Chronic analgesic use blunts nociceptor signaling that normally triggers release of damage‑associated extracellular vesicles (EVs) containing ATP, HMGB1, and specific miRNAs. These EVs act as circulating hormetic cues that engage TLR4 on peripheral tissues, leading to LKB1‑mediated AMPK activation, increased autophagic flux, and NAD+ salvage—processes linked to slower epigenetic aging. We hypothesize that long‑term opioid or high‑dose NSAID therapy reduces EV‑borne stress signals, thereby dampening AMPK‑autophagy pathways and accelerating DNAm‑clock progression independent of overdose risk.

To test this, we propose a prospective cohort of adults with chronic non‑cancer pain stratified into three groups: (1) long‑term opioid users, (2) regular NSAID users, and (3) analgesic‑free controls matched for pain severity, age, BMI, and comorbidities. At baseline, 6 months, and 12 months we will collect plasma to quantify EV concentration (NTA), EV‑HMGB1 and EV‑miR‑21 levels (ELISA/qPCR), phospho‑AMPK (Western blot), and LC3‑II/I ratios in isolated PBMCs. Parallel whole‑blood DNA methylation will be assessed using the GrimAge and PhenoAge clocks. Mixed‑effects models will test whether EV‑HMGB1 mediates the relationship between analgesic exposure and change in GrimAge acceleration, adjusting for confounders.

We further predict that in vivo blockade of EV release in mice (using GW4869) will recapitulate the epigenetic aging signature seen with chronic morphine administration, whereas exogenous administration of nociceptor‑derived EVs will rescue AMPK activity and GrimAge slowing in opioid‑treated animals. Conversely, if analgesic groups show no difference in EV markers, phospho‑AMPK, or epigenetic age trajectories compared with controls, the hypothesis would be falsified.

This framework extends the observed mortality hazard (HR 1.6 for long‑term opioid therapy [Long‑term opioid therapy and mortality]) by linking acute nociceptive silencing to a measurable cellular aging mechanism. It also aligns with prior work showing pain‑induced inflammation overlaps with DNA repair via PARP [COX‑2/PARP crosstalk] and that caloric restriction mitigates age‑related neuroinflammation and pain hypersensitivity [CR and pain], reinforcing the idea that nociception is an integral arm of systemic stress‑sensing hormesis.