In patients with type 2 diabetes (T2D) and/or cardiovascular disease (CVD), elevated triglyceride levels were found to be an independent risk factor associated with adverse cardiovascular outcomes, according to a study published in the American Journal of Cardiology.
The study, which used data from the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial, sought to determine the prevalence and distribution of hypertriglyceridemia and examine the associations between baseline triglyceride levels and cardiovascular events overall. Participants in the original BARI 2D trial were randomized by whether they were receiving cardiovascular treatment or type 2 diabetes treatment. The protocol included guideline-mandated treatment for hypertension, dyslipidemia and obesity, in addition to a goal HbA1c of <7.0% regardless of randomization assignment. Lipid measures were obtained from fasting blood acquired prior to randomization.
The primary endpoint of the current analysis was time to death due to cardiovascular outcomes, myocardial infarction, or stroke. Secondary outcomes were the individual components of the primary endpoint in addition to time to coronary revascularization and all-cause death. Participants were grouped by baseline triglyceride levels; those with elevated triglyceride levels were further stratified into 3 groups: ≥150 to 199 mg/dL; 200 to 499 mg/dL; ≥500 mg/dL.
The study population consisted of 2307 patients (97% of the BARI 2D study; median age, 62 years). Most patients were obese, had a history of T2D just under 10 years, and were prescribed a statin. Overall, 51% of patients had triglyceride levels <150 mg/dL; 18%, 150 −199 mg/dL; 28%, 200−499 mg/dL; and 3%, 500−1000 mg/dL. Patients in the highest triglyceride level group were more likely to be younger, current smokers, have lower HDL-C cholesterol, and higher insulin levels.
Elevated baseline triglyceride levels were associated with the primary composite outcome of cardiovascular death, myocardial infarction, and stroke. In adjusted analysis, every 50 mg/dL increase in triglyceride level was associated with a 3.2% increase in cardiovascular death, myocardial infarction, or stroke and a 5.8% increase in cardiovascular death alone. In the fully adjusted analysis, every 50 mg/dL increase in triglyceride level was associated with a 3.8% increase in the primary composite outcome and a 6.4% increase in the secondary outcome.
Inclusion of age, sex, region, race, ethnicity, systolic blood pressure, and smoking status covariates modestly increased the impact of triglyceride levels on risk for adverse cardiovascular outcomes. In contrast, the addition of body mass index, T2D duration, HbA1c level, LDL-C, and statin use all modestly attenuated the impact of triglyceride levels on risk for both outcomes.
“Whether lowering [triglyceride] levels leads to improved cardiovascular outcomes remains to be seen,” concluded the authors.
Disclosure: A number of authors of the study have received research grants and fees from the pharmaceutical industry.
Nelson AJ, Navar AM, Mulder H, et al. Association between triglycerides and residual cardiovascular risk in patients with type 2 diabetes mellitus and established cardiovascular disease (from the Bypass Angioplasty Revascularization Investigation 2 Diabetes [BARI 2D] Trial). Am J Cardiol. Published online July 11, 2020. doi:10.1016/j.amjcard.2020.07.005.