Naturalistically observed interpersonal problems and diabetes management in older adolescents and young adults with type 1 diabetes.

OBJECTIVE: This study investigated the links between naturalistically observed and self-reported interpersonal problems, diabetes management, and glucose levels in older adolescents and young adults with type 1 diabetes. DESIGN: Sixty-eight older adolescents and young adults (aged 17-20 years) participated in a cross-sectional study that consisted of three home visits and a daily diary segment. MAIN OUTCOME MEASURES: Participants wore the Electronically Activated Recorder (EAR) for four days to capture interpersonal problems and wore a continuous glucose monitor for blood glucose levels. Researchers also collected HbA1c values, conducted an interview to assess diabetes management, and collected participant-reported severity of interpersonal problems. RESULTS: High EAR-observed interpersonal problems were associated with poor diabetes management. Multiple regression analyses revealed that high EAR-observed interpersonal problems continued to explain variance in poor diabetes management after including self-reported interpersonal problems and covariates. CONCLUSION: These findings corroborate literature suggesting that negative interactions are associated with type 1 diabetes management. This study is the first to use the EAR to capture naturalistically observed interactions in this population and identify its utility beyond self-reports. These findings highlight the importance of considering naturalistically observed interactions when developing interventions to promote better diabetes management in older adolescents and young adults.

Effects of daily peer problems on sleep and the severity of pediatric asthma symptoms.

OBJECTIVE: Although psychosocial stressors in the home environment place children at risk for physical health problems, less is known about whether or how peer stressors contribute to health problems in youth. The current study investigated associations between daily peer problems and asthma symptoms among adolescents with asthma. The possible mediating role of nightly sleep disturbance and the moderating role of adolescent mental health were also examined. METHOD: Adolescents (N = 297) with asthma reported on peer problems, nighttime awakenings, sleep quality, and asthma symptoms over 4 days. Youth also self-administered daily peak expiratory flow rate (PEFR) assessments, and parents reported on their children's anxious-depressive symptoms. RESULTS: Adolescents encountering more daily peer problems experienced more severe asthma symptoms, but not lower PEFR. Mediation analyses demonstrated that associations between daily peer problems and subjective asthma symptoms were partially explained by more nighttime awakenings and lower sleep quality, even after accounting for potentially confounding demographic factors and adolescents' daily experiences of familial stress. However, these indirect pathways did not vary depending on youth anxious-depressive symptoms. CONCLUSIONS: The findings provide novel evidence for everyday peer stress as a developmentally relevant health risk factor among adolescents with asthma. Insofar as daily peer problems were associated with elevated asthma symptoms via impaired sleep, psychosocial interventions focusing on the peer context may help mitigate maladaptive health behaviors and asthma morbidity. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Childhood Socioeconomic Status and Cardiometabolic Health: A Test of the John Henryism Hypothesis in African American Older Adults.

BACKGROUND: John Henryism (JH) is a form of active high-effort coping. Low-socioeconomic status (SES) African Americans adopting JH to deal with structural racism and other chronic stressors might be more likely to display cardiovascular disease risk factors. Previous tests of this hypothesis have mostly focused on the moderating role of current SES and hypertension as the outcome variable. Furthermore, most of the previous work has been conducted among young and middle-aged adults. This study aimed at extending work on the JH hypothesis by testing the combined effect of JH and childhood SES on metabolic syndrome and systemic inflammation among African American older adults. METHODS: One hundred seventy urban African American older adults (Mage = 67.64 years, 75.9% female) were recruited. Participants completed questionnaires assessing JH, childhood SES, and other variables used as covariates (ie, demographic information, chronic conditions, medication use, and health behaviors). Blood pressure, waist circumference, and blood were also collected. Triglycerides, high-density lipoprotein cholesterol, hemoglobin A1C, and C-reactive protein levels were measured from the blood samples. RESULTS: JH was positively associated with metabolic syndrome symptoms among participants reporting low childhood SES levels, but not among those reporting high childhood SES levels. The same pattern did not emerge when we considered current SES. Similar patterns of results did not emerge as far as systemic inflammation was concerned. CONCLUSIONS: Our findings highlight the importance of considering the joint impact of objective conditions early in life and individual psychological proclivities in explaining increased risk for cardiovascular disease risk in this population.

