ANS Imbalance and Accelerated Aging
1 Errico et al. 2025 — Sympathetic-Parasympathetic Deregulation Theory of Aging
Full Citation:: Errico JP, Ben-Azu B, Gargus M, Newell Rogers MK, Tremblay M-È. Sympathetic-parasympathetic system deregulation theory of aging. npj Aging. 2025;11:100. (Errico et al. 2025) DOI:: 10.1038/s41514-025-00293-2 PMID:: 41402304 · PMCID:: PMC12708862 Article Type:: Perspective (theoretical framework; no original data) Key Findings::
- Proposes chronic sympathetic dominance as unifying driver of all 9 hallmarks of aging (Lopez-Otin framework)
- SNS pathway: catecholamines/NADPH oxidase→ROS→mtDNA damage; PKA/cAMP→AMPK inhibition→blocked autophagy; beta-AR desensitization→NF-κB inflammaging
- PNS pathway: alpha7-nAChR→NF-κB inhibition/JAK2-STAT3/pro-resolving mediators; PGC-1α→mitochondrial biogenesis; cortisol→gut permeability/dysbiosis
- VNS proposed as therapeutic target; empirical longevity studies called forConclusion:: ANS balance may represent a master regulatory axis linking all hallmarks of aging. Rebalancing toward parasympathetic tone via pharmacological or device-based interventions is proposed as anti-aging strategy. Limitations:: Theoretical perspective only; no primary data; no ME/CFS patient data; causal claims unverified; VNS longevity evidence sparse. ME/CFS Relevance:: ANS imbalance is a core ME/CFS feature (sympathetic dominance, reduced HRV, orthostatic intolerance). This framework integrates mitochondrial dysfunction, inflammaging, cellular senescence, gut dysbiosis, and epigenetic degradation — all documented in ME/CFS — under a single ANS-imbalance model. Certainty Assessment::
- *Quality:* Medium (npj Aging, Nature Portfolio; but perspective only --- no data)
- *Sample:* N/A (theoretical)
- *Replication:* Framework not yet formally tested
- *Score:* 0.452 Giunta et al. 2024 — ANS Imbalance Impairs Anti-Inflammaging Strategies in Aging
Full Citation:: Giunta S, Xia S, Pelliccioni G, Olivieri F. Autonomic nervous system imbalance during aging contributes to impair endogenous anti-inflammaging strategies. GeroScience. 2024;46:113–127. (Giunta et al. 2024) DOI:: 10.1007/s11357-023-00947-7 PMID:: 37821752 · PMCID:: PMC10828245 Article Type:: Perspective review (no original data) Key Findings::
- Age-related ANS imbalance: sympathetic overactivity + parasympathetic decline progressively impair cholinergic anti-inflammatory pathway (CAP)
- HRV inversely correlates with IL-6 and CRP (systemic inflammation markers)
- Decreased vagal output associated with endothelial dysfunction and macrophage overactivation
- Both CAP and HPA axis responses diminish with age, reducing protective inflammation controlConclusion:: ANS imbalance is a primary mechanism sustaining inflammaging. Restoring vagal tone is proposed as an intervention point. Limitations:: Theoretical; limited sex-specific mechanistic data; no optimal HRV threshold defined for elderly risk stratification; no ME/CFS patient cohort. ME/CFS Relevance:: Directly supports the ANS-imbalance model for ME/CFS. Reduced HRV (parasympathetic decline) is well-documented in ME/CFS. The CAP impairment described here provides a mechanistic explanation for chronic low-grade inflammation in ME/CFS without clear infection. Certainty Assessment::
- *Quality:* Medium-High (GeroScience, high-impact aging journal; perspective)
- *Sample:* N/A (review)
- *Replication:* Reviewed evidence is replicated; framework itself not formally tested
- *Score:* 0.553 Balasubramanian et al. 2021 — Glial Senescence in Brainstem Drives Sympathetic Overactivity
Full Citation:: Balasubramanian P, Branen L, Sivasubramanian MK, Monteiro R, Subramanian M. Aging is associated with glial senescence in the brainstem — implications for age-related sympathetic overactivity. Aging (Albany NY). 2021;13(10):13460–13473. (Balasubramanian et al. 2021) DOI:: 10.18632/aging.203111 Study Design:: Mouse comparative study; young (2–4 months) vs. aged (24 months) Sample Size:: n=4–6 per group per measurement Key Findings::
- Aged brainstem: 32-fold increase in p16 mRNA; glial cells show 90-fold increase (senescence)
- Elevated nuclear NF-κB activity in aged brainstems, activating SASP genes
- Serum norepinephrine elevated in aged animals --- heightened sympathetic activity
