Objective: In order to examine a possible role of serum heart-fatty acid binding protein (H-FABP) in patients with Lewy body disease, we measured serum levels of H-FABP in patients with dementia with Lewy bodies (DLB), Parkinson's disease (PD), and Alzheimer's disease (AD).
Methods: Serum levels of H-FABP were measured using a solid-phase enzyme-linked immunoassay. Iodine-123 metaiodobenzylguanidine ((123)I-MIBG) cardiac scintigraphy was performed on each patient and the heart to mediastinum (H/M) ratio was calculated. Receiver operating characteristic (ROC) analysis was used to calculate the optimal cutoff values of the H-FABP between DLB and AD patients. Independent predictive variables for serum H-FABP levels were analyzed using multivariate regression analysis.
Results: Serum levels of H-FABP were significantly higher in DLB patients and PD patients than in AD patients. H/M ratios of the DLB and PD patients were significantly lower than those of AD patients. The diagnostic value of the serum H-FABP levels between AD and DLB patients was inferior to that of the delayed H/M ratio of (123)I-MIBG cardiac scintigraphy. Multivariate regression analysis revealed that the delayed H/M ratio predicted serum H-FABP levels in the PD patients.
Conclusions: Examination of serum H-FABP levels did not allow discrimination between DLB and AD patients. Cardiac sympathetic nerve dysfunction may be associated with elevation of serum H-FABP in Lewy body disease patients.