Retinal vascular fractals predict long-term microvascular complications in type 1 diabetes mellitus: the Danish Cohort of Pediatric Diabetes 1987 (DCPD1987)

• Published in: Diabetologia 2014-10, Vol.57 (10), p.2215-2221
• Main Authors: Broe, Rebecca, Rasmussen, Malin L., Frydkjaer-Olsen, Ulrik, Olsen, Birthe S., Mortensen, Henrik B., Peto, Tunde, Grauslund, Jakob
• Format: Article
• Language: English
• Subjects: Adult; Biological and medical sciences; Biomarkers; Biomarkers - metabolism; Diabetes; Diabetes Complications - etiology; Diabetes Complications - physiopathology; Diabetes Mellitus, Type 1 - complications; Diabetes Mellitus, Type 1 - physiopathology; Diabetes. Impaired glucose tolerance; Diabetic neuropathy; Diabetic retinopathy; Diabetic Retinopathy - etiology; Diabetic Retinopathy - physiopathology; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Etiopathogenesis. Screening. Investigations. Target tissue resistance; Eye and associated structures. Visual pathways and centers. Vision; Female; Fractals; Fundamental and applied biological sciences. Psychology; Human Physiology; Humans; Internal Medicine; Male; Medical sciences; Medicine; Medicine & Public Health; Metabolic Diseases; Ophthalmology; Pediatrics; Retinal Vessels - pathology; Retinal Vessels - physiopathology; Vertebrates: nervous system and sense organs; Young Adult
• ISSN: 0012-186X; 1432-0428
• DOI: 10.1007/s00125-014-3317-6

Aims/hypothesis Fractal analysis of the retinal vasculature provides a global measure of the complexity and density of retinal vessels summarised as a single variable: the fractal dimension. We investigated fractal dimensions as long-term predictors of microvasculopathy in type 1 diabetes. Methods We included 180 patients with type 1 diabetes in a 16 year follow-up study. In baseline retinal photographs (from 1995), all vessels in a zone 0.5–2.0 disc diameters from the disc margin were traced using Singapore Institute Vessel Assessment-Fractal image analysis software. Artefacts were removed by a certified grader, and fractal dimensions were calculated using the box-counting method. At follow-up (in 2011), diabetic neuropathy, nephropathy and proliferative retinopathy were assessed and related to baseline fractal dimensions in multiple regressions adjusted for sex and baseline age, diabetes duration, HbA 1c , BP, BMI, vibration perception threshold, albuminuria, retinopathy and vessel diameters. Results Mean baseline age and diabetes duration were 21.0 and 13.4 years, respectively, and of patients 50.0% were males. The mean fractal dimension was 1.3817. The 16 year incidences of neuropathy, nephropathy and proliferative retinopathy were 10.8%, 8.0% and 27.9%, respectively. Multiple regression analyses showed a lower fractal dimension to significantly predict incident neuropathy (OR 1.17 per 0.01 fractal dimension decrease [95% CI 1.01, 1.36]), nephropathy (OR 1.40 per 0.01 fractal dimension decrease [95% CI 1.10, 1.79]) and proliferative retinopathy (OR 1.22 per 0.01 fractal dimension decrease [95% CI 1.09, 1.37]). Conclusions/interpretation The retinal vascular fractal dimension is a shared biomarker of diabetic microvasculopathy, thus indicating a possible common pathogenic pathway. Retinal fractal analysis therefore is a potential tool for risk stratification in type 1 diabetes.