New IGF-1 reference values established for French population, standardizing multiple assay kits

Accurate interpretation of Insulin-like Growth Factor 1 (IGF-1) levels is crucial for diagnosing and monitoring various conditions, including growth hormone deficiency and acromegaly. However, a significant challenge in clinical practice is the lack of standardized IGF-1 measurements; different assay kits yield widely disparate results for the same sample. This variability complicates longitudinal patient monitoring and cross-laboratory comparisons, necessitating the establishment of robust, assay-specific reference values that also account for individual factors like age and nutritional status.

This study aims to establish comprehensive normative data for IGF-1 concentrations in the general French population. Researchers plan to recruit around 100 subjects for each decade age range, ensuring broad representation across all age groups. Subjects with medical conditions or medications known to affect IGF-1 levels will be excluded to maintain data purity. The study will perform IGF-1 measurements using all available assay kits currently employed in French clinical laboratories. The primary objective is to define IGF-1 reference ranges (specifically, the 2.5 to 97.5 percentiles) for each assay, reporting results in both mass units and standardized SD scores.

This abstract outlines the methodology and objectives for establishing comprehensive IGF-1 reference values rather than presenting actual findings. The study's core aim is to generate robust normative data, including the range (2.5 to 97.5 percentiles), which will be reported in both mass units and SD scores. This approach is designed to allow for accurate longitudinal comparison of IGF-1 concentrations in individual patients, even when different assay kits are utilized over time. The researchers plan to address the current issue of assay-specific variability in IGF-1 measurements across French laboratories, which currently yield disparate results for identical samples. The objective is to establish these reference values for all available IGF-1 assay kits to ensure broad applicability and significantly improve the accuracy of clinical interpretation and patient management.

The core objective is to establish robust IGF-1 normative data, spanning 2.5 to 97.5 percentiles, for all common assay kits, enabling consistent patient monitoring despite assay changes.