Background and Aims: To understand pathophysiological mechanisms underlying migraine as a cardiovascular risk factor, we studied neuropeptide action and endothelial function as measures of peripheral microvascular function in middle-aged women with or without migraine., Methods: We included women with the endocrine disorder polycystic ovary syndrome (PCOS), a population with supposed elevated cardiovascular risk, with and without comorbid migraine. In 26 women without and 23 women with migraine in the interictal phase (mean age 50.8 ± 2.9 years) local thermal hyperemia (LTH) of the skin of the volar forearm was measured cross-sectionally under control conditions, after inhibition of neuropeptide release by 5% lidocaine/prilocaine (EMLA) cream application, and after inhibition of nitric oxide formation by iontophoresis of NG-monomethyl-l-arginine (L-NMMA). Hereafter, changes in the natural logarithm of the reactive hyperemia index (lnRHI) and augmentation index (AI) during reperfusion after occlusion-derived ischemia were measured., Results: While mean values under control conditions and L-NMMA conditions were similar, migraine patients had a significantly higher mean area of the curve (AUC) of the total LTH response after EMLA application than those without (86.7 ± 26.5% versus 67.9 ± 24.2%; p = 0.014). This was also reflected by a higher median AUC of the plateau phase under similar conditions in women with migraine compared to those without (83.2% (IQR[73.2-109.5]) versus 73.2% (IQR[54.3-92.0]); p = 0.039). Mean changes in lnRHI and AI scores were similar in both groups., Conclusions: In PCOS patients with migraine, neuropeptide action was lower compared with those without migraine. While larger studies are warranted, these findings provide a potential mechanism supporting previous findings that migraine may be independent from traditional risk factors, including atherosclerosis., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Linda Al-Hassany, Katie M. Linstra, Cindy Meun, Jeffrey van den Berg, Eric H. Boersma, A.H. Jan Danser, and Joop S. Laven declares no conflict of interest with respect to the research, authorship, and/or publication of this article. Bart C.J.M. Fauser has received fees, or grant support over the most recent 4 year period from the following organisations (in alphabetic order); Bain Capital, Controversies in Obstetrics & Gynecology (COGI), Dutch Heart Foundation (Nederlandse Hartstichting), Elsevier, European Society of Human Reproduction and Embryology (ESHRE), Ferring, International Federation of Fertility Societies (IFFS), London Womens Clinic, Myovant, Netherlands Organisation for Health Research and Development (ZonMw), Pantharei Bioscience, Partners Group, PregLem/Gideon Richter, Shieldler, Reproductive Biomedicine Online (RBMO), UpToDate. Marieke J.H. Wermer is supported by the Dutch Research Council (Aspasia grant and ZonMw/NWO, Vidi Grant 91717337). Gisela M. Terwindt reports consultancy or industry support from Novartis, Lilly and Teva, Allergan/Abbvie, and Lundbeck and independent support from the European Community, Dutch Heart Foundation, IRRF, Dioraphte, and Dutch Brain Council. Further, she received independent support from the Dutch Research Council (849200007), Dutch Brain Foundation (HA2017.01.05), and support from Alnylam and Biogen. The latter two companies contribute to a consortium that funds the running costs of a natural history study on D-CAA. Antoinette Maassen Van Den Brink received research grants and/or consultation fees from Allergan, Amgen/Novartis, Eli Lilly, Teva and ATI, and was supported by the Dutch Research Council (ZonMw/NWO, Vici Grant 09150181910040)., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)