Plasma amyloid beta predicts conversion to dementia in subjects with mild cognitive impairment: The BALTAZAR study
Olivier Hanon, Jean‐Sébastien Vidal, Sylvain Lehmann, Stéphanie Bombois, Bernadette Allinquant, Christiane Baret‐Rose, Jean‐Marc Tréluyer, Hendy Abdoul, Patrick Gelé, Christine Delmaire, Frédéric Blanc, Jean‐François Mangin, Luc Buée, Jacques Touchon, Jacques Hugon, Bruno Vellas, Evelyne Galbrun, Athanase Bénétos, Gilles Berrut, Éléna Paillaud, David Wallon, Giovanni Castelnovo, Lisette Volpe‐Gillot, Marc Paccalin, Philippe Robert, Olivier Godefroy, Vincent Camus, Joël Belmin, Pierre Vandel, Jean‐Luc Novella, Emmanuelle Duron, Anne‐Sophie Rigaud, Susanna Schraen‐Maschke, Audrey Gabelle, the BALTAZAR study group
Abstract
Abstract Introduction Blood‐based biomarkers are the next challenge for Alzheimer's disease (AD) diagnosis and prognosis. Methods Mild cognitive impairment (MCI) participants (N = 485) of the BALTAZAR study, a large‐scale longitudinal multicenter cohort, were followed‐up for 3 years. A total of 165 of them converted to dementia (95% AD). Associations of conversion and plasma amyloid beta (Aβ) 1‐42 , Aβ 1‐40 , Aβ 1‐42 /Aβ 1‐40 ratio were analyzed with logistic and Cox models. Results Converters to dementia had lower level of plasma Aβ 1‐42 (37.1 pg/mL [12.5] vs. 39.2 [11.1] , P value = .03) and lower Aβ 1‐42 /Aβ 1‐40 ratio than non‐converters (0.148 [0.125] vs. 0.154 [0.076], P value = .02). MCI participants in the highest quartile of Aβ 1‐42 /Aβ 1‐40 ratio (>0.169) had a significant lower risk of conversion (hazard ratio adjusted for age, sex, education, apolipoprotein E ε4, hippocampus atrophy = 0.52 (95% confidence interval [0.31–0.86], P value = .01). Discussion In this large cohort of MCI subjects we identified a threshold for plasma Aβ 1‐42 /Aβ 1‐40 ratio that may detect patients with a low risk of conversion to dementia within 3 years.