The impact of learning disabilities on control, management, and outcomes of type 2 diabetes mellitus in the UK: an observational cohort study using the Clinical Practice Research Datalink.

Abstract

Introduction: Adults with learning disabilities in the UK have a substantially higher risk of developing type 2 diabetes mellitus (T2DM) than the general population. This study aimed to assess the impact of living with learning disabilities on T2DM control, therapeutic management, vascular outcomes, and mortality in UK primary care.

Research design and methods: We conducted an observational cohort study using primary care electronic health records from the UK Clinical Practice Research Datalink. The study included adults newly diagnosed with T2DM from 2004 to 2021. The exposure was learning disability status at the time of diagnosis. Multivariable logistic regression was used to compare glycemic control at 5 years post-diagnosis between people with and without learning disabilities. Multivariable Cox regression was used to compare time to insulin initiation, macrovascular and microvascular complications, and mortality between people with and without learning disabilities.

Results: Of 280 300 adults with T2DM included in the study, 2074 (0.74%) had a learning disability at T2DM diagnosis. After adjustment, people with learning disabilities had lower odds of poor glycemic control than those without learning disabilities 5 years after diagnosis (OR=0.81, 95% CI 0.70 to 0.94) and faster insulin initiation (HR=1.20, 95% CI 1.00 to 1.45) than those without learning disabilities. The risks of all-cause and diabetes-related mortality were doubled in those with learning disabilities (all-cause HR=2.15, 95% CI 1.82 to 2.54; diabetes-related HR=1.93, 95% CI 1.32 to 2.80). We found no difference in the risk of vascular complications.

Conclusions: Individuals with learning disabilities had better glycemic control but shorter time to insulin initiation. This may be related to more frequent diabetes monitoring, or faster advancing T2DM requiring quicker treatment intensification. Despite having similar risks of vascular complications, people with learning disabilities were at higher risk of death. Future research into the mechanisms behind this could help reduce health disparities for people with T2DM and learning disabilities.