Finding Early Biomarkers to Prevent Unfavorable Long-Term Health Outcomes after Premature Adrenarche: A Multicenter Prospective Cohort Study Protocol.

Introduction: Adrenarche is a prepubertal developmental phase in humans characterized by increasing levels of adrenal androgens in circulation. While its regulation and biological significance remain poorly understood, the earlier onset of adrenarche - referred to as premature adrenarche (PA) - raises concerns about potential long-term health risks, including metabolic syndrome and polycystic ovary syndrome. Our study aimed to elucidate the regulatory mechanisms underlying adrenarche and PA, specifically investigating whether PA represents a benign variation of normal development, or a disorder associated with increased risks of unfavorable metabolic and reproductive outcomes in adulthood.

Methods: This study employs a longitudinal design to track a well-characterized cohort of children with PA alongside age-matched healthy controls, following them from adrenarche through puberty into early adulthood. Conducted across two independent research centers in Kuopio, Finland, and Bern, Switzerland, the study involves detailed phenotypic assessments, including comprehensive medical histories and body composition analyses. Biological samples undergo multi-omics profiling - encompassing transcriptomics and metabolomics - using advanced techniques such as liquid and gas chromatography tandem-mass spectrometry and RNA sequencing. This integrated approach aims to identify biomarkers predictive of adverse health outcomes in PA, with candidate biomarkers and regulatory factors further validated through in vitro adrenal cell model studies.

Conclusion: This study provides the first comprehensive, longitudinal comparison of PA and healthy controls across critical developmental milestones. By elucidating the molecular factors that regulate the maturation of the zona reticularis, it seeks to resolve the longstanding mystery of adrenarche. Furthermore, by differentiating benign developmental variations from PA cases linked with long-term health risks, the findings could refine current diagnostic criteria and enable early identification of children at risk. Ultimately, this research paves the way for more accurate diagnoses, targeted interventions, and improved long-term health outcomes.