Complications and Comorbidities in Individuals >80 Years with Diabetes: A Scoping Review

Background/Objectives: Diabetes mellitus is increasingly prevalent among adults aged over 80 years; however, this population remains substantially underrepresented in clinical research on diabetes complications. This scoping review synthesises current evidence on diabetes-related complications and comorbidities in this older age group (>80 years), reported prevalence, and key evidence gaps. Methods: A systematic search of MEDLINE, Embase, and Web of Science was conducted for studies published between 1992 and 2024 reporting diabetes-related complications in individuals aged ≥80 years. Two reviewers independently screened titles, abstracts, and full texts. Data were extracted and summarised using narrative synthesis, and descriptive statistics (SPSS v29) were conducted. Results: Fifty-one studies were included, comprising 17,630,083 individuals aged ≥80 years. Macrovascular complications were most frequently reported, followed by microvascular and peripheral outcomes. Hypertension was the most reported comorbidity. Macrovascular outcomes were assessed in over 17 million individuals, while microvascular complications were studied in fewer than 400,000. Only five studies focused exclusively on adults aged ≥80 years. Reporting was also limited by retrospective designs, heterogeneity in definitions, and frequent omission of key variables, including diabetes duration, HbA1c, frailty, and cognitive status. Conclusions: There is a critical mismatch between research focus and the complications most relevant to function and quality of life in older populations with diabetes. Easily measurable yet clinically impactful outcomes, such as retinopathy, neuropathy, nephropathy, and foot disease, remain under-investigated in this cohort. Standardised, age-stratified reporting that incorporates functional and geriatric domains is needed to inform person-centred care in this expanding population.