Pathophysiology and Treatment of Type 1 Diabetes in Older Adults

This article highlights how age and type 1 diabetes interact to shape clinical onset and treatment, emphasizing the need for tailored strategies in classifying and managing type 1 diabetes across the lifespan, particularly in later life. This article represents an expert perspective based on selected literature. In considering type 1 diabetes in adults, distinction is needed between incident cases, where biological age influences underlying pathophysiology, and prevalent cases, capturing both adult-onset type 1 diabetes and long-standing childhood-onset type 1 diabetes in individuals reaching older age. Type 1 diabetes diagnosed after age 30 years presents diagnostic and management challenges. Diagnosis remains difficult due to high prevalence of type 2 diabetes and frequent misclassification. When adult-onset type 1 diabetes is rigorously defined, key clinical features, including progression from dysglycemia and early β-cell decline, more resemble those in younger individuals. Differences across ages are best interpreted as an age-related phenotype arising from the biological context in which autoimmunity occurs, immune remodeling, insulin resistance, and pancreatic changes, rather than distinct pathogenic mechanisms. While incidence of adult-onset type 1 diabetes is largely static, prevalence is increasing, especially among those ages ≥65 years, largely due to improved outcomes with declining mortality and disability-adjusted life-years. While type 1 diabetes management should not intrinsically alter with age, older adults face elevated risks of comorbidities, including frailty and cognitive and visual impairment, which can complicate management and impact glucose levels, particularly hypoglycemia risk; individualized glycemic targets are needed with a focus on safety and quality of life. Moving forward integrating adults into pre-type 1 diabetes screening and prevention efforts will be essential to refine prediction, reduce misclassification, and guide disease-modifying interventions.