The effects of acute energy drink consumption on the cardiovascular system of university students

Abstract

Introduction: Among the changes in dietary behaviour in South Africa is the increased consumption of energy drinks (EDs), shown to affect the cardiovascular system (CVS) due to high caffeine and bioactive compound concentrations. Cardiovascular disease (CVD) is a concern, especially in black cohorts with a reported high prevalence of hypertension, as increased consumption highlights the adverse effects of EDs on the CVS. Aim: This study’s aim was to determine the effects of acute ED exposure on the CVS of generally healthy, black, male university students. Methodology: A randomised, controlled, cross-over study was conducted on 26 male students aged between 18-29 years. A Monster® carbonated ED (intervention) and a diluted fruit juice concentrate with carbonated water (placebo) were administered to participants in a single-blinded manner on two non-consecutive days. Heart rate (HR; bpm) and blood pressure (BP; mmHg) were measured twice on the left arm of participants using an automated BP monitor. Measurements were recorded at 0-; 10-; 30-; 60-; 90-; and 120-minutes. Questionnaires were used to obtain demographical data and assess ED and caffeine usage. Results: Self-reported consumption frequency for caffeinated beverages was predominantly ≥14 servings/week (50%). The reported purpose for caffeine consumption was attributed to mainly academic purposes (61.5%). The preferred caffeinated beverage was EDs (77%). For ED consumption relative to baseline, systolic and diastolic BP were higher from 30-minutes (p<0,001 and p=0,015, respectively), HR was reduced at 10-minutes (p=0,015), while pulse pressure and MAP were increased from 30-minutes (p=0,043 and p<0,001). Following placebo consumption, blood pressure remained stable relative to baseline with BP reaching maximum values at 120-minutes. Although overall HR dropped below baseline in both groups over the study period, HR increased much later in the placebo group compared to the ED group, reaching its lowest point at 90-minutes, which in contrast, was the peak time point for ED consumption. For ED consumption relative to the placebo, BP was higher at all time points from baseline (p<0,001), while HR showed a significant increase at 90-minutes (p<0,001). Pulse pressure and MAP were higher for ED consumption, with significance observed at 90-minutes (p<0,001) for pulse pressure, and at all time points for MAP. The study found that drink type had a significant effect on BP (p<0,001) and a partial significance on HR (p=0,052). The interaction between drink type and time points had a significant effect on systolic BP v (p<0,001) and MAP (p<0,001) and a partial significance on diastolic BP (p=0,057). Conclusion: EDs significantly increased BP over a period of 2-hours relative to the placebo. These observations can be attributed to the sympathomimetic actions of the bioactive contents of EDs, especially as a result of the synergy between caffeine and taurine. Heart rate decreased slower in the ED group versus the placebo group which presented more stability. These changes can be attributed to caffeine’s stimulatory effects as well as its half-life in an adult body.

