Combined Oral Triglyceride and Glucose Tolerance Test After Acute Ischemic Stroke to Predict Recurrent Vascular Events: The Berlin "Cream&Sugar" Study

Abstract

Background: Elevated triglyceride and glucose levels are associated with an increased cardiovascular disease risk including ischemic stroke. It is not known whether the response to a combined oral triglyceride and glucose challenge after ischemic stroke improves identification of patients with increased risk for recurrent vascular events.

Methods: The prospective, observational Berlin "Cream&Sugar" study was conducted at 3 different university hospital sites of the Charité-Universitätsmedizin Berlin, Germany, between January 24, 2009 and July 31, 2017. Patients with first-ever ischemic stroke were recruited 3 to 7 days after stroke. An oral triglyceride tolerance test (OTTT) and consecutive blood tests before (t₀) as well as 3 (t₁), 4 (t₂), and 5 hours (t₃) after OTTT were performed in fasting patients. An oral glucose tolerance test was performed in all nondiabetic patients 3 hours after the start of OTTT. Outcomes of the study were recurrent fatal or nonfatal stroke as well as a composite vascular end point including stroke, transient ischemic attack, myocardial infarction, coronary revascularization, and cardiovascular death assessed 1 year after stroke. Cox regression models were used to estimate hazard ratios and corresponding 95% CIs between patients with high versus low levels of triglyceride and glucose levels.

Results: Overall 755 patients were included; 523 patients completed OTTT and 1-year follow-up. Patients were largely minor strokes patients with a median National Institutes of Health Stroke Scale score of 1 (0-3). Comparing highest versus lowest quartiles of triglyceride levels, neither fasting (adjusted hazard ratio_t0, 1.24 [95% CI, 0.45-3.42]) nor postprandial triglyceride levels (adjusted hazard ratio_t3, 0.44 [95% CI, 0.16-1.25]) were associated with recurrent stroke. With regard to recurrent vascular events, results were similar for fasting triglycerides (adjusted hazard ratio_t0, 1.09 [95% CI, 0.49-2.43]), however, higher postprandial triglyceride levels were significantly associated with a lower risk for recurrent vascular events (adjusted hazard ratio_t3, 0.42 [95% CI, 0.18-0.95]). No associations were observed between fasting and post-oral glucose tolerance test blood glucose levels and recurrent vascular risk. All findings were irrespective of the diabetic status of patients.

Conclusions: In this cohort of patients with first-ever' minor ischemic stroke, fasting triglyceride or glucose levels were not associated with recurrent stroke at one year after stroke. However, higher postprandial triglyceride levels were associated with a lower risk of recurrent vascular events which requires further validation in future studies. Overall, our results do not support the routine use of a combined OTTT/oral glucose tolerance test to improve risk prediction for recurrent stroke.

Keywords: cardiovascular disease; glucose; ischemic stroke; risk factor; triglyceride.