Elevated Pediatric Chagas Disease Burden Complicated by Concomitant Intestinal Parasites and Malnutrition in El Salvador.

The eradication of the vector Rhodnius prolixus from Central America was heralded as a victory for controlling transmission of Trypanosoma cruzi, the parasite that causes Chagas disease. While public health officials believed this milestone achievement would effectively eliminate Chagas disease, case reports of acute vector transmission began amassing within a few years. This investigation employed a cross-sectional serosurvey of children either presenting with fever for clinical care or children living in homes with known triatomine presence in the state of Sonsonate, El Salvador. Over the 2018 calendar year, a 2.3% Chagas disease seroprevalence among children with hotspot clustering in Nahuizalco was identified. Positive serology was significantly associated with dogs in the home, older participant age, and a higher number of children in the home by multivariate regression. Concomitant intestinal parasitic infection was noted in a subset of studied children; 60% having at least one intestinal parasite and 15% having two or more concomitant infections. Concomitant parasitic infection was statistically associated with an overall higher parasitic load detected in stool by qPCR. Lastly, a four-fold higher burden of stunting was identified in the cohort compared to the national average, with four-fifths of mothers reporting severe food insecurity. This study highlights that polyparasitism is common, and a systems-based approach is warranted when treating Chagas disease seropositive children.

Perceived stress is linked to heightened biomarkers of inflammation via diurnal cortisol in a national sample of adults.

Exposure to and perceptions of stress have been associated with altered systemic inflammation, but the intermediate processes by which stress links to inflammation are not fully understood. Diurnal cortisol slopes were examined as a pathway by which self-reported psychosocial stress is associated with inflammation [i.e., C-reactive protein (CRP), interleukin-6 (IL-6), fibrinogen, E-Selectin, and Intercellular Adhesion Molecule-1 (ICAM-1)] in a large sample of adults (the Midlife in the US study; N = 914; 55.9% female; aged 34-84 years). Structural equation modeling indicated that perceived psychological stress was associated with flattened diurnal cortisol slopes and flatter diurnal cortisol slopes were, in turn, associated with heightened inflammation in these cross-sectional analyses (index of indirect pathway, ω = 0.003, 95% CI [0.001, 0.004], ωSTD = 0.027; with covariates, ω = 0.001, [0.0002, 0.002], ωSTD = 0.011). A similar indirect effect was evident for self-reported traumatic life events (ω = 0.007, [0.004, 0.012], ωSTD = 0.030); however, inclusion of covariates (i.e., age, gender, race, ethnicity, body mass index, and other factors associated with physical health) accounted for this finding (ω = 0.001, [-0.001, 0.004], ωSTD = 0.005). These results support an allostatic load model of psychosomatic health, in which cortisol (along with other stress-responsive signaling molecules) is a necessary component for understanding links between stress exposure, perceived stress, and immune functioning.

Correction to Rodriguez-Stanley et al. (2020).

Reports an error in "Housework, health, and well-being in older adults: The role of socioeconomic status" by Jacqueline Rodriguez-Stanley, María Alonso-Ferres, Samuele Zilioli and Richard B. Slatcher (Journal of Family Psychology, 2020[Aug], Vol 34[5], 610-620). In the article (http://dx.doi.org/10 .1037/fam0000630), values are incorrectly reported in columns 1-3 of Table 1 and in the "Eudaimonic well-being," "Physical health," and "Sleep dysfunction" columns of Table 2. Although the significance of the associations and analyses remain unchanged, the corrected table columns are included in the erratum. (The following abstract of the original article appeared in record 2020-09875-001.) For most adults, household chores are undesirable tasks yet need to be completed regularly. Previous research has identified absolute hours spent on household chores and one's perceived fairness of the housework distribution as predictors of romantic relationship quality and well-being outcomes. Drawing from the Equity Theory, we hypothesized that perceived fairness acts as an underlying psychological mechanism linking household chores hours to long-term effects of relationship quality, well-being, physical health, and sleep quality in a sample of 2,644 married and cohabiting adults from the Midlife Development in the U.S. study. Additionally, following the Reserve Capacity Model, socioeconomic status (SES) was tested as a moderator because of its association with exposure to stressors and psychological resources which contribute to perceived fairness. Moderated mediation results showed significant indirect effects of household chore hours through perceived fairness on prospective measures of well-being, marital quality, physical health, and sleep dysfunction among individuals of lower SES but not higher SES when controlling for age, sex, and paid work hours. These results highlight the importance of perceived fairness and the influence of SES in the links among household chores and long-term relationship processes, health, and well-being. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Socioeconomic status and differential psychological and immune responses to a human-caused disaster.