Inleiding: Die verhoogde inname van energiedrankies (ED’s) maak deel uit van Suid Afrikaners se dieet. Daar is bevind dat ED’s vanweë hulle hoë kaffeïeninhoud en bioaktiewe verbinding konsentrasies die kardiovaskulêre stelsel (KVS) affekteer. Kardiovaskulêre siektes is veral onder swart mense rede tot kommer gesien die nadele wat die verhoogde inname van ED’s vir die KVS inhou. Oogmerk: Die oogmerk van hierdie studie was om vas te stel watter uitwerking ’n akute inname van ED’s op die KVS van gesonde swart manlike universiteitstudente het. Metodologie: Altesame 26 manlike studente tussen 18 en 29 jaar het aan hierdie ewekansige, beheerde oorkruisstudie deelgeneem. ’n Monster®-ED (ingryping) en ’n vrugtesapkonsentraat verdun met sodawater (plasebo) is op twee nieopeenvolgende dae volgens die enkelblindmetode aan deelnemers toegedien. Hulle hartklop (HK; bpm) en bloeddruk (BD; mmHg) is twee keer met ’n geoutomatiseerde sfigmomanometer aan die linkerarm gemeet. Meterlesings is na 0; 10; 30; 60; 90 en 120 minute aangeteken. Deelnemers se demografiese data en inname van ED’s en kaffeïen is met behulp van vraelyste bepaal. Bevindings: Die self-gerapporteerde innamefrekwensie van kaffeïendrankies was oorwegend ≥14 porsies/week (50%). Volgens die deelnemers het ’n hoë kaffeïeninname hulle beter laat studeer (61,5%). ED’s was hulle gunstelingkaffeïendrankie (77%). Vir die inname van ED met betrekking tot die aanvangsmeting was die sistoliese en diastoliese BD ná 30 minute hoër (p<0,001 en p=0,015 onderskeidelik), HK ná 10 minute stadiger (p=0,015), terwyl polsdruk en gemiddelde arteriële druk (GAD) ná 30 minute hoër (p=0,043 en p<0,001). Vir ED inname met betrekking tot die plasebo was BD op alle metingstye hoër as die aanvangsmeting (p<0,001) en was HK ná 90 minute beduidend hoër (p<0,001). Polsdruk en GAD was hoër ná ED-inname. Beduidendheid is veral vir polsdruk ná 90 minute (p<0,001) en vir GAD op alle metingstye waargeneem. Die studie het bevind dat die soort drankie ’n beduidende effek op BD (p<0,001) en ’n gedeeltelike beduidende effek op HK gehad het (p=0,052). Die wisselwerking tussen die soort drankie en die metingstye het ’n beduidende effek op sistoliese BD (p<0,001) en GAD (p<0,001), maar ’n gedeeltelike beduidendheid op diastoliese BD (p=0,057) gehad. Gevolgtrekking: ED’s het BD met betrekking tot die plasebo oor ’n tydperk van twee uur beduidend laat styg. Ofskoon HK gedaal het, was waardes vir ED hoër met betrekking tot die plasebo. Hierdie waarnemings kan toegeskryf word aan die vasostimulant en simpatomimetiese werking van die bioaktiewe inhoud van ED’s as gevolg van veral die sinergie tussen kaffeïen en tourien.

Intshayelelo: Phakathi kweenguqu ezenzekileyo eMzantsi Afrika kwindlela yokutya kukunyuka kokusetyenziswa kweziselo ezinika amandla (iziselo ezinika Amandla,EDs), eziboniswa zichaphazela inkqubo yemithambo yentliziyo (CVS) ngenxa ye-khafini (caffeine) eninzi kunye nomxube oyingqumbululu wezinto ezisebenzayo (bioactive). Isifo semithambo yentliziyo (CVD) yinkxalabo, ngakumbi kumaqela abantu abamnyama, njengoko ukwanda kokusetyenziswa kuveza imiphumo emibi yeziselo ezinika amandla (ED) kwimithambo yentliziyo (CVS). Injongo: Injongo yolu phononongo yayikukuveza imiphumo yeziselo ezinika amandla eziyingozi kwinkqubo yemithambo yentliziyo (CVS) kubafundi abangamadoda abantsundu baseyunivesithi abasempilweni ngokubanzi.Indlela. yokwenza: