Diabetes duration and the risk of dementia: a cohort study based on German health claims data

Abstract

Objective Diabetes is a risk factor for dementia but little is known about the impact of diabetes duration on the risk of dementia. We investigated the effect of type 2 diabetes duration on the risk of dementia. Design Prospective cohort study using health claims data representative for the older German population. The data contain information about diagnoses and medical prescriptions from the in- and outpatient sector. Methods We performed piecewise exponential models with a linear and a quadratic term for time since first type 2 diabetes diagnosis to predict the dementia risk in a sample of 13,761 subjects (2,558 dementia cases) older than 65 years. We controlled for severity of diabetes using the Adopted Diabetes Complications Severity Index. Results We found a U-shaped dementia risk over time. After type 2 diabetes diagnosis the dementia risk decreased (26% after 1 year) and reached a minimum at 4.75 years, followed by an increase through the end of follow-up. The pattern was consistent over different treatment groups, with the strongest U-shape for insulin treatment and for those with diabetes complications at the time of diabetes diagnosis. Conclusions We identified a non-linear association of type 2 diabetes duration and the risk of dementia. Physicians should closely monitor cognitive function in diabetic patients beyond the first few years after diagnosis, because the later increase in dementia occurred in all treatment groups.

Alterations of Cerebral Blood Flow and Its Connectivity in Olfactory-Related Brain Regions of Type 2 Diabetes Mellitus Patients

“…Further, we found that T2DM patients requiring antidiabetic drugs had a longer duration of disease than Non-drug patients ( Supplementary Table 2 , P < 0.001). This may be related to the fact that these patients with advanced diabetes tend to have more severe brain abnormalities due to their continued deterioration of islet function ( Reinke et al, 2022 ).…”

Microvascular Changes in the Retina Correlate with MRI Markers in Patients with Early-Onset Dementia

“…We also found that SVC density in EOD patients significantly correlated with PWMH scores assessed with the Fazekas scale. Retinal imaging studies using fundus photography showed that changes in the retinal vein (located in the SVC) are associated with cardiovascular risk factors such as hypertension [ 44 , 45 ] and diabetes [ 46 , 47 ], which are linked with dementia. Besides, it has been hypothesized that enlargement of the retinal venules reflects endothelial dysfunction [ 48 ], which is a classical indicator of ischemia in the retina and hypoperfusion.…”

Analyses and identification of ICD codes for dementias in the research based on the NHIRD: a scoping review protocol

“…However, due to the natures of administrative data or claims data, which are usually presumed for reimbursement rather than for research,5 6 scholars have proposed important issues that may pose threats and limitations to such studies, including the quality and reliability of the data,7 8 the lack of consensus and standardisation across the databases, and the doubt of data accuracy as a result of erroneous linkage 9 10. Furthermore, despite being powerful, studies based on HCD are still vulnerable to the under-recording of dementia, resulting in under-representativeness of the target group and threats to generalisability of the study results 11…”