- Elevated SASP cytokines/chemokines: IL-1β, MCP1, TNFα, Eotaxin, RANTESConclusion:: Glial senescence in the brainstem (sympathetic control centers) may drive age-related sympathetic overactivity via SASP-mediated neuroinflammation. Provides cellular mechanism for the SNS dominance described in Errico2025ANSaging. Limitations:: Mouse model only; associative (no causal proof); small n; unable to isolate neuronal senescence (no viable neurons extracted); no human validation. ME/CFS Relevance:: Brainstem abnormalities are documented in ME/CFS (e.g., microglial activation, neuroinflammation). Glial senescence as a driver of sympathetic overactivity provides a cellular substrate for ME/CFS ANS dysfunction that could be triggered by viral infection. Certainty Assessment::
- *Quality:* Medium (Aging Albany; animal study; small n)
- *Sample:* n=4--6 per group
- *Replication:* Not independently replicated in human tissue
- *Score:* 0.504 Kim et al. 2023 — Molecular Mechanisms of mtDNA Release and cGAS-STING Activation
Full Citation:: Kim J, Kim H-S, Chung JH. Molecular mechanisms of mitochondrial DNA release and activation of the cGAS-STING pathway. Experimental & Molecular Medicine. 2023;55(3):510–519. (Kim, Kim, and Chung 2023) DOI:: 10.1038/s12276-023-00965-7 PMID:: 36964253 · PMCID:: PMC10037406 Article Type:: Review Key Findings::
- cGAS senses cytosolic double-stranded DNA fragments; activates STING to initiate innate immune response
- mtDNA release via VDAC oligomerization macropores on outer mitochondrial membrane
- NLRP3 inflammasome requires oxidized mtDNA release for activation
- VDAC oligomerization inhibition mitigates inflammatory response; therapeutic implication
- Relevance to neurodegenerative conditions (ALS) discussedConclusion:: mtDNA release is a central link between mitochondrial stress and chronic innate immune activation. VDAC as a potential therapeutic target. Limitations:: Review article; no primary data; primarily pre-clinical mechanistic evidence. ME/CFS Relevance:: Provides the mechanistic bridge: SNS-driven NADPH oxidase→ROS→mtDNA oxidative damage→VDAC pore mtDNA release→cGAS-STING activation→sustained type-I interferon and NF-κB signaling. Consistent with elevated ccf-mtDNA reported in Long COVID (Matits2026) and hypothesized in ME/CFS. Certainty Assessment::
- *Quality:* Medium-High (Exp Mol Med, Nature Portfolio; review)
- *Sample:* N/A (review)
- *Replication:* Reviewed mechanisms well-established in pre-clinical models
- *Score:* 0.655 Park et al. 2023 — Redefining AMPK’s Role in Autophagy and Energy Stress
Full Citation:: Park J-M, Lee D-H, Kim D-H. Redefining the role of AMPK in autophagy and the energy stress response. Nature Communications. 2023;14(1):2994. (Park, Lee, and Kim 2023) DOI:: 10.1038/s41467-023-38401-z PMID:: 37225695 · PMCID:: PMC10209092 Study Design:: In vitro (HCT116, HEK293T, MEFs, HeLa cell lines) + in vivo mouse (liver, skeletal muscle) Key Findings::
- AMPK inhibits ULK1 (autophagy initiation kinase) during energy depletion via LKB1-AMPK axis
- Challenges prior model: AMPK does not promote autophagy during energy stress
- AMPK simultaneously protects autophagy machinery components from caspase degradation
- Recovery function: cells can restore autophagy capacity when stress resolvesConclusion:: AMPK has dual regulatory role in autophagy — suppressive during acute energy depletion, protective for long-term recovery. Refines how PKA/cAMP interference with AMPK impacts mitochondrial quality control. Limitations:: Cell culture and mouse models; no human tissue validation; no clinical conditions modeled. ME/CFS Relevance:: If chronic SNS activation (PKA/cAMP) inhibits AMPK, autophagy/mitophagy is suppressed, leading to accumulation of dysfunctional mitochondria. This directly supports the Errico2025ANSaging AMPK pathway and is consistent with ME/CFS mitochondrial dysfunction literature. Certainty Assessment::
- *Quality:* High (Nature Communications; rigorous mechanistic study)
- *Sample:* Multiple cell lines + mouse tissue
- *Replication:* Pre-clinical; mechanistic findings robust
- *Score:* 0.656 Rajeevan et al. 2018 — ME/CFS Associated with Premature Telomere Attrition
Full Citation:: Rajeevan MS, Murray J, Oakley L, Lin J-MS, Unger ER. Association of chronic fatigue syndrome with premature telomere attrition. Journal of Translational Medicine. 2018;16(1):44. (Rajeevan et al. 2018) DOI:: 10.1186/s12967-018-1414-x PMID:: 29486769 Study Design:: Cross-sectional; 4-group classification (CFS / CFS-X / ISF / non-fatigued controls); 1994 Fukuda criteria Sample Size:: n=639 (64 CFS, 77 CFS-X, 302 ISF, 196 NF) Key Findings::
