Elevated sympathetic nerve activity plays a role in hyperinsulinemia, insulin resistance, obesity and cardiovascular disease.
Problems associated with PCOS include elevated levels of testosterone (the 'male' hormone found in both sexes), ovarian cysts, irregular menstrual cycles and infertility.
The study also found that the electro-acupuncture treatments led to more regular menstrual cycles, reduced testosterone levels and reduced waist circumference.
Exercise had no effect on the irregular or non-existent menstrual cycles that are common among women with PCOS, nor did it reduce waist circumference. However, exercise did lead to reductions in weight and body mass index.
"The findings that low-frequency electro-acupuncture and exercise decrease sympathetic nerve activity in women with PCOS indicates a possible alternative non-pharmacologic approach to reduce cardiovascular risk in these patients," said one of the researchers, Dr. Elisabet Stener-Victorin of the University of Gothenburg, Sweden.
The study has been published in the online edition of the American Journal of Physiology-Regulatory, Integrative and Comparative Physiology.