[Note: to read the full text of this free access article, click HERE. The 'stress mediating' neurotransmitter neuropeptide Y is a major factor in the brain and body. For example, it affects food intake, anxiety, learning and memory, the cardiovascular system (e.g., contraction of vascular smooth muscle) and the neuroendocrine system/hormone secretion.]
Chronic fatigue syndrome (CFS) is a complex, multi-symptom illness with a multisystem pathogenesis involving alterations in the nervous, endocrine and immune systems.
Abnormalities in stress responses have been identified as potential triggers or mediators of CFS symptoms.
This study focused on the stress mediator neuropeptide Y (NPY). We hypothesized that NPY would be a useful biomarker for CFS.
The CFS patients (n=93) were from the Chronic Fatigue and Related Disorders Clinic at the University of Miami and met the 1994 case definition of Fukuda and colleagues.
Healthy sedentary controls (n=100)) were from NIH or VA funded studies.
Another fatiguing, multi-symptom illness, Gulf War Illness (GWI), was also compared to CFS.
We measured mediator neuropeptide Y (NPY) in plasma using a radioimmunoassay (RIA).
Psychometric measures, available for a subset of CFS patients, included: Perceived Stress Scale, Profile of Mood States, ATQ Positive &Negative Self-Talk Scores, the COPE, the Beck Depression Inventory, Fatigue Symptom Inventory, Cognitive Capacity Screening Examination, Medical Outcomes Survey Short Form-36, and the Quality of Life Scale.
Plasma NPY was elevated in CFS subjects, compared to controls (p=.000) and to GWI cases (p=.000).
Receiver operating characteristics (ROC) curve analyses indicated that the predictive ability of plasma NPY to distinguish CFS patients from healthy controls and from GWI was significantly better than chance alone.
In 42 patients with CFS, plasma NPY had significant correlations (<0.05) with perceived stress, depression, anger/hostility, confusion, negative thoughts, positive thoughts, general health, and cognitive status.
In each case the correlation (+ or -) was in the anticipated direction.
Conclusions: This study is the first in the CFS literature to report that plasma NPY is elevated compared to healthy controls and to a fatigued comparison group, GWI patients.
The significant correlations of NPY with stress, negative mood, general health, depression and cognitive function strongly suggest that this peptide be considered as a biomarker to distinguish subsets of CFS.
Source: Behavioral and Brain Functions, Dec 29, 2010;#6,p76. PMID, by Fletcher M, Rosenthal M, Antoni M, Ironson G, Zeng X, Barnes Z, Harvey J, Hurwitz B, Levis S, Broderick G, Klimas N. Department of Medicine, University of Miami Miller School of Medicine, Miami, Department of Psychology, University of Miami, Coral Gables, and Miami Veterans Administration Health Care Center, Miami, Florida, USA; Department of Medicine, University of Alberta, Canada.[Email: email@example.com; firstname.lastname@example.org; email@example.com]