Glycemic variability and cardiovascular disease in type 1 diabetes

Abstract

Risk factors for cardiovascular disease (CVD) are well established in type 2 diabetes, but not in type 1 diabetes (DM1). Blood glucose as assessed by Hb A1c is generally considered the most powerful risk factor for CVD in T1D, with other traditional CVD risk factors (blood pressure, low-density lipoprotein cholesterol) having an independent contribution¹. People with DM1 have a 5- to 10-fold relative risk of experiencing a coronary heart disease (CHD) event compared to people without diabetes. The risk is even higher with a younger age of onset. At the age of 20 years, life expectancy is reduced by ≈12 years in absolute terms, with approximately one-third of the excess risk being attributable to cardiovascular disease¹.

The American Diabetes Association and the European Association for the Study of Diabetes recently updated their treatment guidelines for the management of T2DM that include an additional focus on cardiovascular risk. Better management of cardiovascular risk factors in DM1 is also needed. There are important differences in the pathophysiology of CVD in DM1 and DM2. Hyperglycemia appears to have a more profound effect on cardiovascular risk in DM1 than in DM2, and other risk factors appear to cause a synergistic rather than additive effect, so achieving treatment goals for all risk factors recognized risk is crucial to reduce cardiovascular risk in DM1². The acceleration of atherosclerosis in T1DM is likely due to many different pathways including the effects of inflammation, dyslipidemia, hypertension, nephropathy, glycemic variability, and hypoglycemia³. Known risk factors appear to operate differently in T1DM, suggesting a difference in the pathophysiology of CVD⁴. Despite the numerous studies that evaluate the presence of cardiovascular risk factors to predict which patients will present complications and focus on prevention, more studies will be needed in the future to evaluate which risk markers prevail in people with DM1 and generate greater cardiovascular risk.