The findings, published in The Lancet, come from a large observational study in Sweden that followed over 27,000 individuals with type 1 diabetes and more than 135,000 matched controls for an average of 10 years.
Being diagnosed with type 1 diabetes at a young age is associated with more cardiovascular complications and higher risk of premature death than being diagnosed later in life, independent of disease duration.
With around half of individuals with type 1 diabetes diagnosed before the age of 14, the authors stress the need to consider wider and earlier use of cardioprotective measures such as statins and blood pressure lowering drugs in this high-risk population.
The new estimates suggest that individuals diagnosed before the age of 10 have a 30-times greater risk of serious cardiovascular outcomes like heart attack and heart disease than those in the general population, whilst risk levels are around six times higher for people diagnosed between ages 26 and 30.
People with younger-onset type 1 diabetes are four times as likely to die from any cause, and have more than seven times the risk of dying from cardiovascular disease than their diabetes-free counterparts.
In contrast, people first diagnosed between ages 26 and 30 face a lower risk of dying from any cause and cardiovascular disease compared to their peers without diabetes.
Co-author Professor Naveed Sattar, from the University of Glasgow’s Institute of Cardiovascular and Medical Sciences, said: “While the absolute risk levels are higher in individuals who develop diabetes when older, simply due to age being a strong risk factor, the excess risk compared to healthy controls is much higher in those who developed diabetes when younger.
“If this higher excess risk persists over time in such individuals, they would be expected to have highest absolute risks at any given subsequent age. Indeed, those who develop type 1 diabetes when under 10 years of age experience the greatest losses in life expectancy, compared to healthy controls. This is something we did not fully appreciate before.”
The impact of type 1 diabetes on younger people should not be underestimated, and there is a need to consider adding recommendations about age of onset in future guidelines, say the authors.
Type 1 diabetes mellitus is the second most common chronic disease in children, accounting for 85 per cent of diabetes in the under 20s. But it is not unusual to develop the disease as an adult. Worldwide, the incidence of type 1 diabetes in children aged 14 years and younger has risen by three per cent a year since the 1980s.
It is well known that people with type 1 diabetes are at increased risk of health problems and have shorter life expectancies, partly due to premature cardiovascular disease. But, until now, the impact of age of diagnosis on this excess mortality and cardiovascular risk was unclear.
Professor Sattar said: “People with early onset diabetes should more often be considered for cardioprotective drugs such as statins and blood pressure lowering medication when they reach 30 to 40 years of age. Currently, only around 10 to 20 per cent of individuals with type 1 diabetes are taking statins by the age of 40.
“Also, improving glycaemic control and smoking cessation programmes could meaningfully prolong the lives of these individuals. The good news, however, is that recent technological advances are helping younger patients manage their glucose levels better.”