NGAL and other markers of inflammation as competitive or complementary markers for depressive symptom dimensions in heart failure

Objectives. Neutrophil gelatinase-associated lipocalin (NGAL) is an inflammatory marker associated with the pathophysiology of heart failure (HF), the psychopathology of depression and the co-existing symptoms of depression in HF patients. The aim of this study is to determine whether the association of serum NGAL levels with depressive symptoms dimensions in HF is independent of well-known inflammatory markers. Methods. Serum NGAL, high sensitive C-reactive protein (hsCRP), tumour necrosis factor-α (TNF-α), its two soluble receptors; sTNFR1, sTNFR2, Interleukin-6 (IL-6) and leukocytes were measured in 104 patients with HF at baseline and 12 months. Depressive symptoms were evaluated using the Beck Depression Inventory (BDI) at both timepoints. Correlations between NGAL and inflammatory markers and depressive symptoms dimensions were determined. The effect of hsCRP, IL-6, TNF-α, sTNFR1, sTNFR2 and leukocytes on the association of NGAL with depressive symptoms was determined and adjusted for time, demographics, cardiac disease severity, and kidney function. Results. NGAL levels were significantly correlated with hsCRP, TNF-α, sTNFR1, sTNFR2 and leukocytes. NGAL was significantly associated with somatic depressive symptoms, independent of abovementioned markers. Conclusions. Serum NGAL is an independent inflammatory marker for somatic depressive symptoms in HF and may function as an immunopathogen linking somatic symptoms of depression to HF. Keywords:: Lipocalin 2, cognitive and somatic depressive symptoms, tumor necrosis factor alpha, interleukin-6, C reactive protei