Cardiovascular disease in type 1 diabetes

Cardiovascular disease (CVD) is a well-recognized complication of diabetes. Although the association of type 2 diabetes with CVD has been well described, the mechanisms, risk stratification and screening strategies of CVD in type 1 diabetes (T1D) are less understood. This review aims to evaluate recent literature and guidelines regarding CVD in T1D. At the cellular level, the early stage of CVD is characterized by endothelial dysfunction. Recent studies have shown that endothelial function is unaffected in younger T1D patients but there is a significant degree of endothelial dysfunction in the older T1D population compared with healthy age-matched controls, highlighting the importance of the endothelial dysfunction in T1D as a major age-dependent cardiovascular risk factor. T1D risk assessment tools have been developed similar to those seen in type 2 diabetes. Foremost among these are the Danish Steno Type 1 risk engine, the Swedish T1D risk score, the Scottish T1D risk score and the QRISK risk calculator. The latter risk prediction tool is used for all patients but contains T1D as an independent risk variable and has the advantage of being derived from, and validated in, a large and diverse population. The latest version (QRISK3) is likely to be recommended for routine use in T1D patients in upcoming guidelines by the National Institute of Clinical Excellence. Mortality in adults with T1D is increasingly due to CVD. This is driven by hyperglycaemia-mediated oxidative stress and vascular inflammation, resulting in atherosclerosis and cardiac autonomic neuropathy. Coronary artery disease is the most significant contributor to CVD and in T1D, has a propensity towards a more silent and severe form. Routine screening of coronary artery disease does not alter outcomes and is therefore not recommended; however, risk prediction tools are being developed to aid identification of high-risk individuals for aggressive risk factor modification strategies.