Background Energy drinks have been linked to an increase in emergency room visits and deaths. We aim to determine the impact of energy drinks on electrocardiographic and hemodynamic parameters in young healthy volunteers. Methods and Results A randomized, double‐masked, placebo‐controlled, crossover study was conducted in healthy volunteers. Participants consumed 32 oz of either energy drink A, energy drink B, or placebo within 60 minutes on 3 study days with a 6‐day washout period in between. The primary end point of QT c interval and secondary end points of QT interval, PR interval, QRS duration, heart rate, and brachial and central blood pressures were measured at baseline, and every 30 minutes for 240 minutes. A repeated‐measures 2‐way analysis of variance was performed with the main effects of intervention, time, and an interaction of intervention and time. Thirty‐four participants were included (age 22.1±3.0 years). The interaction term of intervention and time was statistically significant for Bazett's corrected QT interval, Fridericia's corrected QT interval, QT , PR , QRS duration, heart rate, systolic blood pressure, diastolic blood pressure, central systolic blood pressure, and central diastolic blood pressure (all P <0.001). The maximum change from baseline in Bazett's corrected QT interval for drinks A, B, and placebo were +17.9±13.9, +19.6±15.8, and +11.9±11.1 ms, respectively ( P =0.005 for ANOVA ) ( P =0.04 and <0.01, respectively compared with placebo). Peripheral and central systolic and diastolic blood pressure were statistically significantly different compared with placebo (all P <0.001). Conclusion Energy drinks significantly prolong the QT c interval and raise blood pressure. Clinical Trial Registration URL : http://www.clinicaltrials.gov . Unique identifier: NCT 03196908.

Elevated blood pressure (BP) is a leading modifiable risk factor for cardiovascular disease and continues to affect approximately 1 in 3 adults, or 66.9 million people, in the United States. 1 Traditionally, hypertension is diagnosed and treated by assessing the pressure at the brachial artery (peripheral BP), 2 but recent evidence suggests that central hemodynamics are better predictors of cardiovascular outcomes and mortality. 3,4 Central BP is indicative of the pressure directly exerted on target organs and often varies from peripheral BP. 2 Aortic and carotid arteries are more elastic than fibrous peripheral vasculature and the difference in peripheral and central pressures is thought to be a result of amplification due to wave reflections caused by the variance in arterial stiffness. 2,5 As a result of arterial stiffness increasing with distance from the heart, peripheral systolic BP (pSBP) tends to be greater than central systolic BP (cSBP). 6 Additionally, augmentation index (AI), which measures the degree of enhancement in the central pressure waveform due to reflected waves, has been shown to be an independent predictor of cardiovascular events. 4 Recent technology has increased the availability of several noninvasive techniques to estimate central BP allowing for incorporation of these parameters in a multitude of patient populations and disease states. [7][8][9][10] Differences between the various classes of antihypertensive agents regarding their effects on central hemodynamics have been identified. 11,12 The Conduit Artery Function Evaluation (CAFE) study 13 was one of the first trials to show differing clinical outcomes despite similar reductions in peripheral BP. In a previous meta-analysis, differing responses of β-blockers (BBs) and diuretics on central hemodynamics were implied but extrapolation of their finding was limited due to a modest number of included studies. 12 As a result of a greater number of new publications in the last few years assessing the effects of antihypertensives on central BP, we performed a meta-analysis analyzing the differential effects of antihypertensive agents on cSBP and AI. An assessment as such will help better determine the incorporation and place in therapy of the various antihypertensives in clinical practice. Impact of Antihypertensive Agents on BACKGROUNDNew evidence suggests that central systolic blood pressure (cSBP) and augmentation index (AI) are superior predictors of adverse cardiovascular outcomes compared to peripheral systolic BP (pSBP). We performed a meta-analysis assessing the impact of antihypertensives on cSBP and AI.

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Introduction: New evidence suggests central systolic blood pressure (cSBP) is a superior predictor of adverse cardiovascular outcomes as compared to peripheral systolic blood pressure (pSBP). Additionally, augmentation index (AI) provides a surrogate assessment of vascular stiffness. We performed a meta-analysis to assess the impact of antihypertensive drug classes on cSBP and AI. METHODS: Search terms related to blood pressure and AI were used to identify relevant articles in PubMed, Cochrane Library and CINAHL limited to randomized trials in humans and publications in English. Appropriate data on cSBP, pSBP and AI were extracted along with other study characteristics. Weighted mean differences (WMD) between the pSBP and cSBP with 95% confidence intervals (CI) were calculated using the DerSimonian-Laird random-effects methodology. For AI, the WMD from baseline was determined. Further, the data was sorted by antihypertensive class (angiotensin converting enzyme inhibitors (ACE-Is), angiotensin II receptor blockers (ARBs), beta-blockers (BBs), calcium channel blockers (CCBs) and diuretics) to determine their impact on cSBP and AI. Subgroup analyses were performed to assess robustness of results by limiting to the fixed-effects model, a primary diagnosis of hypertension, and excluding studies with JADAD scores < 3. Publication bias was assessed using the Egger’s statistic and visual inspection of funnel plots. Statistical heterogeneity was assessed using the I2 statistic. RESULTS: Fifty-one and 58 studies incorporating 4381 and 3716 unique subjects were included for cSBP and AI respectively. Overall, antihypertensives reduced pSBP more than cSBP (2.52mmHg, 95%CI 1.35 to 3.69; I2 =21.9%). ACE-Is, ARBs, CCBs and diuretics reduced cSBP and pSBP in a similar manner (-2.40mmHg, 95%CI -4.89 to 0.08; 1.12mmHg, 95%CI -2.25 to 4.49; 1.01mmHg, 95%CI -2.17 to 4.19; 0.65mmHg, 95%CI -2.47 to 3.77 respectively). BBs posed a significantly greater reduction in pSBP as compared to cSBP (5.19mmHg, 95%CI 3.21 to 7.18). The change in AI from baseline was (-3.09, 95%CI -3.90 to -2.28; I2 =84.5%). A significant reduction in AI was seen with ACE-Is, ARBs, CCB and diuretics (-5.61, 95%CI -6.95 to -4.27; -5.28, 95%CI -8.61 to -1.95; -5.36, 95%CI -6.95 to -3.77; -3.24, 95%CI -5.45 to -1.03 respectively). BBs reduced AI non-significantly (-0.32, 95% CI -1.48 to 0.84). While the Egger’s statistic showed a lack of publication bias (p>0.125), it cannot be ruled out based on visual inspection of funnel plots. CONCLUSIONS: BBs are not as beneficial in reducing cSBP as opposed to ACE-Is, ARBs, CCBs and diuretics. In contrast, ACE-Is, ARBs, CCBs and diuretics significantly reduce AI, which is not evident with BB therapy. The views expressed in this material are those of the author(s), and do not reflect the official policy or position of the U.S. Government, the Department of Defense, or the Department of the Air Force.