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There is a broad literature indicating gender differences in cardiovascular heart diseases. However, gender differences in cardiovascular reactivity to experimental pain have revealed conflicting results. Therefore, we aimed to establish gender differences to experimental pain assessment in cardiovascular reactivity. Cardiovascular reactivity was measured by the change in Central Blood Pressure (CBP), Peripheral Arterial Stiffness (PAS), and Heart Rate Variability (HRV) before and after experimental pain assessment in 28 healthy subjects (12 males, age = 43.7046±6 years; 16 females, age= 49.31±7). CBP and PAS were determined non-invasively by pulse wave analysis (XCEL, SyphgmoCor). High-frequency (HF) and low-frequency (LF) bands were explored as a HRV parameter during each of the phases as an index of vagal cardiac control and sympathetic cardiac activation (MP-150, Biopac). Thermal stimuli were applied to the forearm by a contact thermode to assess thermal pain Tolerance. Repeated measures ANOVA showed a significant interaction term between gender and central diastolic blood pressure [F(1,25)=4.66, p=0.04], where males experienced a significantly steeper increase than females (males ΔCBP 11.35 mm Hg vs. females ΔCBP 2.21 mm Hg). The Central Augmented pressure and the AIX@HR75 (PAS indicators) increased significantly between baseline and pain tolerance with a significant main effect of gender, where females had a higher central augmented pressure and AIX@HR75 than males. No interaction term was observed between HRV variables and gender. These preliminary results imply that in general males have a higher cardiovascular reactivity due to pain induction than females. However, females showed larger PAS, which could produce a ceiling effect on their cardiovascular reactivity. Further studies in a larger sample and in patients with chronic pain could provide stronger evidence about the relationship between chronic pain and cardiovascular risk. [ABSTRACT FROM AUTHOR]

Shoulder surgery is a primary intervention for shoulder pain, yet many individuals experience persistent postoperative pain. Previously, we found individuals categorized as having a high-risk phenotype (comprised of COMT variation and pain catastrophizing) had approximately double the chance of not reaching a 12-month pain recovery criterion. As a means to better understand the development of persistent postoperative shoulder pain, this study advanced our previous work by examining temporal ordering of postoperative shoulder recovery based on potential mediating factors, and expansion of outcomes to include movement-evoked pain and shoulder active range of motion. Before surgery, individuals were categorized as either high-risk (high pain catastrophizing, COMT-genotype linked to low enzyme activity [n = 41]) or low-risk (low pain catastrophizing, COMT-genotype linked to normal enzyme activity [n = 107]). We then compared potential mediating variables at 3, 6, and 12 months postoperatively 1) endogenous pain modulation defined by a conditioned pain modulation paradigm; and 2) and emotion factors such as anxiety, fear of movement, and depressive symptoms. At 3 months, the high-risk subgroup had higher fear and movement-evoked pain, and causal mediation analysis confirmed the direct effect of risk subgroup on 12-month movement evoked pain. However, baseline to 12-month change in depressive symptoms were found to mediate 53% of the total effect of risk subgroup on 12-month movement-evoked pain. This study introduces potential temporal components and relationships to the development of persistent postoperative shoulder pain, which future studies will confirm and assess for potential therapeutic targets. PERSPECTIVE: This study expands upon postoperative shoulder recovery measures to include movement-evoked pain and depressive symptoms, and provides preliminary indication of temporal ordering to postoperative shoulder recovery for a preidentified high-risk subgroup. Future studies will distinguish temporal components of shoulder surgery that may optimize treatment targets of postoperative recovery., (Copyright © 2019 United States Association for the Study of Pain, Inc. Published by Elsevier Inc. All rights reserved.)

Unlabelled: Recent reports suggest deficits in conditioned pain modulation (CPM) and enhanced suprathreshold heat pain response (SHPR) potentially play a role in the development of chronic pain. The purpose of this study was to investigate whether central pain processing was altered in 2 musculoskeletal shoulder pain models. The goals of this study were to determine whether central pain processing: 1) differs between healthy subjects and patients with clinical shoulder pain; 2) changes with induction of exercise-induced muscle pain; and 3) changes 3 months after shoulder surgery. Fifty-eight patients with clinical shoulder pain and 56 age- and sex-matched healthy subjects were included in these analyses. The healthy cohort was examined before inducing EIMP, and 48 and 96 hours later. The clinical cohort was examined before shoulder surgery and 3 months later. CPM did not differ between the cohorts, however; SHPR was elevated for patients with shoulder pain compared to healthy controls. Induction of acute shoulder pain with EIMP resulted in increased shoulder pain intensity but did not change CPM or SHPR. Three months following shoulder surgery, clinical pain intensity decreased but CPM was unchanged from preoperative assessment. In contrast, SHPR was decreased and showed values comparable with healthy controls at 3 months. Therefore, the present study suggests that: 1) clinical shoulder pain is associated with measurable changes in central pain processing; 2) exercise-induced shoulder pain did not affect measures of central pain processing; and 3) elevated SHPR was normalized with shoulder surgery. Collectively our findings support neuroplastic changes in pain modulation were associated with decreases in clinical pain intensity only, and could be detected more readily with thermal stimuli., Perspective: Longitudinal studies involving quantitative sensory testing are rare. In exploring 2 musculoskeletal shoulder pain models (exercise-induced muscle pain and surgical pain), conditioned pain modulation was unchanged from pre- to post-assessment in both models. Suprathreshold heat pain response decreased after shoulder surgery and was comparable to healthy controls, suggesting this measure may be sensitive to decreases in clinical pain intensity., (Copyright © 2012 American Pain Society. Published by Elsevier Inc. All rights reserved.)

Unlabelled: Quantitative sensory testing (QST) has become commonly used for the assessment of pain in subjects with clinical conditions. However, there is no consensus about which type of QST is the best predictor of clinical pain responses. The purposes of this study were to determine: a) the QST measure with the strongest association with clinical pain intensity; and b) if the QST measure continued to predict clinical pain intensity in a model including relevant psychological factors. Fifty-nine patients seeking treatment for shoulder pain underwent experimental pain assessment involving heat and pressure stimuli. The patients also completed validated questionnaires for pain intensity, pain catastrophizing, anxiety, and depression. The 5th pain rating in a series of suprathreshold heat pain stimuli accounted for a significant amount of variance in clinical pain intensity, with no other QST measure contributing to the model. The 5th pain rating remained a significant contributor to clinical pain intensity when psychological factors were included in the model. Furthermore, subjects with elevated 5th pain rating, pain catastrophizing, and depression scores had higher clinical pain intensity ratings in pre- and postoperative assessments. These data suggest that assessment of pain should include suprathreshold heat stimuli and psychological factors separately, and a combination of these factors may be predictive of pain intensity outcomes., Perspective: The current study provides evidence for a suprathreshold heat pain response as a clinically relevant QST measure for patients with shoulder pain, even after psychological factors were considered. The present findings suggest that the 5th pain rating from a series of suprathreshold stimuli, pain catastrophizing, and depression might play a role in predicting pain intensity outcomes., (Copyright © 2011 American Pain Society. Published by Elsevier Inc. All rights reserved.)