title: Chronic depression symptoms and salivary NOx are associated with retinal vascular dysregulation: The SABPA study.
abstract: Depression has been associated with impaired nitric oxide (NO)-mediated vasodilation and vascular dysregulation (VD). Whether depression and NO levels will disturb retinal haemodynamics is not clear.
  
  
  
  Associations between the retinal vasculature, diastolic ocular perfusion pressure (DOPP) as measure of hypoperfusion, NO metabolites (NOx) and depression symptoms were assessed. Chronic VD risk markers [depression symptoms (Patient Health Questionnaire/PHQ-9 ≥ 10) and 24 h pulse pressure] were determined in a bi-ethnic cohort (n = 313; 48.6 ± 9 years; 53.9% men). At 3 year follow-up, retinal vessel calibre and retinopathy signs were quantified from digital images. Salivary NOx was obtained pre- and post-flicker light-induced provocation (FLIP). DOPP was defined as diastolic blood pressure minus intraocular pressure.
  
  
  
  Chronic VD risk was evident in Blacks opposed to acute risk in Whites (P < 0.05). At follow-up, retinopathy (Blacks 60.4%/Whites 39.6%), lower pre-FLIP (μM) and higher post-FLIP NOx (changes from baseline, %), arteriolar narrowing and wider venular calibre values were evident in Blacks compared to Whites, independent of confounders. A wider venular calibre, an index of stroke risk, was associated with chronic depression symptoms [cut point 248 MU: Area under the curve 0.61 (95% CI: 0.51, 0.72); 71% sensitivity; 55% specificity] as well as with hypoperfusion in the Blacks. In this group, arteriolar narrowing was associated with hypoperfusion; and attenuated arteriolar dilation with increased post-FLIP NOx responses.
  
  
  
  Chronic depression symptoms may alter NO regulation and facilitate VD. NO-mediated vasoconstriction presumably impeded perfusion, retinal haemodynamics and -remodelling; potentiating stroke risk in Blacks.
authors.affiliation: Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa. Electronic address: leone.malan@nwu.ac.za.
authors.forename: Leoné
authors.initials: L
authors.lastname: Malan
authors.affiliation: Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa; National Centre for Sport and Exercise Medicine, Loughborough University, Leicestershire, United Kingdom.
authors.forename: Mark
authors.initials: M
authors.lastname: Hamer
authors.affiliation: Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa; Department Neurology, Inselspital, Bern University Hospital, University of Bern, Switzerland.
authors.forename: Roland
authors.initials: R
authors.lastname: von Känel
authors.affiliation: School of Medicine and Pharmacology-Royal Perth Hospital Unit, Faculty of Medicine, Dentistry & Health Sciences, University Western Australia, Australia.
authors.forename: Markus P
authors.initials: MP
authors.lastname: Schlaich
authors.affiliation: Autonomic and Neuroendocrinological Laboratory Dresden, University Hospital Carl Gustav Carus, Technische Universität Dresden, Germany.
authors.forename: Manja
authors.initials: M
authors.lastname: Reimann
authors.affiliation: Department of Psychiatry and School of Nursing, McGill University, Department of Psychiatry, University of Montreal, Centre de recherche Centre hospitalier de l'Université de Montréal and Montreal Heart Institute Research Center, Canada.
authors.forename: Nancy
authors.initials: N
authors.lastname: Frasure-Smith
authors.affiliation: Baker IDI Heart & Diabetes Institute and Central Clinical School, Monash University, Melbourne, Australia.
authors.forename: Gavin W
authors.initials: GW
authors.lastname: Lambert
authors.affiliation: Imedos Systems UG, Jena, Germany.
authors.forename: Walthard
authors.initials: W
authors.lastname: Vilser
authors.affiliation: Center of Excellence for Pharmaceutical Sciences, Division of Pharmacology, School for Pharmacy, North-West University, Potchefstroom Campus, South Africa.
authors.forename: Brian H
authors.initials: BH
authors.lastname: Harvey
authors.affiliation: Statistical Consultation Services, North-West University, Potchefstroom, South Africa.
authors.forename: Faans
authors.initials: F
authors.lastname: Steyn
authors.affiliation: Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa.
authors.forename: Nico T
authors.initials: NT
authors.lastname: Malan
mesh_terms: D044383:Black People; D001794:Blood Pressure / Q000502:physiology; D003863:Depression / Q000150:complications / Q000208:ethnology / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D009566:Nitrates / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism; D012164:Retinal Diseases / Q000208:ethnology / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D012171:Retinal Vessels / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D012463:Saliva / Q000378:metabolism*; D020521:Stroke / Q000208:ethnology / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology; D066253:Vascular Remodeling; D044465:White People
chemical_list: D009566:Nitrates; D009573:Nitrites; D009569:Nitric Oxide
keywords: Depression; Ethnicity; Hypoperfusion; NOx; Pulse pressure; Retina