Daily Axillary Temperature ΔT and Cognitive-Autonomic Patterns in Free-Living Adults: Identification of Stress-Energy Response Phenotypes in an Observational Cohort

Axillary temperature oscillation (Delta T; night-minus-morning) serves as an accessible ecological proxy for autonomic coherence and energetic resistance to stress (eR), reflecting regulation by the suprachiasmatic nucleus and core clock genes (PER, CRY, CLOCK, BMAL1). The Energy Resistance Principle (ERP) posits that elevated eR promotes oxidative stress, inflammation, and accelerated aging. The MiSBIE index (Mindful Self-Biofeedback Index of Embodiment) is a validated six-domain cognitive-autonomic metric (mental clarity, energetic vitality, emotional balance, tension release, bodily interoception, and subjective rhythmic synchrony; r = 0.78 vs EEG/HRV; Cronbach alpha = 0.89). This 15-day prospective ecological study in free-living routine evaluated Delta T, MiSBIE variation, morning light exposure, and nighttime screen use as real-world proxies of eR in 16 adults (9 F, 7 M; mean age 58.35 +/- 7.8 years), achieving 100 percent adherence (239 of 240 records). Delta T greater than 0 C identified elevated eR (r = 0.52 with perceived stress; 95 percent CI 0.38 to 0.64; p < 0.001). K-means clustering (k = 3) revealed three phenotypic patterns: Profile A (low eR and high coherence; n = 5): Delta T -0.17 +/- 0.21 C, MiSBIE change +4.82 +/- 1.98 (p = 0.0078); Profile B (high eR and incoherence; n = 6): Delta T +0.35 +/- 0.48 C (p < 0.001 vs A), MiSBIE change -2.11 +/- 3.42 (p = 0.0416); Profile C (compensated eR and hormesis; n = 5): Delta T +0.28 +/- 0.32 C, MiSBIE change +1.23 +/- 2.61 (p = 0.31). MiSBIE predicted 78 percent of eR variance (R2 = 0.78; p < 0.001). Morning light exposure greater than 15 minutes reduced eR (beta = -0.24 C; 95 percent CI -0.39 to -0.09; p = 0.002), while nighttime screen exposure correlated with lower MiSBIE (r = -0.32; p = 0.012). Limitations include axillary temperature bias (about -0.1 C vs core), self-reported behavioral variables, and the absence of continuous HRV or serum GDF15. Delta T combined with MiSBIE enables low-cost, real-world detection of eR phenotypes and supports algorithmic frameworks such as Verso 1.0 for early, light-based physiologic interventions aimed at restoring autonomic coherence and reducing aging-related risk.