RT Journal Article SR Electronic T1 Acupuncture or metformin to improve insulin resistance in women with polycystic ovary syndrome: study protocol of a combined multinational cross sectional case-control study and a randomised controlled trial JF BMJ Open JO BMJ Open FD British Medical Journal Publishing Group SP e024733 DO 10.1136/bmjopen-2018-024733 VO 9 IS 1 A1 Elisabet Stener-Victorin A1 Haolin Zhang A1 Rong Li A1 Cecilia Friden A1 Dong Li A1 Wei Wang A1 Haining Wang A1 Cuiqing Chang A1 Shi Li A1 ZeJun Huo A1 Hua Zhang A1 Xiaolan Ji A1 Angelica Linden-Hirschberg A1 Jie Qiao YR 2019 UL http://bmjopen.bmj.com/content/9/1/e024733.abstract AB Introduction Polycystic ovary syndrome (PCOS) is linked to hyperinsulinemia and insulin resistance with dysfunctional glucose metabolism. Pilot studies suggests that acupuncture treatment with combined manual and low-frequency electrical stimulation (electroacupuncture (EA)) of the needles decrease circulating glycated haemoglobulin (HbA1c) and homeostatic model assessment-insulin resistance. Therefore, we here aim to investigate if acupuncture treatment or metformin together with lifestyle or lifestyle management alone improves insulin sensitivity and related symptoms in overweight/obese women with PCOS.Methods and analysis This is a two-centre multinational (Sweden and China), cross-sectional case–control study combined with an open-labelled randomised controlled trial (RCT). Participants are randomised to one of three groups: (1) EA 2–3 times/week during 4 months+lifestyle management; (2) metformin, 500 mg, three/day during 4 months+lifestyle management; or (3) lifestyle management alone. The primary outcome measure in the RCT is changes in HbA1C. A total of 123 obese overweight women with PCOS will be enrolled and randomised into one of the three groups with a target power of at least 80% and 5% significance level based on two-sided tests.Ethics and dissemination The study has been approved by the Regional Ethical Review Board of Stockholm and of Peking University Third Hospital, China. Primary outcome data of the RCT will be published in a relevant journal together with supporting secondary outcome measurements. Further, outcome measurements will be published in separate papers as well as case–control data.Expected results We anticipate that EA and metformin, both with lifestyle management, are equally effective and superior to lifestyle management alone for improvement of glycaemic control.Trial registration numbers NCT02647827 and EudraCT2015-004250-18.