Study from Evidence Based Complementary and Alternative Medicine September 22, 2009 done by a Taiwanese group (http://ecam.oxfordjournals.org/cgi/content/full/nep145v1) looks at obesity in postmenopausal women. They evaluated the effect of Transcutaneous Electric Acupoint Stimulation (TEAS) as a function of body composition and heart rate variability. Body composition was used as a screening test (percentage body fat >30%, waist >80cm.) The study group received TEAS twice a week for 30 minutes for 12 weeks. The control group did not receive any intervention. HRV and body composition was measured at the 4th,8th, and 12th week. Waist circumference and % body fat were significantly less than those of the control group at the 8th and 12th week. HRV increased as measured by SDNN from the 4th to the 8th week, but was no different from controls at the 12th week.
They conclude that TEAS treatment improves body composition and has a transient effect on the HRV in postmenopausal women with obesity.

Unfortunately, there was no sham TENS applied, so this is not a truly controlled study. But this study, nonetheless, raises some interesting questions. First of all, TENS is a therapy that could be applied by patients at home, which could be an incredibly convenient therapeutic help to people afflicted with obesity. It is very interesting that the HRV increased with TENS treatment, and it is impossible to know if the HRV improved because of body composition changes or vice versa. I will look forward to further studies to see if this effect can be corroborated. It should also be noted that the subjects weight did not change, only their lean mass.