Mortality, Cardiovascular Risk Elevated in Adult-Onset T1D

TOPLINE:

Individuals who developed type 1 diabetes (T1D) in adulthood faced a higher risk for all-cause mortality and major adverse cardiovascular events (MACEs) than individuals from the general population without diabetes. Factors such as smoking, poor glycemic control, and overweight or obesity contributed to poor prognosis in these patients.

METHODOLOGY:

• Current knowledge on the prognosis of T1D is primarily derived from studies focused on childhood- or adolescent-onset T1D, with limited information regarding T1D diagnosed later in life, particularly after age 40.
• Researchers analyzed data from Swedish national registers to examine the prognosis of adult-onset T1D and identify related risk factors in 10,184 patients with adult-onset T1D and 375,523 patients with T2D, diagnosed between 2001 and 2020; 38.3% were diagnosed with T1D at the age of 40 years or older.
• Patients with diabetes were compared with 509,172 individuals from the general population without diabetes.
• Mortality (all-cause mortality, cardiovascular death, noncardiovascular death, and death from infection, cancer, diabetic coma, or ketoacidosis) was assessed, along with MACEs, defined as cardiovascular death or the first inpatient record of non-fatal myocardial infarction or stroke; the median follow-up was 10.2 years.
• In patients with adult-onset T1D, hazard ratios (HRs) for all-cause mortality and MACEs were estimated for eight risk factors based on the initial measurement at cohort entry: smoking, physical activity, body mass index, A1c levels, blood pressure, triglyceride levels, estimated glomerular filtration rate, and albuminuria.

TAKEAWAY:

• Patients with T1D had a higher risk for all-cause mortality (HR, 1.71; 95% CI, 1.60-1.84) and MACEs (HR, 1.30; 95% CI, 1.17-1.45) than control individuals; mortality from cardiovascular or noncardiovascular diseases, cancer, or infection was also higher in the T1D cohort.
• Patients with T1D had a lower incidence of MACEs (HR, 0.67; 95% CI, 0.60-0.75) but substantially higher mortality from diabetic coma or ketoacidosis (HR, 7.04; 95% CI, 4.54-10.9) than patients with T2D.
• Patients diagnosed with T1D at or after the age of 40 years had similarly elevated risks for mortality and MACEs as the entire T1D cohort; however, they had worse glycemic control and lower use of insulin pumps than those diagnosed earlier.
• After examining risk factors associated with mortality and MACEs in patients with T1D, researchers found that smoking and elevated A1c levels accounted for most deaths, while these factors, along with overweight or obesity were key contributors to MACEs.

IN PRACTICE:

“Our findings highlight the need for better glucose management in adult-onset T1D, including equal access and better adherence to advanced technology such as insulin pumps in older adults diagnosed with T1D. In addition, being overweight/obese accounted for the most MACE events, indicating the importance of weight management in people with T1D, especially those diagnosed after age 40 years,” the authors concluded.

SOURCE:

This study was led by Yuxia Wei, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden. It was published online on May 14, 2025, in European Heart Journal.

LIMITATIONS:

Data on prognostic factors were missing for control individuals and also for some patients with T1D. Despite the availability of data on glycemic control, information on glycemic variability was unavailable. This study was primarily conducted in a population of European ancestry, limiting generalizability to other ethnicities and countries. 

DISCLOSURES:

This study received support from the Swedish Research Council, the Swedish Diabetes Foundation, and the SRP Diabetes Postdoctoral Fellowship Programme at Karolinska Institutet. One author received support from University of Helsinki and grants from the Folkhalsan Research Foundation and the Academy of Finland. Another author reported receiving honoraria from several pharmaceutical companies.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.