High Coronary Artery Calcium in Type 1 Diabetes Patients Despite Good Control, Study Finds
USA: People living with type 1 diabetes for more than 50 years continue to face significant risks of cardiovascular disease (CVD), even when their kidney function is preserved and metabolic control is excellent, according to a new study published in Diabetologia by Marc Gregory Yu and colleagues at the Joslin Diabetes Center.
The research focused on the Joslin “Medalists,” a unique group of individuals who have managed type 1 diabetes for at least half a century. Despite optimal cardiometabolic management—average blood pressure at 132/64 mmHg, LDL cholesterol of 2.10 mmol/l, HDL cholesterol of 1.69 mmol/l, and median HbA1c of 7.1%—these participants displayed a strikingly high burden of coronary atherosclerosis.
Based on the study, the researchers reported the following findings:
- Among 1,038 participants analyzed, 40% reported cardiovascular disease, while 32% had diabetic kidney disease (DKD).
- Coronary artery calcium (CAC) scoring was performed in 142 participants, and cardiac magnetic resonance imaging (CMR) in 111.
- The median CAC score was 937, with no significant difference between those with and without DKD (1,136 vs. 878, respectively).
- In individuals without DKD, HbA1c was significantly associated with cardiovascular disease risk (odds ratio 1.40).
- Neither hypoglycemia nor glycemic variability showed significant associations with cardiovascular disease.
- Osteopontin (OPN) was the only inflammatory biomarker independently linked to cardiovascular disease in this subgroup (β = 0.50).
In the study, DKD did not appear to be a major driver of coronary atherosclerosis in this highly resilient cohort, likely due to relatively mild kidney impairment and survivor bias—these participants represent individuals who have endured type 1 diabetes for decades with relatively good health. The researchers acknowledged that their study’s cross-sectional design and smaller subgroup sizes may limit the generalizability of findings.
Still, the findings raise critical clinical implications. “Even in individuals with long-standing type 1 diabetes and excellent cardiometabolic profiles, a high coronary calcium burden persists,” the authors noted. This suggests that controlling hyperglycemia and reducing inflammation—particularly targeting osteopontin—could be essential strategies for mitigating cardiovascular risk in this population.
The study emphasizes the importance of comprehensive cardiovascular screening in aging individuals with type 1 diabetes, including routine imaging and biomarker assessments, regardless of kidney status. While further longitudinal studies are needed, the evidence underscores that exceptional glycemic control alone may not eliminate heart disease risk in those with decades-long diabetes.
As Yu and colleagues conclude, a proactive approach addressing both blood glucose and inflammation, alongside continued research into biomarkers like osteopontin, could be key to improving outcomes for people living with type 1 diabetes well into later life.
Reference:
Yu, M.G., Shah, H., Jangolla, S. et al. Risk and protective factors for coronary atherosclerosis and myocardial dysfunction in individuals with long-duration type 1 diabetes. Diabetologia (2025). https://doi.org/10.1007/s00125-025-06521-4
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