A 1-μT extremely low-frequency electromagnetic field vs. sham control for mild-to-moderate hypertension: a double-blind, randomized study

• Published in: Hypertension research Vol. 34; no. 3; pp. 372 - 377
• Main Authors: Nishimura, Tsutomu, Tada, Harue, Guo, Xinfeng, Murayama, Toshinori, Teramukai, Satoshi, Okano, Hideyuki, Yamada, Junichi, Mohri, Kaneo, Fukushima, Masanori
• Format: Journal Article
• Language: English
• Published: England 01.03.2011
• Subjects: Aged; Blood Pressure - physiology; Double-Blind Method; Female; Hand - physiopathology; Humans; Hypertension - therapy; Magnetic Field Therapy; Male; Middle Aged; Paresthesia - etiology; Treatment Outcome
• ISSN: 0916-9636; 1348-4214
• DOI: 10.1038/hr.2010.246

The effects of extremely low-frequency electromagnetic fields (ELF-EMFs) on blood pressure (BP) are controversial. In this double-blind, randomized, sham-controlled study, we examined the effects of repeated exposure to a 1-μT ELF-EMF on BP in 20 humans with mild-to-moderate hypertension. Subjects were randomly assigned to either the ELF-EMF group or the sham group. Subjects in the ELF-EMF group were exposed to an ELF-EMF (6- and 8 Hz, respectively, peak magnetic field 1 μT, peak electric field 10 Vm(-1)) for at least two 10- to 15-min sessions per week, over a period of 4 weeks. In the sham group, the EMF-generating apparatus was not active. We obtained systolic and diastolic BP (SBP and DBP, respectively) measurements at registration and before and after each ELF-EMF exposure session. Subjects in the ELF-EMF and sham groups had mean ages of 52.8 and 55.1 years, and were exposed to a mean of 9.9 and 9.0 sessions, respectively. There was a significant difference between the ELF-EMF and sham groups with respect to change in SBP value between baseline and the end of the exposure regimen (P=0.02), but not with respect to change in DBP (P=0.21). There were no adverse events other than mild paresthesia of the hands of two subjects in the ELF-EMF group. Our results suggest that repeated exposure to an ELF-EMF has a BP-lowering effect on humans with mild-to-moderate hypertension.