- Mean telomere length differed significantly across groups ($p$=0.0017)
- CFS: telomeres shorter by 957 bp vs.\ controls, equivalent to 10.1--20.5 years additional biological aging
- ISF (insufficient symptoms): 424 bp shorter (6.6--13.7 years additional aging)
- Effect largely moderated by female subjects under 45 years old
- Differences persisted after adjusting for age, BMI, covariatesConclusion:: ME/CFS is associated with measurable accelerated biological aging via telomere attrition, consistent with the ANS-imbalance aging framework. Limitations:: Cross-sectional; 1994 Fukuda criteria (broader than ICC/CCC); causality unclear; telomere length as aging proxy has limitations; sex/age interaction limits generalizability. ME/CFS Relevance:: Direct evidence of accelerated biological aging in ME/CFS. Connects to Errico2025ANSaging framework: if chronic ANS imbalance drives aging hallmarks, ME/CFS patients’ accelerated telomere attrition is an expected downstream consequence. Certainty Assessment::
- *Quality:* Medium (J Transl Med; cross-sectional; single time point)
- *Sample:* n=639; adequate
- *Replication:* Not independently replicated with newer diagnostic criteria cohorts
- *Score:* 0.607 Luo et al. 2025 — Immunosenescence and Physical Fatigue in ME/CFS
Full Citation:: Luo Y, Xu H, Xiong S, Ke J. Understanding Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Physical Fatigue Through the Perspective of Immunosenescence. Comprehensive Physiology. 2025;15(5):e70056. (Luo et al. 2025) DOI:: 10.1002/cph4.70056 PMID:: 41017304 Article Type:: Narrative review Key Findings::
- Immunosenescence (aging immune cells) drives chronic inflammation impairing mitochondrial ATP production in ME/CFS
- HPA-axis suppression + beta2-adrenergic dysfunction amplify immune aging pathology
- Cross-organ communication (immune--muscular--neuroendocrine--vascular) sustains fatigue cycle
- Muscle catabolism promoted by SASP-driven inflammatory environment
- Proposed biomarkers include cytokines and immune exhaustion markersConclusion:: Immunosenescence provides a unifying pathophysiological framework for ME/CFS physical fatigue, linking immune aging to energy failure. Limitations:: Narrative review; no original data; proposed biomarkers not validated in ME/CFS-specific cohorts. ME/CFS Relevance:: Directly applies immunosenescence framework to ME/CFS. Beta2-adrenergic dysfunction connects to ANS-imbalance literature. Mitochondrial ATP impairment links to core ME/CFS energy failure phenotype. Certainty Assessment::
- *Quality:* Medium (Comprehensive Physiology; review)
- *Sample:* N/A (review)
- *Replication:* Synthesizes partially replicated findings
- *Score:* 0.558 Xu et al. 2026 — Immunosenescence-Driven Hemodynamic Dysregulation and Cognitive Impairment in ME/CFS
Full Citation:: Xu H, Luo Y, Wu X. Immunosenescence-Driven Hemodynamic Dysregulation and Cognitive Impairment in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: An Integrative Perspective. Comprehensive Physiology. 2026;16(1):e70098. (Xu, Luo, and Wu 2026) DOI:: 10.1002/cph4.70098 PMID:: 41527963 Article Type:: Review Key Findings::
- Proposes immune-vascular-cognitive axis: immunosenescence→chronic inflammation→impaired cerebral blood flow and nitric oxide production
- Brain hypoperfusion reduces neuronal energy availability → cognitive dysfunction
- BBB compromise, oxidative stress, neurotransmitter imbalance contribute to brain fog
- Suggests therapeutic targets: cytokine blockade, nitric oxide enhancementConclusion:: Brain fog in ME/CFS can be mechanistically explained through an immune aging→vascular→cognitive cascade, extending the immunosenescence framework from physical to cognitive fatigue. Limitations:: Review article; no original data; therapeutic suggestions speculative; ME/CFS-specific hemodynamic data limited. ME/CFS Relevance:: Extends Luo2025MECFSimmunophysiology to cognitive impairment. Aligns with established ME/CFS findings: reduced cerebral blood flow, orthostatic hypoperfusion, brain fog. Provides ANS-aging bridge to neurological symptom domain. Certainty Assessment::
- *Quality:* Medium (Comprehensive Physiology; review)
- *Sample:* N/A (review)
- *Replication:* Synthesizes emerging data; not independently validated
- *Score:* 0.50