OBJECTIVE: Individuals from different socioeconomic status (SES) backgrounds may respond variably to stressful events, and such differences are likely to contribute to health disparities. The current study leveraged data collected before and after a petrochemical explosion and aimed to investigate how individuals from different SES backgrounds responded to this unexpected stressor in terms of perceived social support, perceived stress, and systemic inflammation. METHODS: Data were drawn from 124 participants (Mage = 55.9 ± 16.1 years, 69.4% female, 29.0% White) living close to a petrochemical complex where the explosion occurred in 2005. SES was assessed at baseline, and perceived stress and inflammatory markers (i.e., C-reactive protein [CRP], interleukin-6 [IL-6]) were assessed at both pre- and post-explosion. Perceived social support was assessed at post-explosion. RESULTS: Lower SES was associated with less perceived social support. Lower SES was also associated with a larger increase in perceived stress and higher levels of IL-6, but not CRP. Perceived social support did not moderate or mediate the effects of SES on changes in perceived stress, IL-6, or CRP. The associations between SES and inflammatory markers were also not explained by changes in perceived stress. CONCLUSION: Findings from this study support the idea that individuals from different SES backgrounds respond differently to stressors at both the psychosocial (perceived social support and perceived stress) and biological (inflammation) levels. Our findings also suggest that these two processes appear to act independently from each other.

Housework, health, and well-being in older adults: The role of socioeconomic status.

For most adults, household chores are undesirable tasks yet need to be completed regularly. Previous research has identified absolute hours spent on household chores and one's perceived fairness of the housework distribution as predictors of romantic relationship quality and well-being outcomes. Drawing from the Equity Theory, we hypothesized that perceived fairness acts as an underlying psychological mechanism linking household chores hours to long-term effects of relationship quality, well-being, physical health, and sleep quality in a sample of 2,644 married and cohabiting adults from the Midlife Development in the U.S. study. Additionally, following the Reserve Capacity Model, socioeconomic status (SES) was tested as a moderator because of its association with exposure to stressors and psychological resources which contribute to perceived fairness. Moderated mediation results showed significant indirect effects of household chore hours through perceived fairness on prospective measures of well-being, marital quality, physical health, and sleep dysfunction among individuals of lower SES but not higher SES when controlling for age, sex, and paid work hours. These results highlight the importance of perceived fairness and the influence of SES in the links among household chores and long-term relationship processes, health, and well-being. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Tegaserod in patients with mechanical sensitivity and overlapping symptoms of functional heartburn and functional dyspepsia.

BACKGROUND: While functional heartburn (FH) and functional dyspepsia (FD) are recognized clinical entities, symptoms often overlap across both disorders. Despite their frequency, little is known of the underlying pathophysiology of overlapping symptoms. This study evaluated the effect of the 5-HT(4) agonist, tegaserod, on visceral sensitivity and symptom improvement in patients with overlapping symptoms of FH and FD. RESEARCH DESIGN AND METHODS: Patients with overlapping symptoms of FH and FD (ROME II) and mechanical hypersensitivity (Barostat examination) were randomized to tegaserod 6 mg bid or placebo for 2 weeks with treatment crossover after a 2-week washout period. Esophageal and gastric Barostat sensory tests were performed and patients rated their overall symptoms at study end. When carry-over was detected, data were presented for period 1 only. Safety was also assessed. RESULTS: Sixty patients were screened of whom 30 were randomized and 25 completed. Mechanical hypersensitivity was reported by 83% of 47 patients completing esophageal and gastric baseline Barostat examinations. Tegaserod did not significantly alter balloon volume to pain (primary variable); however, pressure to gastric pain increased (p = 0.044 vs. placebo). The severity of heartburn, regurgitation, early fullness, and bloating was significantly lower following tegaserod vs. placebo treatment (p = 0.026, p = 0.021, p = 0.016, and p = 0.030). Overall symptom improvement was reported by 52% tegaserod vs. 32% placebo patients (p = 0.275), and treatment was well tolerated. CONCLUSIONS: Results suggest that tegaserod may increase the gastric pain threshold and decrease the severity of individual symptoms in patients with overlapping FH and FD. However, these findings must be considered within the context of the study limitations, including the small number of subjects, potential for and presence of a carry-over effect, along with the impact of Barostat balloon use on the assessment of gastric function.

