Acromegaly: Biochemical diagnosis.

The biochemical diagnosis of acromegaly presents significant challenges due to the dynamic nature of growth hormone (GH) secretion, assay variability, and the influence of both physiological and pathological factors. Measurement of serum insulin-like growth factor 1 (IGF-1) remains the cornerstone for diagnosis and disease monitoring, as it provides a stable indication of integrated GH secretion. However, discordance between GH and IGF-1 levels can occur in up to 30 percent of cases, complicating clinical decision-making and requiring an assay-aware, and context-sensitive approach. The oral glucose tolerance test (OGTT) serves as a critical adjunct in ambiguous cases. Analytical variability, physiological pulsatility, comorbidities, such as obesity, diabetes, hepatic and renal dysfunction, and methodological interferences can all contribute to discordant results. Advanced analytical techniques, including mass spectrometry-based IGF-1 assays, hold promise for improving diagnostic accuracy. Future directions emphasise assay standardisation and integration of multimodal biomarkers to enhance clinical decision-making. A multidisciplinary, patient-centred approach, that combines clinical expertise, robust biochemical evaluation, and innovative technologies is essential for optimising outcomes in acromegaly.