title: Neutrophil gelatinase-associated lipocalin: a novel inflammatory marker associated with late-life depression.
abstract: OBJECTIVE
  Systemic low graded inflammation has been identified as a possible biological pathway in late-life depression. Identification of inflammatory markers and their association with characteristics of depression is essential with the aim to improve diagnosis and therapeutic approaches. This study examines the determinants of plasma Neutrophil Gelatinase-Associated Lipocalin (NGAL), which is selectively triggered by TNFα receptor 1 signaling within the central nervous system, and its association with late-life depressive disorder.
  
  
  METHODS
  Baseline data were obtained from a well-characterized prospective cohort study of 350 depressed and 129 non-depressed older persons (≥60years). Past 6month diagnosis of major depressive disorder (MDD) according to DSM-IV-TR criteria was assessed with the Composite International Diagnostic Interview (CIDI 2.0). Potential determinants of plasma NGAL included sociodemographic characteristics, lifestyle and psychiatric and physical comorbidity.
  
  
  RESULTS
  Plasma NGAL concentrations were significantly associated with age, male gender, smoking and waist circumference. Adjusted for these determinants, depressed patients had significantly higher NGAL plasma levels compared to non-depressed comparison group. Depressed patients who did not meet full criteria for MDD in the month before sampling (partially remitted) had lower plasma NGAL levels compared with those who did. Subjects with a recurrent depression had higher plasma NGAL levels compared to those with a first episode. NGAL levels were neither related with specific symptom profiles of depression nor with antidepressant drug use.
  
  
  CONCLUSIONS
  Adjusted for confounders, NGAL plasma levels are increased in depressed older persons, without any effect of antidepressant medication and age of onset.
authors.affiliation: Department of Molecular Neurobiology, University of Groningen, Groningen, The Netherlands; University Center of Psychiatry & Interdisciplinary Center of Psychopathology of Emotion Regulation, University of Groningen, University Medical Center Groningen, 9700 RB Groningen, The Netherlands; Department of Neurology and Alzheimer Research Center, University of Groningen, University Medical Center Groningen, The Netherlands. Electronic address: p.j.w.naude@umcg.nl.
authors.forename: P J W
authors.initials: PJ
authors.lastname: Naudé
authors.forename: U L M
authors.initials: UL
authors.lastname: Eisel
authors.forename: H C
authors.initials: HC
authors.lastname: Comijs
authors.forename: N A
authors.initials: NA
authors.lastname: Groenewold
authors.forename: P P
authors.initials: PP
authors.lastname: De Deyn
authors.forename: F J
authors.initials: FJ
authors.lastname: Bosker
authors.forename: P G M
authors.initials: PG
authors.lastname: Luiten
authors.forename: J A
authors.initials: JA
authors.lastname: den Boer
authors.forename: R C
authors.initials: RC
authors.lastname: Oude Voshaar
mesh_terms: D000209:Acute-Phase Proteins; D000368:Aged; D000928:Antidepressive Agents / Q000008:administration & dosage; D015415:Biomarkers / Q000097:blood; D002908:Chronic Disease; D015897:Comorbidity; D003863:Depression / Q000097:blood* / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology; D003866:Depressive Disorder / Q000097:blood* / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology; D003865:Major Depressive Disorder / Q000097:blood / Q000175:diagnosis; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007249:Inflammation; D007406:Interview, Psychological; D008019:Life Style; D000071068:Lipocalin-2; D054834:Lipocalins / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D011446:Prospective Studies; D011518:Proto-Oncogene Proteins / Q000097:blood*; D012008:Recurrence
chemical_list: D000209:Acute-Phase Proteins; D000928:Antidepressive Agents; D015415:Biomarkers; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins
keywords: Aging; Inflammation; Late-life depression; Lipocalin 2; NESDO