Effect of esophageal acid and prophylactic rabeprazole on performance in runners.

INTRODUCTION: Acid reflux occurs during exercise. The effects of esophageal acid and prophylactic antisecretory treatment on exercise performance are unknown. AIMS: To determine 1) the effect of esophageal acid perfusion during exercise on pulmonary function and exercise performance, and 2) whether acid suppression with rabeprazole (RAB) 20 mg x d(-1) increases exercise performance during esophageal acid infusion. METHODS: This was a two-phase study. Twenty-four conditioned runners (11 with heartburn, 13 without) completed phase 1. Sixteen runners with heartburn completed phase 2 (RAB). For phase 1, esophageal evaluation, baseline maximum exertion test, and a standard Bruce protocol maximal stress test were performed. Runners were randomized to sham esophageal infusion (NG tube placed in the distal esophagus, no fluid) or esophageal acid perfusion (0.1 N HCl perfused) during exercise. Subjects were crossed over to the alternate perfusion. For phase 2, runners underwent three sessions with both acid and sham perfusion during running; the sessions were randomly conducted on different days at baseline and 8 and 12 wk of RAB 20 mg. RESULTS: For phase 1, esophageal function and sensitivity were normal. There was no difference in airway resistance or work capacity between groups. The acid-perfusion group significantly decreased time to exhaustion in the no-heartburn group (23.13 to 20.66 min) with a decrease in energy expenditure. For phase 2, time to exhaustion was significantly decreased with acid perfusion at all time points (P < 0.05). Total energy expenditure during exercise was less in each acid-perfusion test. No difference in pulmonary function was present at week 12 versus baseline. CONCLUSIONS: Esophageal acid perfusion decreased performance. In runners with heartburn, suppression of endogenous acid secretion did not improve exercise performance. Changes in cardiopulmonary function do not explain the decreased exercise performance during acid perfusion.

Effect of naproxen on gastric acid secretion and gastric pH.

BACKGROUND: The mechanisms for the non-steroidal anti-inflammatory drug-induced inflammation in the stomach are unclear. AIMS: To determine if naproxen (Naprosyn, Roche, Nutley, NJ, USA) alters basal acid output, pentagastrin-stimulated maximal acid output, or fasting gastrin. METHODS: Basal acid output and maximal acid output gastric aspirations were performed pre-naproxen and 7 days post-naproxen 500 mg b.d. in 24 healthy subjects. Volume, pH and acid mEq were determined. Fasting gastrin was obtained. Comparisons were made using paired t-tests (alpha = 0.05). RESULTS: Dosing with naproxen did not statistically decrease mean pH of the basal acid output gastric fluid (3.3 vs. 3.1; N.S.) or the pentagastrin-stimulated maximal acid output gastric fluid (2.7 vs. 2.6; N.S.). Basal acid output total volume was significantly decreased post-naproxen (84 vs. 61 mL/h; P = 0.01), with no change in maximal acid output total volume (196 vs. 188 mL/h; N.S.). Basal acid output mean gastric acidity was significantly increased post-naproxen (0.04 vs. 0.05 mEq/mL; P = 0.03), with no change in maximal acid output mean gastric acidity after naproxen (0.10 vs. 0.10; N.S.). Gastrin was not altered by dosing with naproxen. CONCLUSIONS: Naproxen does not influence total acid secreted but does decrease basal gastric fluid volume, thereby increasing basal gastric acid concentration. These observations define one mechanism by which non-steroidal anti-inflammatory drugs may induce gastric injury.

