Acute effects of caffeine on blood pressure and wave reflections in healthy subjects: should we consider monitoring central blood pressure?

Background: Data concerning blood pressure changes, acutely induced by caffeine consumption, are conflicting. Furthermore, limited data exist regarding central hemodynamic response to caffeine ingestion by healthy young subjects. We investigated the acute effect of coffee (80 mg of caffeine) and decaffeinated coffee on peripheral and central hemodynamics, as well as on wave reflections. Subjects: For this purpose, 16 healthy volunteers (eight females and eight males, mean age 29±3.2 years) were investigated. Methods: Repeated measurements were performed at baseline and 30, 60, 90 and 120 min after oral administration of each beverage in a double-blind crossover design. Aortic blood pressures, augmentation index (AI) and pressure (AP) and timing of reflected waves were evaluated by using applanation tonometry and pulse wave analysis. Results: Regular coffee increased central systolic (SBP) and diastolic pressure (DBP) from 96.2±9.9 to 101.1±10.1 mmHg, p=0.011 and from 72.6±9.4 to 76.5±9.0 mmHg, p=0.027, respectively, but no change was observed following consumption of decaffeinated coffee. Peripheral systolic blood pressure did not change significantly after the administration of either coffee. Augmentation index increased significantly following regular coffee consumption. The change in AI was significantly higher following regular compared to decaffeinated coffee consumption as shown by analysis of variance (ANOVA) for repeated measures (p=0.001). Conclusions: These caffeine effects reveal an unfavourable effect on wave reflections and therefore on left ventricular (LV) pulsatile afterload. It also revealed a significant acute effect of caffeine consumption on central hemodynamics which is not observed at peripheral pressures.