Abstract 12194: The Modulatory Effects of Glucagon-Like Peptide-1 (GLP-1) on Coronary Flow Reserve During Acute Hyperglycemia in Type 2 Diabetics: A Prospective Controlled Study Using Bedside Myocardial Contrast Echocardiography
Background: We evaluated the effect of Glucagon-like peptide-1 (GLP-1) on Coronary Flow Reserve (CFR) in type 2 diabetes (T2D).
Methods: We enrolled 29 subjects with no CAD [8 T2D and 21 controls (CONT)]. T2D underwent 2 study visits (T2D-GLP-1 visit: GLP-1 infusion at 1.2 pmol/kg/min and T2D-NS visit: normal saline (NS) infusion) while CONT underwent one visit with NS infusion. During each visit, two stage pancreatic clamp (somatostatin, glucagon and insulin: 0.75 mU/Kg TBW/min) was infused, along with glucose to maintain euglycemia followed by hyperglycemia (each 2 hr stages). Blood glucose (BG) was monitored/10 minutes. Myocardial contrast echocardiography (MCE) was performed during steady state of each glycemic stage (Definity 1.3 ml diluted in 60 cc 0.9% saline at 200 ml/hr) at rest and during regadenoson vasodilator stress (400 ug IV bolus). CFR was quantified.
Results: CONT group [24% male, age 47.6±5 yrs, BMI 25.4 ± 4 kg/m2, fasting BG 88.6± 4.9 mg/dL, HbA1C 5.3± 0.3%]. T2D group [75% male, age: 53.9± 6 yrs, BMI: 31.9± 4 kg/m2, fasting BG 142.6± 22 mg/dL, HbA1C 7.2± 0.7%, DM duration 5 ± 2.7 yrs]. BG in T2D-GLP-1 vs T2D-NS vs CONT during euglycemia was 93.5 ± 4.8 vs. 95.7 ± 5.3 vs. 93.9 ± 7.3 mg/dL, P=0.797, while hyperglycemia BG was 230.5 ± 12.9 vs. 238.1 ± 11.4 vs. 231.5 ± 18.1 mg/dL, P=0.557, respectively. Mean CFR during hyperglycemia was significantly reduced vs euglycemia in CONT (p≤0.001), and T2D-NS (P=0.038), but not significant in T2D-GLP-1 (P=0.251), Figure. For Euglycemia stage, CFR was significantly lower in T2D-NS and T2D-GLP-1 vs. CONT. For Hyperglycemia stage, CFR was significantly lower in T2D-NS vs. CONT but not different in T2D-GLP-1 vs CONT. Figure.
Conclusions: CFR, as determined by MCE, is lower in euglycemic diabetics than controls. Hyperglycemia reduces CFR in both diabetics and controls. GLP-1 infusion appears to modulate the magnitude of CFR reduction during acute hyperglycemia in diabetics, suggesting a protective cardiovascular effect of this incretin.
- © 2013 by American Heart Association, Inc.