• Circulating concentrations of biomarkers and metabolites related to Vitamin status, one-carbon and the kynurenine pathways in US, Nordic, Asian, and Australian populations 

      Midttun, Øivind; Theofylaktopoulou, Despoina; Mccann, Adrian; Fanidi, Anouar; Muller, David C.; Meyer, Klaus; Ulvik, Arve; Zheng, Wei; Shu, Xiao-Ou; Xiang, Yong-Bing; Prentice, Ross; Thomson, Cynthia A.; Pettinger, Mary; Giles, Graham G.; Hodge, Allison; Cai, Qiuyin; Blot, William J.; Wu, Jie; Johansson, Mikael; Hultdin, Johan; Grankvist, Kjell; Stevens, Victoria L.; McCullough, Marjorie L.; Weinstein, Stephanie J.; Albanes, Demetrius; Langhammer, Arnulf; Hveem, Kristian; Næss, Marit; Sesso, Howard D.; Gaziano, J. Michael; Buring, Julie E.; Lee, I-Min; Severi, Gianluca; Zhang, Xuehong; Han, Jiali; Stampfer, Meir J.; Smith-Warner, Stephanie A.; Zeleniuch-Jacquotte, Anne; Le Marchand, Loic; Yuan, Jian-Min; Butler, Lesley M.; Koh, Woon-Puay; Wang, Renwei; Gao, Yu-Tang; Ericson, Ulrika; Sonestedt, Emily; Ziegler, Regina G.; Freedman, Neal D.; Visvanathan, Kala; Jones, Miranda R.; Relton, Caroline; Brennan, Paul; Johansson, Mattias; Ueland, Per Magne (Peer reviewed; Journal article, 2017-06)
      Background: Circulating concentrations of biomarkers that are related to vitamin status vary by factors such as diet, fortification, and supplement use. Published biomarker concentrations have also been influenced by the ...
    • The effect of electroconvulsive therapy (ECT) on serum tryptophan metabolites 

      Aarsland, Tore Ivar Malmei; Leskauskaite, Ieva; Midttun, Øivind; Ulvik, Arve; Ueland, Per Magne; Oltedal, Leif; Erchinger, Vera Jane; Ødegaard, Ketil Joachim; Haavik, Jan; Kessler, Ute (Peer reviewed; Journal article, 2019-05-31)
      Background: Prior studies suggest that activation of the tryptophan catabolism via the kynurenine pathway by proinflammatory cytokines may be involved in the pathophysiology of depression. Electroconvulsive therapy (ECT) ...
    • Impact of Pre-Pregnancy BMI on B Vitamin and Inflammatory Status in Early Pregnancy: An Observational Cohort Study 

      Monsen, Anne Lise Bjørke; Ulvik, Arve; Nilsen, Roy Miodini; Midttun, Øivind; Roth, Christine; Magnus, Per; Stoltenberg, Camilla; Vollset, Stein Emil; Reichborn-Kjennerud, Ted; Ueland, Per Magne (Peer reviewed; Journal article, 2016-11-30)
      Maternal nutrition and inflammation have been suggested as mediators in the development of various adverse pregnancy outcomes associated with maternal obesity. We have investigated the relation between pre-pregnancy BMI, ...
    • Inflammatory markers, the tryptophan-kynurenine pathway, and Vitamin B status after bariatric surgery 

      Christensen, Monika; Fadnes, Dag Jone Stokke; Røst, Therese Halvorsen; Pedersen, Eva Ringdal; Andersen, John Roger; Våge, Villy; Ulvik, Arve; Midttun, Øivind; Ueland, Per Magne; Nygård, Ottar; Mellgren, Gunnar (Peer reviewed; Journal article, 2018-02-05)
      Objective: Obesity is associated with increased inflammation and insulin resistance. In conditions with chronic immune activation, low plasma vitamin B6-levels are described, as well as an increased kynurenine:tryptophan-ratio ...
    • Interferon (IFN)-γ-mediated inflammation and the kynurenine pathway in relation to bone mineral density: the Hordaland Health Study 

      Apalset, Ellen M.; Gjesdal, Clara Gram; Ueland, Per Magne; Midttun, Øyvind; Ulvik, Arve; Eide, Geir Egil; Meyer, Klaus; Tell, Grethe Seppola (Peer reviewed; Journal article, 2014-04-24)
      The risk of osteoporosis increases in inflammatory disorders. In cell-mediated immune activation, interferon (IFN)-γ stimulates macrophage release of neopterin and increases the activity of indoleamine 2,3-dioxygenase ...
    • Interferon-γ–induced inflammatory markers and the risk of cancer: The Hordaland Health Study 

