Electrocardiographic and hemodynamic effects of a multicomponent dietary supplement containing ephedra and caffeine: a randomized controlled trial.

What Was Tested

The paper reports a study of Caffeine and Ephedra, published as a randomized controlled trial.

To determine the impact of the DSEC on corrected QT (QTc) interval duration and systolic blood pressure (SBP).

Why It Was Studied

Metabolife 356, a multicomponent dietary supplement containing ephedra and caffeine (DSEC) in addition to several other components, is the top-selling dietary weight loss supplement.

Given its common use, anecdotal reports of cardiovascular and cerebrovascular adverse events, and paucity of safety data, further research with this DSEC was warranted.

Who Took Part

PubMed indexes the participants as adults, both men and women.

How the Study Was Run

The design is described as randomized, double-blind, placebo-controlled and crossover.

The participants were allocated by chance, so the Caffeine group and the comparison group should start out alike.

As a double-blind Caffeine study, the assignments were hidden from both participants and investigators until the end.

Some participants received a placebo instead of Caffeine, giving a reference point.

In the crossover set-up each of the participants took both Caffeine and the comparison in turn, acting as their own control.

Randomized, double-blind, placebo-controlled, crossover study conducted from January to May 2003.

What Was Measured

Topics PubMed links to this paper include Blood Pressure, Caffeine, Dietary Supplements, Electrocardiography, Ephedra, Heart and Heart Rate.

What This Means in Plain Language

The paper is a randomized, double-blind and placebo-controlled study of Caffeine and Ephedra.

Its findings take up roughly 6 sentences of the abstract and are left out here on purpose; the source paper is the place to read them.

The publication is from 2004 (JAMA), a journal based in United States.

More context: all human trials.