The Influence of Menstrual Phases on Pain Modulation in Healthy Women

• Published in: The journal of pain Vol. 13; no. 7; pp. 646 - 655
• Main Authors: Rezaii, Taraneh, Hirschberg, Angelica Lindén, Carlström, Kjell, Ernberg, Malin
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.07.2012
• Subjects: Adult; Anesthesia & Perioperative Care; Blood pressure; Blood Pressure - physiology; Female; gonadal steroid hormones; Humans; masseter muscle; Medicin och hälsovetenskap; menstrual cycle; Menstrual Cycle - physiology; Menstrual Cycle - psychology; Pain - physiopathology; Pain - psychology; Pain Measurement; Pain Medicine; pain modulation; Pain Perception - physiology; Pain Threshold - physiology; Physical Stimulation; Women's Health; Blood pressure; gonadal steroid hormones; masseter muscle; menstrual cycle; pain modulation
• ISSN: 1526-5900; 1528-8447; 1528-8447
• DOI: 10.1016/j.jpain.2012.04.002

Abstract This study investigated if conditioned pain modulation (CPM) varies across the menstrual cycle in healthy, normally menstruating women and investigated correlations between sex hormone levels and CPM across the menstrual cycle. Thirty-six normally menstruating women were tested during 3 phases of the menstrual cycle: early follicular, ovulatory, and midluteal, confirmed by hormone determinations. Mechanical pressure (test stimulus) was applied to the masseter muscle and the induced pain assessed before, during, and after immersion of the hand into ice water (conditioning stimulus) to activate CPM or tepid water (control). Conditioning pain, ie, pain in the hand during CPM/control experiment, and tolerance time were also measured. Test pain intensity was suppressed during CPM in all phases ( P < .001), but with more effective suppression during the ovulatry than during the early follicular phase ( P < .05). There were no changes in test pain intensity during the control experiment and no significant differences in conditioning pain, or tolerance time between phases. In conclusion, our results showed more effective pain modulation in the ovulatory phase of the menstrual cycle, when estradiol levels are high and progesterone levels are low, than in the early follicular phase when both these hormones are low. Perspective Deficient pain modulation is believed to be an important pathogenic factor in many chronic pain conditions that affect women. This article shows that sex hormones modulate conditioned pain modulation, because pain inhibition was more effective in the ovulatory phase of the menstrual cycle than in the early follicular phase.