Background

Type 2 diabetes (T2DM) prevalence is increasing, and cause of death and complications in this patient group are now much broader. The extent and breadth of morbidity and how this varies across sub-groups is unclear. We aimed to estimate comorbidity profiles in patients with T2DM, variations across sub-groups and over the disease course.

Methods

We identified approximately 224,000 patients with T2DM in the Discover-NOW dataset, a real-world primary care database from 2000-2020 covering 2.5 million people across North-West London, England, linked to hospital records. We generated a mixed prevalence and incidence study population through repeated annual cross sections, and included a broad set of 35 comorbidities covering traditional T2DM complications, emerging conditions and other common comorbidities.

We estimated annual age-standardised prevalence of comorbidities, over the course of the disease in patients with T2DM and several sub-groups, including age, gender, and specific comorbidities at baseline.

Results

Multimorbidity (>1 chronic condition) is common in patients with T2DM and increasing. Comorbidity profiles of patients with T2DM vary substantially. Nearly 30% of T2DM patients had three or more comorbidities at diagnosis, increasing to 60% of patients ten years later. Two of the five commonest comorbidities at diagnosis were expected (hypertension (37%) and ischaemic heart disease (10%)) the other three were not (depression (15%), back pain (25%) and osteoarthritis (11%)). The prevalence of each increased during the course of the disease, with more than 30% patients having back pain and 25% having depression ten years post diagnosis. Patients with obesity at diagnosis had substantially different comorbidity profiles to those without, and the five commonest comorbidities were 50% more common in this group.

Discussion

Preventative and clinical measures alongside care pathways for patients with T2DM should evolve to reflect the diverse set of causes driving persistent morbidity to benefit patients and healthcare systems alike.