Elevated triglyceride levels are associated with cognitive impairments among patients with major depressive disorder.

BACKGROUND: Cognitive deficits have been identified as one of core clinical symptoms of major depressive disorder (MDD). Accumulating evidence indicated that triglycerides (TG) might be associated with MDD and cognitive decline.

OBJECTIVE: This study examined whether patients with MDD had poorer cognitive functions than healthy controls, and further investigate whether TG levels were involved in MDD, and its cognitive impairments in a Han Chinese population.

METHOD: 115 patients with MDD and 119 healthy controls were enrolled. Cognitive functions were assessed by the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), and serum TG levels were examined using enzymatic colorimetry.

RESULTS: TG levels were higher in patients with MDD than healthy controls after controlling for the variables. Cognitive test scores were lower in patients with MDD than healthy controls except for visuospatial/constructional index after controlling for the variables. TG levels were negatively correlated with visuospatial/constructional score, delayed memory score and RBANS total score of MDD. Further multivariate regression analysis showed that TG levels were negatively associated with visuospatial/constructional score, attention score, delayed memory score and RBANS total score of MDD.

CONCLUSIONS: Our findings supported that serum TG levels might be involved in MDD, and play an important role in cognitive impairments of MDD, especially in delayed memory. Moreover, patients with MDD experienced greater cognitive impairments than healthy controls except for visuospatial/constructional index.