Hypoalgesia related to elevated resting blood pressure is absent in adolescents and young adults with a history of functional abdominal pain

Abstract

Elevated resting blood pressure (BP) is hypoalgesic in healthy individuals, but this effect is absent in adults with chronic somatic pain. This study tested whether BP-related hypoalgesia is similarly altered in individuals with a history of chronic visceral pain in childhood. Resting BP was assessed in 94 adolescents and young adults with a known history of childhood functional abdominal pain (FAP) and 55 comparable healthy controls. Responses to an acute heat pain stimulus were then evaluated following exposure to two laboratory stressors. A significant Participant Type X Systolic BP (SBP) interaction (p<.005) revealed that elevated resting SBP was associated with significantly higher heat pain threshold (p<.001) in healthy controls, but was unrelated to pain threshold in the FAP group. A similar pattern was observed for heat pain tolerance, with elevated SBP linked to significantly higher pain tolerance (p<.05) in healthy controls, but unrelated to tolerance in the FAP group. Dysfunction in BP-related hypoalgesia associated with FAP was evident regardless of whether childhood FAP had resolved or still persisted at the time of laboratory testing. Subgroup analyses indicated that BP-related hypoalgesia (in healthy controls) and FAP-linked absence of this hypoalgesia was observed only among females. Result suggest that childhood visceral chronic pain may be associated with relatively long-lasting dysfunction in overlapping systems modulating pain and BP that persists even after FAP resolves. Potential implications for later hypertension risk are discussed.

Is Resolution of Chronic Pain Associated With Changes in Blood Pressure-related Hypoalgesia?

“…Participants were recruited from a sample participating in a large prospective study of adolescents and young adults with childhood functional abdominal pain [25][26][27]. Participants from the original study had presented to the Vanderbilt Pediatric Gastroenterology Clinic for evaluation of chronic abdominal pain when they were 8-16 years old.…”

“…A key issue that has not yet been adequately addressed is whether chronic pain-related alterations in BP-hypoalgesic mechanisms remain altered even after the chronic pain resolves. A preliminary, post hoc test of this issue in our past work was confounded by failure to control for comorbid nonabdominal chronic pain in many participants [25].…”

“…In work related to this study, we examined whether BP-related hypoalgesia for static evoked pain measures was altered in adolescents and young adults who had been diagnosed with functional abdominal pain (FAP), on average, 9 years earlier compared to similar individuals without any chronic pain history [25]. Results suggested a significant impairment of BP-analgesic mechanisms only for those who had been diagnosed with chronic functional abdominal pain in childhood.…”

“…To address this gap in the literature and build upon our prior work [25][26][27], in this study, we examined the effect of resolution of chronic pain on BP-related hypoalgesic mechanisms as they relate to responses to both static and dynamic evoked pain stimuli. Specifically, we compared young adults with a known childhood history of functional abdominal pain in whom the condition had resolved versus not resolved at the time of testing, regarding the associations between resting BP and thermal pain threshold, tolerance, and temporal summation.…”

Blood Pressure and Heart Rate Response to Posteriorly Directed Pressure Applied to the Cervical Spine in Young, Pain-Free Individuals: A Randomized, Repeated-Measures, Double-Blind, Placebo-Controlled Study

“…Within both groups, there was a small but statistically significant reduction in systolic BP following the procedure. 3 There is also some evidence that cardiovascular response is affected by manual therapy.…”