Chakraborty, Subhankar

AbstractBackgroundThe relationship between cardiovascular and gastrointestinal (ie, plasma pancreatic polypeptide [PP] response to modified sham feeding [MSF]) indices of vagal function is unclear. Hyperglycemia inhibits PP secretion via vagally mediated mechanisms. Our aims were to (a) compare the PP response, (b) its relationship with glycemia, and (c) the relationship between PP response to MSF, gastric emptying (GE) of solids, and symptoms during GE study in healthy controls, patients with diabetic gastroenteropathy (DM), and non‐ulcer dyspepsia (NUD).MethodsIn 24 healthy controls, 40 DM, and 40 NUD patients, we measured plasma PP concentrations during MSF, cardiovagal functions, GE, and symptoms during a GE study.Key ResultsBaseline PP concentrations were higher in DM than in controls and NUD (P = .01), and in type 2 than in type 1 DM patients (P < .01). The PP increment during MSF was normal (≥20 pg/mL) in 70% of controls, 54% of DM, and 47% of NUD patients. Overall, the PP response and cardiovagal tests were concordant (P = .01). Among patients with a reduced PP increment with MSF, 7/10 of T1DM and 1/7 of T2DM patients had moderate or severe cardiovagal dysfunctions (P < .05). The PP response to MSF was not associated with GE.Conclusions & InferencesUp to 30% of healthy controls have a reduced PP increment during MSF, limiting the utility of this test to detect vagal injury. The PP response is more useful when it is normal than abnormal. A reduced PP response is more likely to be associated with cardiovagal dysfunctions in T1DM than in T2DM.

AbstractBackgroundOur aim is to explain the lack of clarity in the ways in which anxiety and depression, which are common in defecatory disorders (DD), may contribute to the disorder. In this study, we evaluate the effects of mental stress and relaxation on anal pressures and the mechanisms thereof.MethodsIn 38 healthy women and 36 DD patients, rectoanal pressures were assessed at rest and during mental stressors (ie, word‐color conflict [Stroop] and mental arithmetic tests) and mental relaxation, before and after randomization to placebo or the adrenergic α1‐antagonist alfuzosin.Key ResultsDuring the baseline Stroop test, the anal pressure increased by 6 ± 13 mm Hg (mean ± SD, P = 0.004) in healthy women and 9 ± 10 mm Hg (P = 0.0001) in constipated women. During mental arithmetic, the anal pressure increased in healthy (4 ± 8 mm Hg, P = 0.002) and constipated women (5 ± 9 mm Hg, P = 0.004). After relaxation, anal pressure declined (P = 0.0004) by 3 ± 4 mm Hg in DD patients but not in controls. Alfuzosin reduced (P = 0.0001) anal resting pressure (by 31 ± 19 mm Hg) vs placebo (16 ± 18 mm Hg). However, during the postdrug Stroop test, anal pressure increased (P = 0.0001) in participants who received alfuzosin but not placebo.Conclusions & InferencesIn healthy controls and DD patients, mental stressors likely increased anal pressure by contracting the internal anal sphincter; relaxation reduced anal pressure in DD patients. Alfuzosin reduced anal resting pressure but did not block the Stroop‐mediated contractile response, which suggests that this response is not entirely mediated by adrenergic α1 receptors.