Uphononongo olulawulwe ngokungakhethiyo olunqamlezileyo lwenziwe kubathathi nxaxheba abaneminyaka ephakathi kwe-18 kunye ne-29. I-Monster® isiselo esinika Amandla esinekharbon (carbonated ED) (ungenelelo) kunye nengqumbululu yencindi engxengiweyo kunye namanzi anekharbon (i-placebo) inikezelwe kubathathi nxaxheba ngendlela eyodwa kwiintsuku ezimbini ezingalandelelaniyo. Isantya sokubetha kwentliziyo (HR; bpm) kunye noxinzelelo lwegazi (BP; mmHg) zilinganiswe kabini kwingalo yasekhohlo yabathathi-nxaxheba kusetyenziswa isixhobo esizihambelayo i-sphygmomanometer. Imilinganiselo yarekhodwa kwi-0; 10; 30; 60; 90 kunye 120 yemizuzu. Imibuzo yayisetyenziselwa ukufumana idatha yabantu bendawo ethile ngokwamanani neemeko zabo kunye nokuhlola i-ED (iziselo ezinika Amandla) kunye nokusetyenziswa kwe-khafini (caffeine). Iziphumo: Izihlandlo zokusetyenziswa njalo kweziselo ezinekharbon ubukhulu becala zazine ≥14 ngokokuphaka / ngeveki (50%). Ukusetyenziswa kwekhafini kwabalelwa kwiinjongo zemfundo (61.5%). Esona siselo sikhethwayo esinekhafini yayiyisiselo esinika amandla i-EDs (77%). Ukusetyenziswa kwesiselo esinika amandla (ED) ngokuthelekswa nesiseko, uxinzelelo lwegazi xa intliziyo iqala ukumpompa igazi (systolic BP) kunye noxinzelelo lwegazi xa intliziyo iyeka ukumpompa igazi (diastolic BP) zaziphezulu ukusuka kwimizuzu engama-30 (p<0,001 kunye ne-p=0,015, ngokulandelanayo), i-santya sokubetha kwentliziyo (HR) yehla kwimizuzu eli-10 (p=0,015), ngelixa uxinzelelo lokubetha kwentliziyo kunye ne-MAP zonyuka ukusuka kwimizuzu engama-30 (p=0,043 kunye ne p<0,001). ix Ukusetyenziswa kwe-ED ngokuthelekiswa nento efaniswa neyeza kodwa elingelilo esetyenziselwa ekukholiseni nje (placebo), unxinzelelo lwegazi (BP) lwaluphezulu kuzo zonke indawo ukusuka kwisiseko (p<0,001), ngelixa isantya sokubetha kwentliziyo (HR) kubonise ukunyuka okukhulu kwimizuzu engama-90 (p<0,001). Uxinzelelo lokubetha kwentliziyo (Pulse) kunye ne-MAP zaziphezulu ekusebenziseni iziselo ezinika amandla (ED), zabonakala kakhulu kwimizuzu engama-90 (p<0,001) yoxinzelelo lokubetha kwentliziyo(pulse), kwaye kuzo zonke iindawo ze-MAP. Uphononongo lufumanise ukuba uhlobo lwesiselo lunento oluyenzayo ebonakalayo kuxinzelelo lwegazi (BP) (p<0,001) kwaye lwabonisa okuyinxalenye kwisantya sokubetha kwentliziyo (HR) (p=0,052). Ukusebenzisana phakathi kohlobo lwesiselo kunye neendawo zexesha kunefuthe olubonakalayo kuxinzelelo lwegazi xa intliziyo liqala ukumpompa igazi (systolic) (p<0,001) kunye ne-MAP (p<0,001), kunye nokuyinxalenye kuxinzelelo lwegazi xa iyekile ukumpompa igazi (diastolic) (p=0,057). Isiphelo: I-EDs (Iziselo ezinika Amandla) zinyuse kakhulu unxinzelelo lwegazi (BP) kwixesha elimalunga neyure ezi-2 kuthelekiswa nento efaniswa neyeza kodwa elingelilo esetyenziselwa ekukholiseni nje (placebo). Nangona isantya sokubetha kwentlinziyo (HR) sisehla, amaxabiso ayephezulu kwiziselo ezinika amandla (ED) ngokumalunga nento efaniswa neyeza kodwa elingelilo esetyenziselwa ekukholiseni nje (placebo). Olu qwalaselo lunokuthi lubalelwe kwizenzo zesivuseleli i-vaso kunye nechiza ukuvelisa iziphumo zokusebenza kophawu lwenkqubo yemithambo-luvo enovelwano ngokukhuthaza ukuvuselela imizwa yovelwano. yomthamo we-bioactive kwiziselo ezinika Amandla (EDs), ngakumbi ngenxa yokuhambelana phakathi kwe khafini (caffeine) kunye nezinto ezimuncu ezisetyenziselwa ukunika amandla kwiziselo i-taurine