Hormones and pain – a “rebirth”

Does extracorporeal shock wave lithotripsy-related pain get affected by menstrual cycle and menopause?

The objective of the study was to investigate the effect of the menstrual cycle and menopause on extracorporeal shock wave lithotripsy (ESWL)-related pain outcome. Since March 2017, we evaluated a total of 145 women who underwent the first session of ESWL for renal or ureteral stones. Patients were divided into two groups, as menstruating and menopaused women. For menstruating women, the number of days between the last day of mens and ESWL was noted and women were separated as in the follicular phase (1-14 days) or in the luteal phase (15-30 days) of menstruation. To control these two female groups, 149 men of similar age were included in the study. After the procedure, the experienced pain was recorded on a ten-point visual analog scale (VAS) by the patient and they also rated the severity of pain as no, mild, tolerable, and intolerable on the pain questionnaire. The mean age of the patients was 43 ± 15 years for the female group and 42 ± 13 years for the male group. While stone burden was not different between the female and male groups (p = 0.459), VAS score was not statistically different between genders (p = 0.293). However, men reported a higher rate of mild pain, while women reported a higher rate of tolerable pain (p = 0.008) in the pain questionnaire. Mean VAS score was significantly lower for the menopaused women group than menstruating women, young and old men (p = 0.001). In a subgroup analysis, menopaused women group reported lower VAS score and better pain questionnaire result than menstruating women (p < 0.001). There was no statistically significant difference between the follicular and luteal phase of the menstrual cycle in terms of mean VAS score and pain questionnaire results (p = 0.891 and 0.441, respectively). When compared with the young men group, the only significant difference was pain questionnaire results between women in the luteal phase (p = 0.014). Multiple regression analysis showed that only menstruation (β = 0.639, p < 0.001) was an independent factor for VAS score. Menstrual cycle phase had no effect on pain perception during the ESWL session and menopaused women felt less pain than menstruating women during this procedure. The control male group showed that the reduction of ESWL-related pain in menopause was not related to aging.

Relationship between pubertal timing and chronic nonspecific pain in adolescent girls: the Young-HUNT3 study (2006-2008)

The aim of this study was to examine a possible relationship between early puberty and chronic nonspecific pain in 13- to 18-year-old girls. All adolescents in Nord-Trøndelag County, Norway, were invited to participate in the Young-HUNT3 study (2006-2008). Of the invited girls, 81% answered the questionnaire and of these 3982 were 13 to 18 years of age. Menarche and perceived physical maturation were used as exposure measures. Early menarche was defined as <12 years, normal menarche as ≥12 and <14 years, and late menarche as ≥14 years. Perceived physical maturation was divided into maturing earlier, the same or later than others of their own age. The main outcome measure was chronic nonspecific pain, defined as pain in at least one location not related to any known disease or injury, for at least once a week during the last 3 months. The median age at menarche was 13.2 years. Chronic nonspecific pain was more prevalent among girls with early menarche (68%, 95% CI: 64%-72%) compared to girls with either normal (55%, 95% CI: 53%-57%), late (50%, 95% CI: 46%-54%), or no menarche (35%, 95% CI: 29%-40%). The association persisted after adjusting for age, body mass index, socioeconomic factors, and anxiety and depression. A similar association was found between girls that perceived themselves as earlier physically matured than their peers and chronic nonspecific pain. Headache/migraine was the most common type of chronic nonspecific pain regardless of menarcheal age. In all reported locations, pain was more prevalent in the group with early menarche compared to normal or late menarche.

"Luteal Analgesia": Progesterone Dissociates Pain Intensity and Unpleasantness by Influencing Emotion Regulation Networks

Background: Pregnancy-induced analgesia is known to occur in association with the very high levels of estradiol and progesterone circulating during pregnancy. In women with natural ovulatory menstrual cycles, more modest rises in these hormones occur on a monthly basis. We therefore hypothesized that the high estradiol high progesterone state indicative of ovulation would be associated with a reduction in the pain experience. Methods: We used fMRI and a noxious thermal stimulus to explore the relationship between sex steroid hormones and the pain experience. Specifically, we assessed the relationship with stimulus-related activity in key regions of networks involved in emotion regulation, and functional connectivity between these regions. Results: We demonstrate that physiologically high progesterone levels are associated with a reduction in the affective component of the pain experience and a dissociation between pain intensity and unpleasantness. This dissociation is related to decreased functional connectivity between the inferior frontal gyrus and amygdala. Moreover, we have shown that in the pre-ovulatory state, the traditionally "male" sex hormone, testosterone, is the strongest hormonal regulator of pain-related activity and connectivity within the emotional regulation network. However, following ovulation the traditionally "female" sex hormones, estradiol and progesterone, appear to dominate. Conclusions: We propose that a phenomenon of "luteal analgesia" exists with potential reproductive advantages.