High serum levels of leptin are associated with post-stroke depression

Depression is a frequent mood disorder that affects around 33% of stroke patients and has been associated with both poorer outcome and increased mortality. Our aim was to test the possible association between inflammatory and neurotrophic molecular markers and the development of post-stroke depression.

We studied 134 patients with a first episode of ischemic stroke without previous history of depression or speech disorders. We screened for the existence of major depression symptoms in accordance with DSM-IV criteria and a Yesavage Geriatric Depression Scale (GDS) score >11 at discharge and 1 month after stroke. At these times, serum levels of molecular markers of inflammation [interleukin (IL)-1beta, IL-6, intracellular adhesion molecule 1 (ICAM-1), tumor necrosis factor (TNF)-alpha, leptin and high-sensitivity C-reactive protein (hs-CRP)] and neurotrophic factors [brain-derived neurotrophic factor (BDNF)] were measured by enzyme-linked immunosorbent assay (ELISA).

Twenty-five patients (18.7%) were diagnosed as having major depression at discharge. Out of 104 patients who completed the follow-up period, 23 were depressed at 1 month (22.1%). Patients with major depression showed higher serum leptin levels at discharge [43.4 (23.4-60.2) v. 6.4 (3.7-16.8) ng/ml, p<0.001] and at 1 month after stroke [46.2 (34.0-117.7) v. 6.4 (3.4-12.2) ng/ml, p<0.001). Serum levels of leptin >20.7 ng/ml were independently associated with post-stroke depression [odds ratio (OR) 16.4, 95% confidence interval (CI) 5.2-51.5, p<0.0001]. Leptin levels were even higher in the eight patients who developed depression after discharge [114.6 (87.6-120.2) v. 7.2 (3.6-13.6) ng/ml, p<0.0001].

Serum leptin levels at discharge are found to be associated with post-stroke depression and may predict its development during the next month.