• diabetes
• coronary artery disease

Observational studies show strong associations between diabetes and risk of ischaemic heart disease (IHD).1 Data, mainly from population-based cohorts in high-income countries, suggest that diabetes approximately doubles the risk of IHD, and this association may be doubled again in countries where healthcare resources to treat diabetes are limited.2 Diabetes associates with several known cardiovascular disease risk factors, but the persistence of this excess risk despite accounting for the effects of blood pressure, lipids and lifestyle factors (including smoking) suggests other important mediators of risk exist.1

Most large-scale observations of diabetes, glycaemic control and IHD have come from populations where type 2 diabetes predominates. In their Heart manuscript Matuleviciene Anängen and colleagues have studied IHD risk in type 1 diabetes and assessed how glycaemic control and reduced kidney function influence this risk.3 Studying these exposures in type 1 diabetes is an attractive strategy as the condition is often diagnosed in otherwise healthy young people without existing cardiovascular disease risk factors, and any reduced kidney function is likely a consequence of diabetes. This contrasts with type 2 diabetes, which generally develops later in life after possible prolonged exposure to other risk factors for IHD and chronic kidney disease (CKD), such as excess adiposity, high blood pressure or dyslipidaemias.

This large and important study from the Swedish National Diabetes Register included observations from 33 000 people with type 1 diabetes, with an average age …