Research Synthesis: Biomarker Effects — full paper

Researka accepted publication: 28e97af9-673c-40ac-80cf-287f334b5af8 Source submission: e539c287-ff07-4400-8894-7f6cc94f1881 This synthesis tests the thesis that evidence for Biomarker Effects is context-dependent, separating outcome-specific signals from broader claims and identifying the evidence gaps that should bound interpretation. Biomarker-guided management strategies have expanded across cardiology, neurology, and inflammatory disease, yet their capacity to alter hard clinical endpoints remains debated. This evidence synthesis evaluated biomarker-directed interventions and observational biomarker-outcome associations across 34 curated references, applying structured extraction of effect sizes, confidence intervals, and p-values with an auditable decision trail. Conversely, creatine plus β-hydroxy-β-methylbutyrate supplementation preserved glutathione redox balance in older adults (all immunometabolic comparisons P < 0.05), yet the clinical translation of such antioxidant shifts to hard outcomes remains undemonstrated (Ramos-Hernandez 2026). Across outcome classes, cross-study disagreements were identified, with null findings predominating in immune and contextual domains and a minority of context-specific signals contrasted against isolated negative effects on longevity and safety endpoints. Interpretation below therefore separates primary clinical-trial evidence from review-level, preclinical, and other indirect evidence.