In a recent cohort study published in JAMA Network Open, researchers from China investigated the effect of a multidisciplinary diabetes management program on the risk of dementia in patients with type 2 diabetes (T2D). They found that glycemic control may be linked to dementia incidence, and a diabetes management program could be beneficial for T2DM patients against dementia and its subtypes.
Study: Risk of Dementia Among Patients With Diabetes in a Multidisciplinary, Primary Care Management Program. Image Credit: Africa Studio / Shutterstock
Background
Dementia is a significant global health burden, especially among older adults, with the incidence rising particularly in those with T2D. T2D is linked to a 50% higher likelihood of all-cause dementia, and its association with Alzheimer's disease (AD) and other dementias involves various pathological features, including vascular damage, amyloid-β accumulation, and neuroinflammation. While higher hemoglobin A1C (HbA1C) levels in T2D patients are linked to increased dementia risk, the effectiveness of glycemic control interventions in reducing dementia incidence remains uncertain. Multidisciplinary diabetes management programs show positive outcomes in mortality and diabetic complications. However, studies on their association with dementia outcomes, especially with longer follow-ups and individualized glucose control targets, are limited.
In Hong Kong, over 90% of T2D patients are managed within the public health care system, utilizing the multidisciplinary Risk Assessment and Management Program-Diabetes Mellitus (RAMP-DM) program since 2009. RAMP-DM demonstrated significant improvements in glycemic control and substantial reductions in mortality, macrovascular events, and microvascular events over a 9-year follow-up period. The current study investigates the association between RAMP-DM services, glycemic control, and the risk of all-cause dementia incidence, offering valuable insights into dementia prevention for T2D patients.
About the study
The present retrospective cohort study utilized electronic health records from Hong Kong's public health care system. Adult patients diagnosed with T2D in 2011, excluding those with type 1 diabetes, gestational diabetes, or pre-existing dementia, were identified. Patients attending RAMP-DM services plus usual care were in the treatment group, while those not joining RAMP-DM formed the control group. Follow-up (median 8.4 years) continued until the occurrence of outcome events, death, or the study's end in December 2019. Patients joining RAMP-DM services between 2012 and 2019 were excluded due to insufficient follow-up time for dementia outcomes.
A total of 55,618 patients were included (mean age 68.28 years; 51.4% females), with 27,809 patients each in the RAMP-DM group (median age 69 years) and the usual care group (median age 70 years).
The primary outcome was dementia incidence, identified through ICD-10 or ICPC-2 codes and dementia medication prescriptions. Dementia causes unrelated to alcohol, drugs, or infectious agents were considered. Diagnosis followed clinical assessments with reference to DSM-IV and DSM-5 criteria. Secondary outcomes included AD, vascular dementia (VD), and other types of dementia. The primary analysis focused on RAMP-DM use, with an exploration of early-stage HbA1C levels after joining RAMP-DM in relation to dementia incidence. Several covariates were extracted at the baseline. Participants with T2D who received RAMP-DM services were matched using a propensity score to those who received usual care only. The statistical analysis involved the use of baseline characteristic comparison, cumulative incidence rate estimation, crude absolute risk reduction (ARR), relative risk reduction (RRR), Kaplan-Meier curve, and multivariate Cox proportional hazard modeling.
Results and discussion
About 6.97% of the RAMP-DM group and 9.81% of the usual care group were diagnosed with dementia. The incidence rate of dementia per 1000 person-years was lower (9.31) for RAMP-DM than for usual care (14.02). RAMP-DM showed a significant risk reduction in all-cause dementia, AD, VD, and other forms of dementia. HbA1C levels were found to be lower in the RAMP-DM group, and RAMP-DM patients showed a 28% lower risk of all-cause dementia, 39% lower risk of VD, 15% lower risk of AD, and 29% lower risk of other dementias compared to usual care.
Sensitivity analysis consistently indicated similar findings. Subgroup analysis demonstrated RAMP-DM's risk reduction across various subgroups, with a more pronounced effect in patients with HbA1C ≤7.5% and those with hypertension. No significant differences were observed based on sex, public assistance, elderly home residency, or CCI score.
The analysis revealed an association between HbA1C levels during follow-up and dementia risk. Compared to the reference group (HbA1C = 6.5–7.5%), patients with levels between 7.5% and 8.5% and above 8.5% had a higher risk. Lower HbA1C levels (<6% and 6%-6.5%) were also associated with elevated dementia risk.
The study is limited by its observational design, potential selection bias, unmeasured baseline characteristics influencing dementia incidence, and information biases.
Conclusion
In conclusion, the study suggests that a primary care-based multidisciplinary diabetes management program is associated with reduced all-cause dementia risk in patients with T2D, emphasizing the importance of glycemic control. Prospective studies and trials are needed to confirm effectiveness and explore biological mechanisms.
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