To examine the correlation between serum insulin-like growth factor 1 (IGF-1) and osteoporosis (OP) in Parkinson's disease (PD).We retrospectively analyzed clinical data from 105 PD patients (PD group) and 78 individuals in the health examination group (HC group). We compared general clinical data and serum IGF-1 levels between the two groups. PD patients were further categorized into PD with OP (50 cases) and PD without OP (55 cases) based on dual-energy X-ray absorptiometry (DXA) results for bone density. We compared general clinical data and serum IGF-1 levels between these two subgroups. Pearson correlation coefficient analysis was conducted to assess the relationship between serum IGF-1 levels and bone density at the lumbar spine and left femoral neck. Multifactorial logistic regression analysis was performed to identify risk factors for PD with OP.Serum IGF-1 levels were significantly lower in the PD group compared to the HC group (P < 0.05). Pearson correlation analysis revealed a positive association between serum IGF-1 levels and both lumbar spine and left femoral neck bone densities (r = 0.653, P < 0.001; r = 0.625, P < 0.001). Multivariate logistic regression analysis identified decreased serum IGF-1 levels, lower uric acid levels, and higher H-Y stage as risk factors for PD with OP (P < 0.05).Reduced levels of serum IGF-1, uric acid, and an increased H-Y stage are closely linked to osteoporosis in PD. Elevating serum levels of IGF-1 and uric acid may potentially offer therapeutic avenues for PD with osteoporosis.© 2024. Fondazione Società Italiana di Neurologia.