The Association Between Serum Leptin Levels and Post-Stroke Depression: A Retrospective Clinical Study

OBJECTIVE To investigate the question of whether serum leptin levels might be associated with post-stroke depression. METHODS We studied 130 patients who experienced a first episode of stroke of more than three months' duration, without any previous history of depression or speech disorders. Data were collected regarding the patient demographics, depressive mood (Diagnostic and Statistical Manual of Mental Disorders 4th edition [DSM-IV] criteria and Beck Depression Inventory) and serum leptin levels measured by an enzyme-linked immunosorbent assay (ELISA). In addition, the Korean version of Modified Barthel Index (K-MBI) and Korean version of Mini-Mental State Examination (K-MMSE) were used to assess the subjects' independence, in regard to the activities of daily living and cognition. A statistical analysis was performed to determine differences the serum leptin levels between patients with depression and those without depression, and to determine the difference in the MBI and K-MMSE scores between the groups separated according to the serum leptin levels. RESULTS Higher serum leptin levels were observed in patients with depression, compared with those without depression (38.5 ng/mL [range, 25.1-59.2 ng/mL] vs. 8.2 ng/mL [range, 4.9-17.8 ng/mL]; p<0.01. The serum leptin level showed an association with depression (odds ratio, 1.21; 95% confidence interval, 1.01-1.45; p=0.021). The K-MMSE and K-MBI improvement scores were lower, with statistical significance, in the group with the highest leptin level (>30 mg/dL), compared to the other two groups. CONCLUSION High serum leptin levels are associated with depression after stroke, and patients with elevated serum leptin levels were disadvantaged in regard to functional and cognitive outcomes.