Remnant Cholesterol: From Pathophysiology to Clinical Implications in Type 1 Diabetes

Remnant cholesterol, contained within triglyceride-rich lipoproteins such as VLDL and IDL, has emerged as an independent risk factor for atherosclerotic cardiovascular disease (ASCVD) in both the general population and individuals with diabetes. Unlike LDL cholesterol, remnant cholesterol has not traditionally been a therapeutic target, despite growing evidence of its role in the pathophysiology of atherosclerosis. These particles exhibit high atherogenic and pro-inflammatory potential, and their metabolism is altered in states of insulin resistance and hepatic dysfunction, both common in diabetes. Epidemiological studies have shown its association with ischemic heart disease, peripheral artery disease, progression of nephropathy, and cardiovascular events in type 2 diabetes. In individuals with type 1 diabetes (T1D), the evidence is more recent but relevant: elevated levels of remnant cholesterol have been linked to persistent hyperglycemia, diabetic nephropathy, diabetic foot, subclinical myocardial dysfunction, and carotid atherosclerosis, even when LDL-C levels are within target range. Moreover, lifestyle factors such as physical activity and a healthy diet are associated with lower levels of remnant cholesterol, suggesting opportunities for non-pharmacological interventions. Despite this, treatments targeting remnant cholesterol have shown limited efficacy in reducing clinical events, and individuals with T1D remain underrepresented in clinical trials. Overall, this review highlights the need to incorporate remnant cholesterol into the assessment of residual cardiovascular risk and into personalized therapeutic strategies, especially for vulnerable populations such as those with T1D.