Exploiting the Fractionation of Stable Isotopes in Biochemical Processes for Medical Diagnosis: A Narrative Review

Analysis of isotope distributions plays a crucial role in medical diagnostics. While radioactive and radiogenic isotopes - those that undergo or result from radioactive decay - are widely used, stable isotopes are less commonly applied despite their significant diagnostic potential. For example, calcium isotope ratio analysis is already commercially utilized for calcium loss and the early diagnosis of osteoporosis. Additionally, analyses of iron, copper, and zinc isotope ratios have been explored in various conditions, including hemochromatosis, Wilson's disease, cancer, Alzheimer's disease, and amyotrophic lateral sclerosis. Altered isotope ratios in these diseases are thought to reflect pathophysiologically relevant processes, making them promising biomarkers. This review provides a comprehensive overview of the current and potential applications of stable isotope analysis in medicine.