Caroline Trumpff1, Anna L Marsland2, Richard P Sloan1, Brett A Kaufman3, Martin Picard4. 1. Department of Psychiatry, Division of Behavioral Medicine, Columbia University Irving Medical Center, New York, NY, 10032, USA. 2. Department of Psychology, University of Pittsburgh, Pittsburgh, PA, 15260, USA. 3. University of Pittsburgh School of Medicine, Division of Cardiology, Center for Metabolism and Mitochondrial Medicine and Vascular Medicine Institute, Pittsburgh, PA, 15261, USA. 4. Department of Psychiatry, Division of Behavioral Medicine, Columbia University Irving Medical Center, New York, NY, 10032, USA; Department of Neurology, H. Houston Merritt Center, Columbia Translational Neuroscience Initiative, Columbia University Irving Medical Center, New York, NY, 10032, USA; Columbia Aging Center, Columbia University Mailman School of Public Health, New York, NY, 10032, USA. Electronic address: martin.picard@columbia.edu.
Abstract
OBJECTIVE: We have previously found that acute psychological stress may affect mitochondria and trigger an increase in serum mitochondrial DNA, known as circulating cell-free mtDNA (ccf-mtDNA). Similar to other stress reactivity measures, there are substantial unexplained inter-individual differences in the magnitude of ccf-mtDNA reactivity, as well as within-person differences across different occasions of testing. Here, we sought to identify psychological and physiological predictors of ccf-mtDNA reactivity using machine learning-based multivariate classifiers. METHOD: We used data from serum ccf-mtDNA concentration measured pre- and post-stress in 46 healthy midlife adults tested on two separate occasions. To identify variables predicting the magnitude of ccf-mtDNA reactivity, two multivariate classification models, partial least-squares discriminant analysis (PLS-DA) and random forest (RF), were trained to discriminate between high and low ccf-mtDNA responders. Potential predictors used in the models included state variables such as physiological measures and affective states, and trait variables such as sex and personality measures. Variables identified across both models were considered to be predictors of ccf-mtDNA reactivity and selected for downstream analyses. RESULTS: Identified predictors were significantly enriched for state over trait measures (X2 = 7.03; p = 0.008) and for physiological over psychological measures (X2 = 4.36; p = 0.04). High responders were more likely to be male (X2 = 26.95; p < 0.001) and differed from low-responders on baseline cardiovascular and autonomic measures, and on stress-induced reduction in fatigue (Cohen's d = 0.38-0.73). These group-level findings also accurately accounted for within-person differences in 90% of cases. CONCLUSION: These results suggest that acute cardiovascular and psychological indices, rather than stable individual traits, predict stress-induced ccf-mtDNA reactivity. This work provides a proof-of-concept that machine learning approaches can be used to explore determinants of inter-individual and within-person differences in stress psychophysiology.
OBJECTIVE: We have previously found that acute psychological stress may affect mitochondria and trigger an increase in serum mitochondrial DNA, known as circulating cell-free mtDNA (ccf-mtDNA). Similar to other stress reactivity measures, there are substantial unexplained inter-individual differences in the magnitude of ccf-mtDNA reactivity, as well as within-person differences across different occasions of testing. Here, we sought to identify psychological and physiological predictors of ccf-mtDNA reactivity using machine learning-based multivariate classifiers. METHOD: We used data from serum ccf-mtDNA concentration measured pre- and post-stress in 46 healthy midlife adults tested on two separate occasions. To identify variables predicting the magnitude of ccf-mtDNA reactivity, two multivariate classification models, partial least-squares discriminant analysis (PLS-DA) and random forest (RF), were trained to discriminate between high and low ccf-mtDNA responders. Potential predictors used in the models included state variables such as physiological measures and affective states, and trait variables such as sex and personality measures. Variables identified across both models were considered to be predictors of ccf-mtDNA reactivity and selected for downstream analyses. RESULTS: Identified predictors were significantly enriched for state over trait measures (X2 = 7.03; p = 0.008) and for physiological over psychological measures (X2 = 4.36; p = 0.04). High responders were more likely to be male (X2 = 26.95; p < 0.001) and differed from low-responders on baseline cardiovascular and autonomic measures, and on stress-induced reduction in fatigue (Cohen's d = 0.38-0.73). These group-level findings also accurately accounted for within-person differences in 90% of cases. CONCLUSION: These results suggest that acute cardiovascular and psychological indices, rather than stable individual traits, predict stress-induced ccf-mtDNA reactivity. This work provides a proof-of-concept that machine learning approaches can be used to explore determinants of inter-individual and within-person differences in stress psychophysiology.
Authors: Bjoern H Menze; B Michael Kelm; Ralf Masuch; Uwe Himmelreich; Peter Bachert; Wolfgang Petrich; Fred A Hamprecht Journal: BMC Bioinformatics Date: 2009-07-10 Impact factor: 3.169
Authors: Caroline Trumpff; Jeremy Michelson; Claudia J Lagranha; Veronica Taleon; Kalpita R Karan; Gabriel Sturm; Daniel Lindqvist; Johan Fernström; Dirk Moser; Brett A Kaufman; Martin Picard Journal: Mitochondrion Date: 2021-04-09 Impact factor: 4.160