Liu, Ziyue, Cappola, Anne R, Crofford, Leslie J et al. · Journal of the American Statistical Association · 2014 · DOI
This study developed a new statistical method to track how stress hormones change over time in people with ME/CFS and fibromyalgia. The researchers found that in patients with these conditions, the two main stress hormones (ACTH and cortisol) don't work together as well as they do in healthy people, suggesting their stress-response system may function differently.
Abnormalities in the HPA axis have long been hypothesized in ME/CFS pathophysiology. This methodological advance enables more sophisticated detection and characterization of hormonal dysregulation in ME/CFS, potentially revealing subtle neuroendocrine dysfunction that simpler statistical approaches might miss, which could inform mechanistic understanding and diagnostic biomarker development.
This is a methodological paper demonstrating a statistical technique rather than a primary biological study; it does not establish causation or fully characterize HPA axis dysfunction in ME/CFS. The weaker ACTH-cortisol relationship observed does not prove what underlying pathology causes it, nor does it establish whether this difference is a primary driver of illness or a secondary consequence.
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
The first block is for the primary paper and is the citation you should use in research work. The atlas-snapshot line only applies if you are specifically referring to this atlas’s reading of the paper on the date shown.
Primary citation
Liu, Ziyue, Cappola, Anne R, Crofford, Leslie J, & Guo, Wensheng (2014). Modeling Bivariate Longitudinal Hormone Profiles by Hierarchical State Space Models.. Journal of the American Statistical Association. https://doi.org/10.1080/01621459.2013.830071
BibTeX
@article{mecfsatlas-liu-2014-modeling-bivariate,
author = {Liu, Ziyue and Cappola, Anne R and Crofford, Leslie J and Guo, Wensheng},
title = {Modeling Bivariate Longitudinal Hormone Profiles by Hierarchical State Space Models.},
journal = {Journal of the American Statistical Association},
year = {2014},
doi = {10.1080/01621459.2013.830071},
note = {PubMed: 24729646},
url = {https://www.mecfsatlas.com/evidence/liu-2014-modeling-bivariate},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-27. https://www.mecfsatlas.com/evidence/liu-2014-modeling-bivariate
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