CAN CONTROLLED BREATHING LOWER BP?
Could you comment on RESPeRATE, which advertises itself as the “breakthrough medical device clinically proven to lower high BP with no side effects”?
—Gerard K. Nash, DO, Amarillo, Tex.
The theory behind RESPeRATE is that slowing the breathing rate for 10 or 15 minutes a day can yield persisting effects on sympathetic tone. There are few physiologic data to explain or back up this hypothesis. A few studies have been published, but the results must be interpreted cautiously.
In a well-controlled trial, eight weeks of RESPeRATE therapy (n=47) lowered self-monitored home BP by 5/3 mm Hg, vs. a decrease of 2/1 in the control group (n=26), a difference of only 3.5/2.2 mm Hg (Am J Hypertens. 2004;17:370-374). This is a rather small effect. Interestingly, the baseline BP of the treatment group was significantly higher than that of the control group at entry (141/88 vs. 133/86) and obviously still higher at the end of the study, casting further doubt concerning the results.
In another study, ambulatory BP monitoring of 20 patients revealed a fall in BP of 7/2 mm Hg after RESPeRATE treatment (Am J Hypertens. 2001;14:74-76). However, there was no control group for comparison!
A third study found that office BP fell 15/10 mm Hg among 32 treated subjects vs. 11/6 among the 29 control subjects (who listened to music on a Walkman every day), a difference of 4/4 mm Hg (J Hum Hypertens. 2001;15:271-278). The study’s main weakness is that neither home BP nor ambulatory BP was assessed. Once again, the treatment group had a slightly higher entry BP. The end-of-study BP of the two groups was the same (141/87 in the RESPeRATE group vs. 143/88 in the Walkman group).
The effect of RESPeRATE is at best small, and the data thus far reported do not inspire tremendous confidence. I do not believe this technology offers a breakthrough.
—Samuel J. Mann, MD (114-9)