A Proposed Randomized Controlled Trial Design: Testing Coordinated Selenoprotein Axis Restoration with Autonomic Gate Intervention in Chronically Stressed, Selenium-Insufficient Adults — Protocol for the SIK-STRESS Trial

This paper proposes the SIK-STRESS Trial: a 16-week randomized, double-blind, placebo-controlled trial in 160 adults with documented chronic stress (PSS-10 above 20) and selenium insufficiency (SELENOP below 4.0 mg/L), testing four arms: (A) Placebo; (B) Selenomethionine 200mcg plus CoQ10 200mg daily; (C) Full nutritional protocol (Arm B plus L-theanine, magnesium glycinate, NAC, sulforaphane); (D) Full nutritional protocol plus structured autonomic-circadian intervention (HRV biofeedback plus sleep hygiene protocol). Primary endpoints: SELENOP, plasma GPx activity, hair cortisol, and RMSSD. The trial is the first designed to test whether the Autonomic Gate mechanisms impair nutritional selenoprotein deployment sufficiently to warrant behavioral co-intervention.