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)

Triglyceride (TG) levels encompass several lipoproteins that have been implicated in atherogenic pathways. Whether TG levels independently associate with cardiovascular disease both overall and, in particular among patients with established coronary artery disease (CAD) and type 2 diabetes (T2DM), remains controversial. Data from the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial was used to evaluate patients with T2DM and CAD. Cox proportional hazards models were used to determine the association between TG levels and outcomes. Stepwise adjustment was performed for demographics, clinical factors, lipid profile and statin treatment. The primary composite outcome was time to CV death, myocardial infarction (MI), or stroke and secondary outcome was CV death. Among 2,307 patients with T2DM and CAD, the mean (±SD) TG levels were 181 (±136) with a median (Q1-Q3) 148mg/dL (104-219). Overall, 51% of patients had TG <150 mg/dL, 18% 150-199 mg/dL, 28% 200-499 mg/dL and 3% ≥500 mg/dL. Participants with elevated TG levels (≥150 mg/dL) were younger (61 vs 63 years, p <0.001), had higher BMI (32 vs 30 kg/m², p <0.001), more likely to have had prior MI (34.2 vs 30.1%, p = 0.033) and revascularization (25.8 vs 21.4%, p = 0.013), had lower HDL-C (34 vs 39 mg/dL, p <0.001) and higher HbA1c (8 vs 7%, p <0.001). In unadjusted analyses, baseline TG levels were linearly associated with both the primary composite and secondary outcomes. In fully adjusted analyses, every 50 mg/dL increase in TG level was associated with a 3.8% (HR 1.038, 95%CI 1.004-1.072, p <0.001) increase in the primary composite outcome and a 6.4% (HR 1.064 95%CI 1.018-1.113, p <0.001) increase in the secondary outcome. There was no interaction between TG and outcomes within key subgroups including female sex, additional non-coronary atherosclerotic disease, CKD or low LDL (<100 mg/dL). In conclusion, among patients with T2DM and CAD, elevated TG were independently associated with adverse cardiovascular outcomes, even after adjustment for clinical and simple biochemical covariates.