      Zuo, Hui; Tell, Grethe Seppola; Vollset, Stein Emil; Ueland, Per Magne; Nygård, Ottar; Midttun, Øivind; Meyer, Klaus; Ulvik, Arve; Eussen, Simone (Peer reviewed; Journal article, 2014-06-19)
      Background It has been reported that interferon-γ (IFN-γ)–induced inflammatory markers, such as circulating neopterin and kynurenine-to-tryptophan ratio (KTR), are increased in patients with cancer and are also a predictor ...
    • Markers of vitamin B6 status and metabolism as predictors of incident cancer: The Hordaland Health Study. 

      Zuo, Hui; Ueland, Per Magne; Eussen, Simone; Tell, Grethe Seppola; Vollset, Stein Emil; Nygård, Ottar; Midttun, Øivind; Meyer, Klaus; Ulvik, Arve (Peer reviewed; Journal article, 2014-11-26)
      Dietary intake and/or circulating concentrations of vitamin B6 have been associated with risk of cancer, but results are inconsistent and mechanisms uncertain. Pyridoxal 5'-phosphate (PLP) is the most commonly used marker ...
    • The PAr index, an indicator reflecting altered vitamin B-6 homeostasis, is associated with long-term risk of stroke in the general population: the Hordaland Health Study (HUSK) 

      Zuo, Hui; Tell, Grethe S.; Ueland, Per Magne; Nygård, Ottar; Vollset, Stein Emil; Midttun, Øivind; Meyer, Klaus; Ulvik, Arve (Peer reviewed; Journal article, 2018-01)
      Background: Vitamin B-6 homeostasis is altered during inflammation and immune activation. It is unknown whether altered vitamin B-6 homeostasis is associated with the risk of stroke. Objective: We investigated the relation ...
    • Plasma Biomarkers of Inflammation, the Kynurenine Pathway, and Risks of All-Cause, Cancer, and Cardiovascular Disease Mortality. The Hordaland Health Study 

      Zuo, Hui; Ueland, Per Magne; Ulvik, Arve; Eussen, Simone; Vollset, Stein Emil; Nygård, Ottar; Midttun, Øivind; Theofylaktopoulou, Despoina; Meyer, Klaus; Tell, Grethe Seppola (Peer reviewed; Journal article, 2016)
      We aimed to evaluate 10 biomarkers related to inflammation and the kynurenine pathway, including neopterin, kynurenine:tryptophan ratio, C-reactive protein, tryptophan, and 6 kynurenines, as potential predictors of all-cause ...
    • Plasma concentrations and dietary intakes of choline and betaine in association with atrial fibrillation risk: Results from 3 prospective cohorts with different health profiles 

      Zuo, Hui; Svingen, Gard Frodahl Tveitevåg; Tell, Grethe S.; Ueland, Per Magne; Vollset, Stein Emil; Pedersen, Eva Ringdal; Ulvik, Arve; Meyer, Klaus; Nordrehaug, Jan Erik; Nilsen, Dennis W.T.; Bønaa, Kaare; Nygård, Ottar (Peer reviewed; Journal article, 2018)
      Background: Although choline metabolism has been associated with atherosclerotic heart disease, less research attention has been paid to the associations of choline and its oxidative metabolite betaine with cardiac ...
    • Plasma methionine, choline, betaine, and dimethylglycine in relation to colorectal cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) 