Effect of tegaserod on esophageal pain threshold, regurgitation, and symptom relief in patients with functional heartburn and mechanical sensitivity.

BACKGROUND & AIMS: Tegaserod, a 5-HT4-receptor partial agonist, effectively treats irritable bowel syndrome with constipation. The role of tegaserod in functional disorders of the upper gastrointestinal (GI) tract is unclear. The aims of this study were to determine if tegaserod improves esophageal pain with mechanical and chemical stimuli, GI symptom profile, and global preference in patients with functional heartburn. METHODS: Patients with functional heartburn, as defined by Rome II criteria, underwent esophageal barostat and acid-infusion sensory tests. Mechanical hypersensitivity was required for entry. The baseline GI symptom profile was rated before treatment. Patients were blinded to treatment and randomly assigned to tegaserod 6 mg twice daily or placebo for 14 days, and crossed-over to the alternate treatment after 7 to 10 days of washout. Patients underwent sensory tests and rated GI symptoms after each treatment. Global treatment preference was completed at the end of the study. RESULTS: Forty-two patients (15 men, 27 women; age, 20-68 y) completed the study. The predominant baseline symptoms in addition to heartburn included upper-abdominal pain, upper-abdominal discomfort, regurgitation, chest pain, early satiety, and postmeal bloating. Tegaserod significantly increased balloon pressure to pain (P = .04) and the mean (P = .002) and maximum wall tension at pain (P = .0004). Tegaserod did not alter pain with acid infusion. Tegaserod significantly decreased the frequency of occurrence of heartburn/acid reflux (P = .004), regurgitation (P = .048), and distress from regurgitation (P = .039). The global preference for tegaserod was 63.4% vs 12.2% for placebo. CONCLUSIONS: Tegaserod improved the esophageal pain threshold to mechanical distention, and distressing upper-GI symptoms in patients with functional heartburn.

Esophageal visceral sensitivity to bile salts in patients with functional heartburn and in healthy control subjects.

Patients with nonerosive gastroesophageal reflux disease often have relatively low esophageal acid exposure and respond suboptimally to gastric acid suppression. In these patients, other constituents of gastric contents may induce esophageal symptoms. We have demonstrated that gastric contents can cause heartburn when the gastric pH >4. (Aliment Pharm Ther 14:129-134, 2000). The aim of this study was to determine relative sensitivities to chenodeoxycholic and ursodeoxycholic acids, and 0.1 N HCl, administered as provocative perfusion tests. Patients with functional heartburn and healthy control subjects were evaluated. Patients underwent a modified Bernstein acid infusion test and esophageal Barostat balloon distention. Time and volume to pain were recorded. Barostat balloon distention was performed using our standard protocol. Stepwise distentions were performed and pain was recorded. Sensitivity to chenodeoxycholic acid (Cheno) and Ursodeoxycholic acid (Urso) were assessed similarly to the Bernstein test using 2 mM concentrations of each, followed immediately by 5 mM if no pain was reported with 2 mM. Volume of bile acid infusion and length of time until pain was induced were assessed and compared to the same endpoints for acid sensitivity. "Total" time and "total" volume to induce pain were calculated for Cheno and Urso. Least-squares means were generated and two-tailed t-tests and regression analyses were performed (P < 0.05 level of significance). Ten functional heartburn patients and six healthy controls were evaluated (3 M, 13 F; age range, 19 to 56 years). Since five of six controls had pain with acid infusion (hypersensitive), all subjects were analyzed as one group. Only three subjects (all controls) had no pain with infusion of 2 mM Cheno and received the follow-up infusion of 5 mM. These same three subjects tolerated the maximum infusion (150 ml and 15 min) of 5 mM Cheno. Nine subjects did not have pain with 2 mM Urso and received the follow-up infusion of 5 mM Urso (five functional heartburn, four controls). Significantly more subjects tolerated the maximum bile acid infusion of 2 mM Urso vs 2 mM Cheno (nine vs three; P < 0.05, Chi-square test). The pain threshold (volume and time) for Urso was significantly higher than that for Cheno and acid (P < 0.05), and the pain threshold for Cheno was significantly higher than that for acid (P < 0.05). Conclusions are as follows: (1) Bile acids differ in their ability to induce pain. (2) Changing bile acid composition by treatment with Urso may change symptom presentation and symptom severity in patients with bile acid-induced esophageal pain.

