Compared with adults with type 2 diabetes, adults with type 1 diabetes experience an overall greater risk for cardiorenal disease—heart failure and chronic kidney disease—at all ages, as well as higher risks for total age-adjusted cardiorenal disease burden, according to research results published in Diabetes Care.
In order to directly compare both incidence and prevalence of cardiorenal disease in patients with type 1 and type 2 diabetes, researchers conducted an observational, longitudinal, full population study using data from 2 large, full-population registries in Norway and Sweden.
In total, 59,331 patients with type 1 diabetes and 484,241 patients with type 2 diabetes were included in the study. Data were pooled due to comparable results from both country cohorts. At baseline, 87.5% of patients with type 2 diabetes were taking any glucose-lowering drug. Patients with type 1 diabetes were younger than those with type 2 diabetes (mean age, 45.8 vs 64.1 years) and also had a lower prevalence of cardiovascular disease (13.3% vs 26.2%). Similar proportions of chronic kidney disease were noted (4.3% vs 3.3%), although microvascular complications were more common due to increased incidence of diabetic retinopathy.
Over the follow-up period, event rates were low in participants aged <40 years. Heart failure event rates were significantly higher in patients with type 1 diabetes between 65 and 79 years of age (hazard ratio [HR], 1.31-1.39), while similar findings for myocardial infarction were noted for patients aged 55 to 79 years (HR, 1.30-1.79). Stroke rates were significantly higher in type 1 diabetes, but only among younger patients between 40 and 54 years of age (HR, 1.35-1.72).
The incidence of chronic kidney disease was higher for patients with type 1 diabetes as compared to patients with type 2 diabetes at all age groups (although intergroup differences were noted and generally decreased as age increased).
Risk for any cardiorenal disease event was significantly higher in people with type 1 diabetes across all age groups (HR, 1.20-1.60), and cardiovascular mortality rates were higher in people with type 1 diabetes at ages 55 to 64 and 70 to 79 years (HR, 22.214.171.124); similar findings were noted for total cardiovascular events between 55 and 79 years of age (HR, 1.14-1.42).
Investigators performed subgroup analyses in patients who did not have cardiorenal disease at baseline, and among those with previous cardiorenal disease. In the first group, the “only significant difference” between type 1 and type 2 diabetes were increased myocardial infarction rates among people with type 1 diabetes between 70 and 79 years of age (HR, 1.41-1.70) and increased cardiovascular mortality between 75 and 79 years of age (HR, 1.78).
Study limitations include an inability to accurately determine diabetes duration for the type 2 diabetes population, a lack of data on several important risk factors associated with an increase in cardiorenal disease rates including HbA1c, blood lipids, blood pressure, and obesity, and the use of hospital ICD codes and a lack of access to primary care data, potentially underestimating events in the type 2 diabetes population.
“[Cardiorenal disease] burden among patients with [type 1 diabetes] is at least as heavy in patients with [type 2 diabetes] following age stratification,” the researchers concluded. “There is a remaining need to reinforce and evaluate additional preventive approaches, beyond glycemic control, also in patients with type 1 diabetes.”
Disclosure: This clinical trial was supported by AstraZeneca. Please see the original reference for a full list of authors’ disclosures.
Kristófi R, Bodegard J, Norhammar A, et al. Cardiovascular and renal disease burden in type 1 compared with type 2 diabetes: A two-country nationwide observational study. Published online March 2, 2021. Diabetes Care. doi: 10.2337/dc20-2839