Type 2 Diabetes, Change in Depressive Symptoms Over Time, and Cerebral Small Vessel Disease: Longitudinal Data of the AGES-Reykjavik Study

Diabetes Care. 2020 Aug;43(8):1781-1787. doi: 10.2337/dc19-2437. Epub 2020 Jun 11.

Abstract

Objective: Type 2 diabetes has been associated with depression. However, the underlying pathophysiological mechanisms remain unknown. Cerebral small vessel disease, a consequence of diabetes, may lead to depression. Therefore, we evaluated whether cerebral small vessel disease mediates the association between type 2 diabetes and higher depressive symptoms.

Research design and methods: We used longitudinal data from the population-based Age, Gene/Environment Susceptibility (AGES)-Reykjavik Study, with examinations from 2002 to 2006 and 5 years later. Type 2 diabetes was defined as self-reported history of type 2 diabetes, use of blood glucose-lowering drugs, or fasting blood glucose level ≥7.0 mmol/L. Cerebral small vessel disease load was quantified in a composite score based on MRI-defined presence of high white matter hyperintensity volume, low total brain parenchyma volume, and subcortical infarcts, cerebral microbleeds, and large perivascular spaces. The 5-year change in the 15-item Geriatric Depression Scale score (GDS-15) was measured between baseline and follow-up.

Results: Included were 2,135 individuals without dementia and baseline depression (baseline age 74.5 [SD 4.6] years, 1,245 women [58.3%], and 197 [9.2%] with diabetes). The GDS-15 score increased 0.4 (SD 1.6) points over time. Baseline diabetes was associated with a greater increase in the GDS-15 score (β = 0.337; 95% CI 0.094; 0.579), adjusted for age, sex, education, and cardiovascular risk factors. Baseline cerebral small vessel disease and change of cerebral small vessel disease statistically significantly mediated a part of this association.

Conclusions: Type 2 diabetes is associated with a greater increase in depressive symptoms score over 5 years, and cerebral small vessel disease partly explains this association.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Brain / blood supply
  • Brain / diagnostic imaging
  • Brain / pathology
  • Cerebral Small Vessel Diseases / diagnosis
  • Cerebral Small Vessel Diseases / epidemiology*
  • Cohort Studies
  • Depression / epidemiology*
  • Diabetes Mellitus, Type 2 / epidemiology*
  • Female
  • Humans
  • Iceland / epidemiology
  • Longitudinal Studies
  • Magnetic Resonance Imaging
  • Male
  • Organ Size

Associated data

  • figshare/10.2337/figshare.12273077