Plasma Biomarkers of Neurodegeneration and Neuroinflammation among Middle- Aged Adults in Western India: Implications of Racial and Geographical Variability

Background Neurodegenerative disorders (NDs) are progressive conditions associated with neuronal loss, cognitive decline, and high global morbidity and mortality. Blood-based biomarkers such as amyloid-β (Aβ1–42), tau, α-synuclein, brain-derived neurotrophic factor (BDNF), and glial fibrillary acidic protein (GFAP) hold promise for early detection and monitoring. This study evaluated plasma levels of key neurodegenerative biomarkers in an apparently healthy middle-aged Indian cohort and compared them with global datasets to explore potential racial, genetic, and environmental influences. Methods A cross-sectional community-based study recruited 405 participants (40–60 years, both sexes) from Ahmedabad district, western India, following strict inclusion and exclusion criteria. Demographic and clinical parameters were recorded, and venous blood samples were collected under aseptic conditions. Biomarkers (Aβ1–42, total tau, α-synuclein, BDNF, GFAP) were quantified using high-sensitivity sandwich ELISA. Statistical analysis included t-tests, median comparisons, and age- and sex-stratified analyses. Results Median plasma concentrations were: Aβ1–42 (18.95 pg/mL), total tau (84.38 pg/mL), α-synuclein (804.51 pg/mL), BDNF (2221.98 pg/mL), and GFAP (98.33 pg/mL). Relatively older participants (aged 51–60 years) demonstrated elevated biomarker levels compared to younger counterparts. Comparison with international datasets revealed marked inter-regional variability, suggesting potential genetic, racial, and environmental influences. Conclusion The study describes the levels of plasma neurodegenerative biomarkers in a community of Indian population, further emphasizing the variations in the levels of these markers among healthy adults across the globe. These findings underscore the importance of accounting for racial and geographical differences when interpreting biomarker data and call for longitudinal studies to establish population-specific reference ranges.