A Systematic Review and Delphi Study to Ascertain Common Risk Factors for Type 2 Diabetes Mellitus and Dementia and Brain-Related Complications of Diabetes in Adults

Abstract

Objectives: Both type 2 diabetes (T2DM) and dementia have multifactorial etiologies. Both are associated with aging and have well-recognized lifestyle, cardiovascular and psychosocial risk factors. However, uncertainty exists in the literature with regard to: 1) the potentially modifiable risk factors common to both dementia and T2DM, and 2) the risk of brain-related complications in those with established diabetes. In this study, we address this uncertainty and inform design of a survey questionnaire to assess knowledge about diabetes and brain health among at-risk groups.

Methods: This investigation consisted of a mixed-methods approach, including a Delphi consensus study preceded by a systematic literature review. The review was conducted using MEDLINE, EMBASE and Cochrane Library databases. A 2-round online Delphi study, informed by the review, invited international experts to rate their agreement with proposed risk factors and complications.

Results: Of 7,337 abstracts retrieved, 13 were included in the final review. Among 46 international experts invited to take part in the Delphi study, 14 (32%) responded. In the Delphi study, hypertension, obesity, physical inactivity and heavy alcohol consumption reached consensus as risk factors common to both T2DM and dementia. Proposed brain-related diabetes complications, depression and dementia were also identified.

Conclusions: Results revealed expert consensus and literature review agreement on a number of common modifiable risk factors for T2DM and dementia, as well as agreement on brain-related complications of diabetes. A number of other proposed shared risk factors did not reach consensus agreement, suggesting a need for more high-quality studies to add to the evidence base.

Keywords: complications du diabète; dementia; diabetes; diabetes complications; diabète; diabète sucré de type 2; démence; primary prevention; prévention primaire; prévention secondaire; secondary prevention; type 2 diabetes mellitus.