Acute effects of energy drink on hemodynamic and electrophysiologic parameters in habitual and non-habitual caffeine consumers.

BACKGROUND & AIMS: The consumption of energy drinks has significantly increased in recent years but their adverse effects are yet to be identified. The objective of the study is to determine the acute effects of energy drink on habitual and non-habitual caffeine consumers and if caffeine consumption habit causes a difference in the hemodynamic and electrophysiological responses. METHODS: We carried out a non-randomized, non-placebo controlled, three-arm parallel assignment with 48 students enrolled at Aydin Adnan Menderes University. Four main groups were determined according to the results of the application acceptance survey. Blood pressure, electrocardiogram, breath rate, haemoglobin oxygen saturation and bioelectrical impedance analysis were measured before consuming the drinks. After consuming the drinks, measurements were repeated at 30 min and 60 min. In addition, Participant's Situation Anxiety Scale was recorded. RESULTS: Energy drink consumption led to a significant increase in systolic blood pressure, diastolic blood pressure and heart rate for non-habitual caffeine consumers. PR interval and QRS complex were not affected significantly, however QTc interval reduced in time. Haemoglobin oxygen saturation and breathing rate did not change. Body fat percentage values of habitual energy drink consumers were smaller than the other groups. Body metabolism rate increased after energy drink consumption. There was no significant change for high-habitual caffeine consumers in all parameters evaluated. CONCLUSIONS: Energy drink consumption has a negative effect on hemodynamic parameters. But as the habituation level increases the impact of energy drink on hemodynamic parameters tends to decrease. CLINICALTRIALS REGISTRATION: Registered under ClinicalTrials.gov Identifier No: NCT04223167.

Maintenance of a Schwann-Like Phenotype in Differentiated Adipose-Derived Stem Cells Requires the Synergistic Action of Multiple Growth Factors.

Differentiating human adipose-derived stem cells (ASCs) towards Schwann cells produces an unstable phenotype when stimulating factors are withdrawn. Here, we set out to examine the role of glial growth factor 2 (GGF-2) in the maintenance of Schwann-like cells. Following ASC differentiation to Schwann-like cells, stimulating factors were withdrawn such that cells either remained in media supplemented with all stimulating factors, GGF-2 alone, or underwent complete withdrawal of all factors. Furthermore, each stimulating factor was also removed from the growth medium individually. At 72 hours, gene (qRT-PCR) and protein (ELISA) expression of key Schwann cell factors were quantified and cell morphology was analysed. Cells treated with GGF-2 alone reverted to a stem cell morphology and did not stimulate the production of brain-derived neurotrophic factor (BDNF), regardless of the concentration of GGF-2 in the growth medium. However, GGF-2 alone increased the expression of Krox20, the main transcription factor involved in myelination, relative to those cells treated with all stimulating factors. Cells lacking fibroblast growth factor were unable to maintain a Schwann-like morphology, and those lacking forskolin exhibited a downregulation in BDNF production. Therefore, it is likely that the synergistic action of multiple growth factors is required to maintain Schwann-like phenotype in differentiated ASCs.