Peripheral blood metabolic and inflammatory factors as biomarkers to ocular findings in diabetic macular edema.
OBJECTIVE
To study the association between peripheral blood metabolic and inflammatory factors and presence of diabetic macular edema (DME) and its related anatomic features in type 2 diabetic mellitus (T2DM) patients.


METHODS
Observational cross-sectional study on a proof of concept basis. Seventy-six T2DM included patients were divided based on the presence (n = 58) or absence of DME (n = 18) according to optical coherence tomography (OCT). Ultra-widefield fluorescein angiography (UWFA) was performed in DME patients. Fasting peripheral blood sample testing included glycemia, glycated hemoglobin, creatinin and lipid levels among others. Serum levels of a broad panel of cytokines and inflammatory mediators were also analysed. OCT findings included central subfoveal thickness, diffuse retinal thickness (DRT), cystoid macular edema (CME), serous retinal detachment and epirretinal membrane. UWFA items included pattern of DME, presence of peripheral retinal ischemia and enlarged foveal avascular zone (FAZ).


RESULTS
Metabolic and inflammatory factors did not statistically differ between groups. However, several inflammatory mediators did associate to certain ocular items of DME cases: IL-6 was significantly higher in patients with DRT (p = 0.044), IL-10 was decreased in patients with CME (p = 0.012), and higher IL-8 (p = 0.031) and VEGF levels (p = 0.031) were observed in patients with enlarged FAZ.


CONCLUSIONS
Inflammatory and metabolic peripheral blood factors in T2DM may not be differentially associated to DME when compared to non-DME cases. However, some OCT and UWFA features of DME such as DRT, CME and enlarged FAZ may be associated to certain systemic inflammatory mediators.
Institut Clínic d'Oftalmologia (ICOF), Hospital Clínic, Barcelona, Spain.|August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain.
Marc
M
Figueras-Roca
August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain.
Blanca
B
Molins
Institut Clínic d'Oftalmologia (ICOF), Hospital Clínic, Barcelona, Spain.|August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain.
Anna
A
Sala-Puigdollers
Institut Clínic d'Oftalmologia (ICOF), Hospital Clínic, Barcelona, Spain.|August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain.
Jessica
J
Matas
Department of Endocrinology, Hospital Clínic, Barcelona, Spain.
Irene
I
Vinagre
Medical Statistics Core Facility, IDIBAPS, Barcelona, Spain.|Biostatistics Unit, Faculty of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain.
José
J
Ríos
Institut Clínic d'Oftalmologia (ICOF), Hospital Clínic, Barcelona, Spain.|August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain.
Alfredo
A
Adán
D000368:Aged; D015415:Biomarkers / Q000097:blood; D003430:Cross-Sectional Studies; D016207:Cytokines / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000150:complications*; D003930:Diabetic Retinopathy / Q000097:blood* / Q000000981:diagnostic imaging; D005260:Female; D005451:Fluorescein Angiography; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood; D008269:Macular Edema / Q000097:blood* / Q000150:complications* / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D041623:Tomography, Optical Coherence
D015415:Biomarkers; D016207:Cytokines; D018836:Inflammation Mediators