Adding to a growing body of evidence that elevated remnant cholesterol (remnant-C) provides additional and independent risk prediction for major cardiovascular events (MACE), a new analysis has this shown this biomarker has prognostic value specifically in patients with type 2 diabetes (T2D).
In a post hoc analysis of the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial, each standard-deviation increase in remnant-C was associated with a 7% increased risk in MACE (P = .004) after adjustment for several risk factors including other cholesterol values.
“In type 2 diabetes, remnant-C levels are associated with MACE regardless of LDL-C,” reported a team of investigators led by Liyao Fu, MD, Second Xiangya Hospital of Central South University, Changsha, China .
Remnant-C is one component of triglyceride-rich lipoproteins. Within triglyceride-rich lipoproteins, remnant-C has become a major focus of efforts to explain cardiovascular (CV) residual risk, according to the investigators.
Residual risk is a term used to explain why cardiovascular events occur after all known modifiable factors, such as LDL cholesterol (LDL-C), are controlled.
“Our primary findings indicate that baseline estimated remnant-C levels were associated with MACE regardless of clinical phenotypes, lifestyle confounders relative to CV risk, and lipid-lowering treatment,” said the authors of the analysis.
In the post hoc analysis of the ACCORD trial, which evaluated the effects of intensive glucose lowering in T2D more than 10 years ago, there were data on remnant-C over a median of 8.8 years of follow-up in 9,650 T2D patients. Over this period, 1,815 (17.8%) developed MACE.
Multiple analyses support prognostic value of remnant-C
In addition to the 7% rise in MACE for each standard-deviation increase in remnant-C when calculated as a continuous variable, other analyses told the same story.
This included an assessment by remnant-C tertiles. Not only was there a significant trend (P < .001) for greater risk with each higher baseline tertile of remnant-C, those in the highest tertile had a 38% greater risk of MACE relative to those in the lowest tertile (hazard ratio, 1.38; P < .001) after adjustment for confounders.
The same pattern was seen for several components of MACE, such as CV death and nonfatal myocardial infarction, when remnant-C tertiles were compared.
Visit-to-visit variability in remnant-C over the course of follow-up was also associated with greater risk of MACE. In logarithmic calculations, the risk of MACE climbed about 40% across all three models of risk adjustment. These models included adjustments for different sets of confounders, such as sex, age, blood pressure, CV disease history, and glucose levels. On an unadjusted basis, the risk was increased about 50% (HR, 1.52; P < .001).
For visit-to-visit variability in remnant-C, the greatest effect was on risk of nonfatal MI across models. In model 3, for example, which adjusted for the most confounders, the risk was nearly doubled (HR, 1.92; P < .001). In contrast, there did not appear to be a link between visit-to-visit variability and nonfatal stroke.
In a discordant analysis that was conducted to examine the relative risk of remnant-C independent of LDL-C, those who had a remnant-C level of at least 31 mg/dL were found to have a higher risk of MACE regardless of LDL-C level. Yet, the risk was higher if both remnant-C and LDL-C were elevated. For example, the risk was increased 22% for those with LDL-C at or below 100 mg/dL and remnant-C levels of at least 31 mg/dL (HR, 1.22; P = .015) but climbed to 37% for those with LDL-C above 100 mg/dL if remnant-C was at least 31 mg/dL (HR, 1.38; P = .007).