Menstrual pain, also known as dysmenorrhea, is a debilitating disorder that affects over 50% of women in the United States. Dysmenorrhea is also a leading risk factor for the development of chronic pelvic pain conditions such as bladder pain syndrome (BPS). We hypothesized that abnormal autonomic cardiac activity, which is associated with psychological distress and chronic pain states, may contribute to the transition from dysmenorrhea to bladder pain syndrome. We tested our hypothesis by assessing heart rate variability in healthy controls, dysmenorrheic participants, and BPS participants in their luteal phase across a drinking-induced bladder fill.
In our published manuscript (Sci Rep. 2019 Feb 18;9(1):2194.) we found that both dysmenorrheic and BPS participants reported increased bladder pain sensitivity when compared to healthy controls. We also found that dysmenorrheic and BPS participants exhibited increased heart rate and reduced heart rate variability when compared to healthy controls at baseline and during bladder filling. A post-hoc correlation analysis revealed that heart rate was associated with self-reported menstrual pain, but not bladder pain sensitivity or psychological factors. Overall, the findings of this manuscript suggest that mechanisms underlying dysmenorrhea are impactful enough to alter autonomic cardiac activity and increased bladder pain sensitivity, even during the luteal phase. This manuscript is the first of its kind to examine the effects of natural bladder filling on autonomic function in dysmenorrheic participants during their luteal phase.