The Impact of Dementia on Treatment Persistence among Older Adults with Type 2 Diabetes: A Register-Based Study in Sweden

Abstract

Background: Type 2 diabetes (T2D) and dementia represent a growing dual burden in aging
populations. These conditions share pathophysiological mechanisms that may create a self-reinforcing cycle in which cognitive impairment affects diabetes management, a crucial factor
for preventing complications. Despite Sweden's comprehensive care, there is limited longitudinal
evidence on how cognitive impairment impacts treatment persistence and complications in older
adults.
Aim: To investigate (1) the association between dementia and treatment persistence among older
adults on active diabetes therapy in Sweden, and (2) whether diabetes complications differ
between patients with and without dementia.
Methods: This register-based comparative cohort study used three Swedish health registries,
identifying 3,869 older adults with T2D on active medication (1,990 with dementia, 1,879
matched controls) from 2010 to 2016. Treatment non-persistence was defined as a gap exceeding
90 days between the expected end of a drug supply and the next dispensation, indicating a
discontinuation of diabetes therapy. Cox proportional hazards models analysed non-persistence
and diabetes complications, adjusting for demographic and clinical factors. Sensitivity analyses
used alternative definitions of treatment gaps (60 and 120 days).
Results: Older adults with dementia had a 31% higher risk of discontinuing diabetes treatment
compared to those without dementia (HR: 1.31, 95% CI: 1.20–1.44), with higher discontinuation
rates in the first year of follow-up (24.1% in cases vs 17.8% in controls). Advanced age (HR:
1.03 per year), foreign background (HR: 1.15), and a high comorbidity burden (HR: 1.30) were also associated with non-persistence. Adults with dementia experienced higher risks of stroke/TIA (HR: 1.84), while diabetic foot ulcers showed complex time-dependent patterns with initially high risks that decreased over time. Sensitivity analyses confirmed robustness across different definitions (HR: 1.71 for 60-day; HR: 2.34 for 120-day gaps).
Conclusion: Older adults with T2D and dementia are more likely to discontinue diabetes treatment and face an increased risk of cerebrovascular events. Our findings highlight the need for specialised monitoring systems that prioritise cardiovascular protection in patients with dementia, especially during the initial years after diagnosis, when discontinuation rates are highest. Integrated care that connects memory clinics, diabetes care, and elder support services may help manage their treatment more effectively and prevent complications in this population.

Popular Abstract

Managing diabetes becomes increasingly complex as people age, especially for those who also
develop dementia. This study examined how dementia impacts the continuity of diabetes
treatment among older adults in Sweden and whether diabetes complications vary between
individuals with and without dementia. Using data from national registers, we followed nearly
4,000 older adults with type 2 diabetes in Sweden for up to 6.5 years.
We found that older adults with dementia are 31% more likely to discontinue their diabetes
therapy compared to those without cognitive impairment, particularly during the first year after
diagnosis of dementia. This early discontinuation suggests a critical period of vulnerability that
may require additional support.
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Notably, our research also revealed that people with dementia have an 84% higher risk of
cerebrovascular events. This finding supports the possible link between treatment
discontinuation and severe complications, indicating that dementia may affect cerebrovascular
complications by disrupting diabetes management. Moreover, age emerged as a critical factor,
with each additional year increasing discontinuation risk by 3%, while those with multiple health
conditions were 30% more likely to stop treatment, and patients with foreign backgrounds faced
a 15% higher risk.
Our findings have important implications for healthcare providers, as they inform about the need
for targeted interventions shortly after diagnosis of dementia to help maintain treatment and
prevent complications. Sweden’s healthcare system, with its strong digital infrastructure and
universal coverage, provides a favourable environment to implement better monitoring of
medication adherence and support strategies such as annual screening for cognitive impairment,
specific clinical high-risk protocols for patients with dementia, and timely coordination between
memory clinics and diabetes care.
As the prevalence of both diabetes and dementia continues to rise globally, with projections
indicating 276 million older adults will have diabetes and 19 million Europeans will live with
dementia by 2050, understanding these relationships and their implications becomes increasingly
crucial for public health planning.

• author: Villegas Gomez, Treisy Malory ; Persson, Sofie and Jarl, Johan
• supervisor: Johan Jarl; Sofie Persson
• organization: Social Medicine and Global Health
• course: MPHN40 20251
• year: 2025
• type: H2 - Master's Degree (Two Years)
• subject: Medicine and Health Sciences
• keywords: treatment persistence, type 2 diabetes, dementia, older adults, register-based study
• language: English
• id: 9201499
• date added to LUP: 2025-09-17 19:15:55
• date last changed: 2025-09-17 19:15:55