Atrophy of the optic chiasm is associated with microvascular diabetic complications in type 1 diabetes

Front Endocrinol (Lausanne). 2023 May 30:14:1134530. doi: 10.3389/fendo.2023.1134530. eCollection 2023.

Abstract

Introduction: Diabetic neuropathy and diabetic eye disease are well known complications of type 1 diabetes. We hypothesized that chronic hyperglycemia also damages the optic tract, which can be measured using routine magnetic resonance imaging. Our aim was to compare morphological differences in the optic tract between individuals with type 1 diabetes and healthy control subjects. Associations between optic tract atrophy and metabolic measures, cerebrovascular and microvascular diabetic complications were further studied among individuals with type 1 diabetes.

Methods: We included 188 subjects with type 1 diabetes and 30 healthy controls, all recruited as part of the Finnish Diabetic Nephropathy Study. All participants underwent a clinical examination, biochemical work-up, and brain magnetic resonance imaging (MRI). Two different raters manually measured the optic tract.

Results: The coronal area of the optic chiasm was smaller among those with type 1 diabetes compared to non-diabetic controls (median area 24.7 [21.0-28.5] vs 30.0 [26.7-33.3] mm2, p<0.001). In participants with type 1 diabetes, a smaller chiasmatic area was associated with duration of diabetes, glycated hemoglobin, and body mass index. Diabetic eye disease, kidney disease, neuropathy and the presence of cerebral microbleeds (CMBs) in brain MRI were associated with smaller chiasmatic size (p<0.05 for all).

Conclusion: Individuals with type 1 diabetes had smaller optic chiasms than healthy controls, suggesting that diabetic neurodegenerative changes extend to the optic nerve tract. This hypothesis was further supported by the association of smaller chiasm with chronic hyperglycemia, duration of diabetes, diabetic microvascular complications, as well as and CMBs in individuals with type 1 diabetes.

Keywords: cerebral microbleeds; cerebrovascular disease; diabetic neuropathy; diabetic retinopathy; magnetic resonance imaging; neuroradiology; optic chiasm; type 1 diabetes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Atrophy
  • Chronic Disease
  • Diabetes Complications* / pathology
  • Diabetes Mellitus, Type 1* / complications
  • Diabetes Mellitus, Type 1* / pathology
  • Humans
  • Hyperglycemia* / pathology
  • Optic Chiasm / pathology

Grants and funding

The FinnDiane Study was supported by grants from the Folkhälsan Research Foundation, Academy of Finland, Wilhelm and Else Stockmann Foundation, Liv och Hälsa Society, the Medical Society of Finland, Novo Nordisk Foundation, Päivikki and Sakari Sohlberg Foundation, and by an EVO governmental grant. DG was supported by Wilhelm and Else Stockmann Foundation, Liv och Hälsa Society, Medical Society of Finland (Finska Läkaresällskapet), Dorothea Olivia, Karl Walter and Jarl Walter Perklén’s Foundation, Päivikki and Sakari Sohlberg Foundation, Sigrid Juselius Foundation, Minerva Foundation Institute for Medical Research, the University of Helsinki (Clinical Researcher stint), and the Academy of Finland (UAK1021MRI). None of the funding bodies had any role in the study design, collection, analysis, or interpretation of data. Nor had the funding bodies any role in the writing of the report, nor in the decision to submit the paper for publication. Funding for volumetric analysis was provided by the FinnDiane research group.