Ali Tomlin, Alan Sinclair

Diabetes is a growing public health issue, increasing in prevalence, eroding quality of life, and burdening health care systems. The complications of diabetes can be avoided or delayed by maintaining good glycemic control, which is achievable through self-management and, where necessary, medication. Older people with diabetes are at increased risk for cognitive impairment. This review aims to bring together current research that has investigated both cognition and diabetes self-management together. The Cumulative Index to Nursing and Allied Health (Cinahl), Excerpta Medica Database (Embase), Medical Literature Analysis and Retrieval System (Medline), and Psychological Information (PsychInfo) databases were searched. Studies were included if they featured older people with type 2 diabetes and had looked for associations between at least one distinct measure of cognition and at least one distinct measure of diabetes self-management. English language publications from the year 2000 were included. Cognitive measures of executive function, memory, and low scores on tests of global cognitive functioning showed significant correlations with multiple areas of diabetes self-management, including diabetes-specific numeracy ability, diabetes knowledge, insulin adjustment skills, ability to learn to perform insulin injections, worse adherence to medications, decreased frequency of self-care activities, missed appointments, decreased frequency of diabetes monitoring, and increased inaccuracies in reporting blood glucose monitoring. The nature of the subjects studied was quite variable in terms of their disease duration, previous medical histories, associated medical comorbidities, and educational level attained prior to being diagnosed with diabetes. The majority of studies were of an associational nature and not findings confirmed by repeat testing or by the effects of an intervention, neither were the majority of studies designed to give a view or conclusion on the clinical value or implications of the research. This only allows speculation of their importance. Most studies do not separate out the influence of aging itself in altering diabetes self-care behavior. We conclude that older people with type 2 diabetes are at increased risk for cognitive dysfunction. Changes in cognition may negatively affect diabetes self-management behaviors, influencing self-care outcomes. Age and depression may exacerbate any cognitive impairment.