      Nitter, Mathilde Hjelle; Norgård, Benedicte Wentzel; De Vogel, Stefan; Eussen, Simone; Meyer, Klaus; Ulvik, Arve; Ueland, Per Magne; Nygård, Ottar; Vollset, Stein Emil; Bjørge, Tone; Tjønneland, Anne; Hansen, Louise; Boutron-Ruault, Marie-Christine; Racine, Antoine; Cottet, Vanessa; Kaaks, Rudolf; Kühn, Tilman; Trichopoulou, Antonia; Bamia, Christina; Naska, Androniki; Grioni, Sara; Palli, Domenico; Panico, Salvatore; Tumino, Rosario; Vineis, Paolo; Bueno-de-Mesquita, H. Bas; Van Kranen, Henk J.; Peeters, Petra H. M.; Weiderpass, Elisabete; Dorronsoro, Miren; Jakszyn, Paula; Sánchez, María-José; Argüelles, Marcial Vicente; Huerta, José-Maria; Barricarte, Aurelio; Johansson, Matthias; Ljuslinder, Ingrid; Khaw, Kay Tee; Wareham, Nicholas J.; Freisling, Heinz; Duarte-Salles, Talita; Stepien, Magdalena; Gunter, Mark J.; Riboli, Élio B. (Peer reviewed; Journal article, 2014-08)
      Background Disturbances in one carbon metabolism may contribute to carcinogenesis by affecting methylation and synthesis of DNA. Choline and its oxidation product betaine are involved in this metabolism and can serve as ...
    • Serum concentrations of kynurenines in adult patients with attention-deficit hyperactivity disorder (ADHD): a case–control study 

      Hegvik, Tor-Arne; Ulvik, Arve; Halmøy, Anne; Haavik, Jan; Aarsland, Tore Ivar Malmei; Landaas, Elisabeth Toverud; Ueland, Per Magne (Peer reviewed; Journal article, 2015-11-05)
      Background: The essential amino acid tryptophan is catabolised mainly through the kynurenine pathway. Altered circulating levels of kynurenines have been reported in chronic inflammatory conditions and in several ...
    • Smoking, plasma cotinine and risk of atrial fibrillation: the Hordaland Health Study 

      Zuo, Hui; Nygård, Ottar; Vollset, Stein Emil; Ueland, Per Magne; Ulvik, Arve; Midttun, Øivind; Meyer, Klaus; Igland, Jannicke; Sulo, Gerhard; Tell, Grethe S. (Peer reviewed; Journal article, 2018-01)
      Background: Cigarette smoking has been identified as a major modifiable risk factor for coronary heart disease and mortality. However, findings on the relationship between smoking and atrial fibrillation (AF) have been ...
    • Tryptophan catabolites as metabolic markers of vitamin B-6 status evaluated in cohorts of healthy adults and cardiovascular patients 

      Ulvik, Arve; Midttun, Øivind; McCann, Adrian; Meyer, Klaus; Tell, Grethe S.; Nygård, Ottar; Ueland, Per Magne (Journal article; Peer reviewed, 2020)
      Background Vitamin B-6 status is routinely measured as pyridoxal 5′-phosphate (PLP) in plasma. Low concentrations of PLP are associated with rheumatic, cardiovascular, and neoplastic diseases. We have previously shown ...
    • Vitamin B6 catabolism and lung cancer risk: Results from the Lung Cancer Cohort Consortium (LC3) 

      Zuo, Hui; Ueland, Per Magne; Midttun, Øivind; Tell, Grethe S.; Fanidi, Anouar; Zheng, Wei; Shu, Xiao-Ou; Xiang, Yong-Bing; Wu, Jie; Prentice, Ross L.; Pettinger, Mary; Thomson, Cynthia A.; Giles, Graham G.; Hodge, Allison M.; Cai, Qiuyin; Blot, William J.; Johansson, Mikael B.; Hultdin, Johan; Grankvist, Kjell; Stevens, Victoria L.; McCullough, Marjorie L.; Weinstein, Stephanie J.; Albanes, Demetrius; Ziegler, Regina G.; Freedman, Neal David; Caporaso, Neil E.; Langhammer, Arnulf; Hveem, Kristian; Næss, Marit; Buring, Julie E.; Lee, I-Min; Gaziano, John Michael; Severi, Gianluca; Zhang, Xuehong; Stampfer, Meir Jonathan; Han, Jiali; Zeleniuch-Jacquotte, Anne; Marchand, Loïc Le; Yuan, Jian-Min; Wang, Renwei; Koh, Woon-Puay; Gao, Yutang; Ericson, Ulrika C.; Visvanathan, Kala; Jones, Michael R.; Relton, Caroline Laura; Brennan, Paul J.; Johansson, Mattias; Ulvik, Arve (Journal article; Peer reviewed, 2019-03)
      Background Increased vitamin B6 catabolism related to inflammation, as measured by the PAr index (the ratio of 4-pyridoxic acid over the sum of pyridoxal and pyridoxal-5'-phosphate), has been positively associated with ...