Synergistic effect of energy drinks and overweight/obesity on cardiac autonomic testing using the Valsalva maneuver in university students

Relationships between constituents of energy drinks and beating parameters in human induced pluripotent stem cell (iPSC)-Derived cardiomyocytes

Consumption of energy drinks has been associated with adverse cardiovascular effects; however, little is known about the ingredients that may contribute to these effects. We therefore characterized the chemical profiles and in vitro effects of energy drinks and their ingredients on human induced pluripotent stem cell (iPSC)-derived cardiomyocytes, and identified the putative active ingredients using a multivariate prediction model. Energy drinks from 17 widely-available over-the-counter brands were evaluated in this study. The concentrations of six common ingredients (caffeine, taurine, riboflavin, pantothenic acid, adenine, and L-methionine) were quantified by coupling liquid chromatography with a triple quadrupole mass spectrometer for the acquisition of LC-MS/MS spectra. In addition, untargeted analyses for each beverage were performed with a platform combining LC, ion mobility spectrometry and mass spectrometry (LC-IMS-MS) measurements. Approximately 300 features were observed across samples in the untargeted studies, and of these ~100 were identified. In vitro effects of energy drinks and some of their ingredients were then tested in iPSC-derived cardiomyocytes. Data on the beat rate (positive and negative chronotropy), ion channel function (QT prolongation), and cytotoxicity were collected in a dilution series. We found that some of the energy drinks elicited adverse effects on the cardiomyocytes with the most common being an increase in the beat rate, while QT prolongation was also observed at the lowest concentrations. Finally, concentration addition modeling using quantitative data from the 6 common ingredients and multivariate prediction modeling was used to determine potential ingredients responsible for the adverse effects on the cardiomyocytes. These analyses suggested theophylline, adenine, and azelate as possibly contributing to the in vitro effects of energy drinks on QT prolongation in cardiomyocytes.

"Comparison of cardiovascular autonomic activity (heart rate variability and baroreceptor sensitivity) in young healthy females during fasting and hyperglycaemia"

BACKGROUND AND AIM

The present study compared cardiovascular autonomic activity and reactivity during fasting (FS) and hyperglycemia (HS) states in young healthy females.

METHODS

This case crossover study was conducted on 30 females recruited by convenient sampling. Blood glucose levels were measured in FS and after oral glucose load i.e., HS. Finger arterial blood pressure (BP) and ECG were recorded constantly to monitor baroreceptor sensitivity (BRS) and heart rate variability (HRV). Autonomic reactivity was tested with deep breathing (DB), Valsalva manoeuvre (VM), and head-up-tilt (HUT) test under FS and HS. HRV parameters not normally distributed were natural log (ln) transformed.

RESULTS

Significantly reduced Valsalva ratio and higher heart rate and BP were observed in HS that continued during HUT (P < 0.05). The lnSDNN (standard deviation of normal-to-normal intervals) and lnRMSSD (root mean square of successive differences) were significantly lower (p < 0.05) in HS during HUT. After HUT, lnRMSSD remained lower (P = 0.031), whereas lnLF/HF (low frequency/high frequency power) ratio (P = 0.042) and LFnu (normalized units) (P = 0.024) were higher in HS. BRS was significantly lower in supine position in HS compared to FS and further reduced in HUT position in both FS and HS (P < 0.05).

CONCLUSION

Compared to FS, the HS exhibited heightened sympathetic activity with attenuation of parasympathetic activity and this phenomenon was further accentuated by HUT. BRS was more sensitive indicator of autonomic effects of hyperglycemia in resting state. In addition to standard tests, autonomic reactivity in vulnerable young subjects could be useful to detect autonomic imbalance at an early stage.

Risk assessment of energy drinks with focus on cardiovascular parameters and energy drink consumption in Europe

To assess the possible cardiovascular risks associated with energy drink (ED) consumption in Europe, a comprehensive literature research was performed in regard to (i) possible ED-induced dose-dependent cardiovascular outcomes, (ii) ED consumption patterns in Europe and (iii) the risks of EDs in combination with alcohol. The identified intervention studies primarily investigated acute ED effects in young healthy adults. Moderate consumption of EDs corresponding to an acute caffeine intake of up to 200 mg did not result in clinically relevant cardiovascular changes in young healthy adults. However, high intake of EDs (about 1 L) was associated with moderate to severe adverse effects in some participants (i.a. prolonged QTc interval, palpitations). Studies have indicated that on some occasions, a substantial proportion of ED consuming children and adolescents (12% in 16 EU Member States) drink EDs in high quantities (≥1 L). This could pose a possible health risk to this group since adverse effects by such high ED consumption have been observed already in young healthy adults. Among further measures that might be considered to minimize this identified risk, policy makers could develop information and educational programs with the aim of raising public awareness.