, Sara; Tumino, Rosario; Peeters, Petra H.; Ljuslinder, Ingrid; Nystrom, Hanna; Brandstedt, Jenny; Sanchez, Maria-Jose; Gurrea, Aurelio Barricarte; Bonet, Catalina Bonet; Chirlaque, Maria-Dolores; Dorronsoro, Miren; Quiros, Jose Ramon; Travis, Ruth C.; Khaw, Kay-Tee; Wareham, Nick; Riboli, Elio; Gunter, Marc J.; Pischon, Tobias
Abstract
Fetuin-A, also referred to as alpha 2-Heremans-Schmid glycoprotein (AHSG), is a liver protein known to inhibit insulin actions. Hyperinsulinemia is a possible risk factor for colorectal cancer; however, the role of fetuin-A in the development of colorectal cancer is unclear. We investigated the association between circulating fetuin-A and colorectal cancer risk in a nested case-control study within the European Prospective Investigation into Cancer and Nutrition. Fetuin-A concentrations were measured in prediagnostic plasma samples from 1,367 colorectal cancer cases and 1,367 matched controls. In conditional logistic regression models adjusted for potential confounders, the estimated relative risk (95% confidence interval) of colorectal cancer per 40 mg/mL higher fetuin-A concentrations (approximately one standard deviation) was 1.13 (1.02-1.24) overall, 1.21 (1.05-1.39) in men, 1.06 (0.93-1.22) in women, 1.13 (1.00-1.27) for colon cancer and 1.12 (0.94-1.32) for rectal cancer. To improve causal inference in a Mendelian Randomization approach, five tagging single nucleotide polymorphisms of the AHSG gene were genotyped in a subset of 456 case-control pairs. The AHSG allele-score explained 21% of the interindividual variation in plasma fetuin-A concentrations. In instrumental variable analysis, genetically raised fetuin-A was not associated with colorectal cancer risk (relative risk per 40 mg/mL genetically determined higher fetuin-A was 0.98, 95% confidence interval: 0.73-1.33). The findings of our study indicate a modest linear association between fetuin-A concentrations and risk of colorectal cancer but suggest that fetuin-A may not be causally related to colorectal cancer development.