title: Lower Hemoglobin Concentration Is Associated with Retinal Ischemia and the Severity of Diabetic Retinopathy in Type 2 Diabetes.
abstract: Aims. To assess the association of blood oxygen-transport capacity variables with the prevalence of diabetic retinopathy (DR), retinal ischemia, and macular oedema in patients with type 2 diabetes mellitus (T2DM). Methods. Cross-sectional, case-control study (N = 312) with T2DM: 153 individuals with DR and 159 individuals with no DR. Participants were classified according to the severity of DR and the presence of retinal ischemia or macular oedema. Hematological variables were collected by standardized methods. Three logistic models were adjusted to ascertain the association between hematologic variables with the severity of DR and the presence of retinal ischemia or macular oedema. Results. Individuals with severe DR showed significantly lower hemoglobin, hematocrit, and erythrocyte levels compared with those with mild disease and in individuals with retinal ischemia and macular oedema compared with those without these disorders. Hemoglobin was the only factor that showed a significant inverse association with the severity of DR [beta-coefficient = -0.52, P value = 0.003] and retinal ischemia [beta-coefficient = -0.49, P value = 0.001]. Lower erythrocyte level showed a marginally significant association with macular oedema [beta-coefficient = -0.86, P value = 0.055]. Conclusions. In patients with DR, low blood oxygen-transport capacity was associated with more severe DR and the presence of retinal ischemia. Low hemoglobin levels may have a key role in the development and progression of DR.
authors.affiliation: Department of Ophthalmology, University Hospital Arnau de Vilanova, 25198 Lleida, Spain.
authors.forename: Alicia
authors.initials: A
authors.lastname: Traveset
authors.affiliation: Department of Endocrinology and Nutrition, University Hospital Arnau de Vilanova, 25198 Lleida, Spain; Institut de Recerca Biomedica de Lleida, University of Lleida, 25198 Lleida, Spain.
authors.forename: Esther
authors.initials: E
authors.lastname: Rubinat
authors.affiliation: Department of Endocrinology and Nutrition, Institut d'Investigacions Biomediques August Pi Suñer, CIBER de Obesidad y Nutrición, Hospital Clinic, 08036 Barcelona, Spain.
authors.forename: Emilio
authors.initials: E
authors.lastname: Ortega
authors.affiliation: Institut de Recerca Biomedica de Lleida, University of Lleida, 25198 Lleida, Spain.
authors.forename: Nuria
authors.initials: N
authors.lastname: Alcubierre
authors.affiliation: Department of Optometry, University Hospital Arnau de Vilanova, 25198 Lleida, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Vazquez
authors.affiliation: Department of Endocrinology and Nutrition, University Hospital Arnau de Vilanova, 25198 Lleida, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Hernández
authors.affiliation: Department of Ophthalmology, University Hospital Arnau de Vilanova, 25198 Lleida, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Jurjo
authors.affiliation: Department of Ophthalmology, University Hospital Arnau de Vilanova, 25198 Lleida, Spain.
authors.forename: Ramon
authors.initials: R
authors.lastname: Espinet
authors.affiliation: Department of Ophthalmology, University Hospital Arnau de Vilanova, 25198 Lleida, Spain.
authors.forename: Juan Antonio
authors.initials: JA
authors.lastname: Ezpeleta
authors.affiliation: Department of Endocrinology and Nutrition, CIBER of Diabetes and Associated Metabolic Diseases (CIBERDEM), Health Sciences Research Institute and University Hospital Germans Trias i Pujol, 08916 Badalona, Spain.
authors.forename: Didac
authors.initials: D
authors.lastname: Mauricio
mesh_terms: D000328:Adult; D000368:Aged; D000740:Anemia / Q000453:epidemiology* / Q000378:metabolism; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000378:metabolism*; D003930:Diabetic Retinopathy / Q000453:epidemiology* / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D004906:Erythrocyte Count; D005260:Female; D006400:Hematocrit; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D007511:Ischemia / Q000453:epidemiology* / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D008269:Macular Edema / Q000453:epidemiology* / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012171:Retinal Vessels; D012720:Severity of Illness Index
chemical_list: D006454:Hemoglobins