Persistent autonomic dysfunction and bladder sensitivity in primary dysmenorrhea

Abstract

Menstrual pain, also known as dysmenorrhea, is a leading risk factor for bladder pain syndrome (BPS). A better understanding of the mechanisms that predispose dysmenorrheic women to BPS is needed to develop prophylactic strategies. Abnormal autonomic regulation, a key factor implicated in BPS and chronic pain, has not been adequately characterized in women with dysmenorrhea. Thus, we examined heart rate variability (HRV) in healthy (n = 34), dysmenorrheic (n = 103), and BPS participants (n = 23) in their luteal phase across a bladder-filling task. Both dysmenorrheic and BPS participants reported increased bladder pain sensitivity when compared to controls (p’s < 0.001). Similarly, dysmenorrheic and BPS participants had increased heart rate (p’s < 0.01), increased diastolic blood pressure (p’s < 0.01), and reduced HRV (p’s < 0.05) when compared to controls. Dysmenorrheic participants also exhibited little change in heart rate between maximum bladder capacity and after micturition when compared to controls (p = 0.013). Our findings demonstrate menstrual pain’s association with abnormal autonomic activity and bladder sensitivity, even two weeks after menses. Our findings of autonomic dysfunction in both early episodic and chronic visceral pain states points to an urgent need to elucidate the development of such imbalance, perhaps beginning in adolescence.

Small Fiber Polyneuropathy May Be a Nexus Between Autonomic Nervous System Dysregulation and Pain in Interstitial Cystitis/Bladder Pain Syndrome

“…It is also notable that at baseline prior to their operation, these patients did not have differences in HR or BP measurements compared to controls. These findings contrast with results from several groups that reported resting HR and BP are higher in those with IC/BPS (25)(26)(27).…”

“…The vagus nerve (parasympathetic) is responsible for decreasing the speed of the heart rate, while sympathetic tone increases the speed of the heart and raises blood pressure. Therefore, it is notable that those with IC/BPS have been found to have an elevated resting heart rate ( 25 , 26 ) and diastolic blood pressure ( 26 ) at rest. Elevations in resting heart rate (without blood pressure changes) have also been seen prior to, while undergoing, and after undergoing a variety of mental stress models and was unrelated to perceived stress changes ( 27 ).…”

Impact of Endometriosis on Life-Course Potential: A Narrative Review

“… 8 In another study, abnormal autonomic activity was identified in women with dysmenorrhea even 2 weeks after menses. 13 These studies highlight the importance of understanding how chronic pain develops and how to treat it. 8 , 13 Additionally, a British study of 1671 reproductive-aged women found that of the 24% of women with CPP, 11% also reported dysmenorrhea, 1.4% reported dyspareunia (painful intercourse), and 8% reported all three conditions.…”

“… 13 These studies highlight the importance of understanding how chronic pain develops and how to treat it. 8 , 13 Additionally, a British study of 1671 reproductive-aged women found that of the 24% of women with CPP, 11% also reported dysmenorrhea, 1.4% reported dyspareunia (painful intercourse), and 8% reported all three conditions. 14 Women with CPP had lower scores in QoL related to physical and mental health and greater sleep-related difficulties (eg, difficulty falling asleep or staying asleep) compared with the women who had dysmenorrhea only.…”

“…[10][11][12] Furthermore, women with dysmenorrhea may be at a higher risk of developing CPP-related conditions like bladder pain syndrome, which may further negatively impact a patient's life course. 13 Results from one recent study indicated that women with dysmenorrhea who also experience comorbid bladder pain hypersensitivity may be at an even greater risk for developing chronic pain. 8 In another study, abnormal autonomic activity was identified in women with dysmenorrhea even 2 weeks after menses.…”