A single dose of ranitidine 150 mg modulates oesophageal acid sensitivity in patients with functional heartburn.

BACKGROUND: The rapid onset and symptomatic response to histamine-2 receptor antagonists prior to the pharmacological effect on acid secretion suggests a different mechanism of action. AIM: To determine if ranitidine decreases oesophageal sensitivity to chemical and mechanical stimulation, potentially via oesophageal histamine receptors. METHODS: A total of 18 patients with functional heartburn received oral ranitidine 150 mg b.d. or placebo for 7 consecutive days in a double-blind randomized crossover design and underwent Barostat balloon distention and Bernstein acid infusion on study day 1 (90 min postdose) and study day 7. First sensation and pain were recorded and pain severity was rated on a 5-point Likert scale and a 100 mm visual analogue scale. Least square mean values were generated and one-tailed t-tests were performed. RESULTS: After a single dose of ranitidine 150 mg, time to pain with oesophageal acid infusion was increased by 29% (P < 0.05) and visual analogue scale and Likert scores were decreased by 20% (P < 0.06) and 23% (P < 0.02), respectively compared with placebo. After 1 week of ranitidine, positive alterations in sensory parameters persisted. Balloon distention sensory parameters were not altered by ranitidine. CONCLUSIONS: Ranitidine significantly decreased oesophageal sensitivity to acid. Failure of ranitidine to improve balloon sensory parameters supports existence of multiple sensory pathways in the oesophagus.

Calcium carbonate antacids alter esophageal motility in heartburn sufferers.

Chewed calcium carbonate (CaCO3) rapidly neutralizes esophageal acid and may prevent reflux, suggesting another mechanism of action independent of acid neutralization. Calcium is essential for muscle tone. Our aim was to determine if luminal calcium released from chewed antacids improved esophageal motor function in heartburn sufferers. Esophageal manometry and acid clearance (swallows and time to raise esophageal pH to 5 after a 15-ml 0.1 N HCl bolus) were performed in 18 heartburn sufferers before and after chewing two Tums EX (1500 mg CaCO3, 600 mg calcium). Subjects with hypertensive esophageal contractions or hypertensive lower esophageal sphincter pressure (LESP) were excluded. Subjects with normal to low LESP were included. Differences between parameters were determined by two-tailed paired t-tests, P < 0.05. Proximal esophageal contractile amplitude was significantly increased after CaCO3 (47.18 vs 52.97 mm Hg; P = 0.02), distal onset velocity was significantly decreased after CaCO3 (4.34 vs 3.71 cm/sec; P = 0.02), and acid clearance was significantly increased 30 min after CaCO3 (20.35 vs 11.7 swallows, [P < 0.005] and 12.19 vs 6.29 min [P < 0.007]). LESP was not altered after CaCO3 (22.70 vs 23.79 mm Hg; P = 0.551), however, LESP increased in 9 of 18 subjects. Depth of LES relaxation, medial and distal esophageal contractile amplitude, and duration of contractions were not altered by CaCO3. CaCO3 did not alter salivary secretion and pH in a subset of these subjects, and CaCO3 with secreted saliva did not neutralize a 15-ml acid bolus. The Ca2+ released after chewing of CaCO3 antacids may be partially responsible for the reduction of heartburn by significantly improving initiation of peristalsis and acid clearance.

Esophageal reflux in conditioned runners, cyclists, and weightlifters.

INTRODUCTION: Gastroesophageal reflux disease is a disorder in which gastric contents move from stomach to esophagus. Exercise is a recognized contributing factor to reflux in healthy volunteers and is reported to be proportional to exercise intensity and the type of exercise. Our aim was to explore changes in physiology occurring in conditioned runners, cyclists, and weightlifters. METHODS: Ten subjects from each sport with >3-month history of exercise-induced heartburn were enrolled. Subjects underwent evaluation of fasting and fed esophageal pH, heart rate, GI symptom, and perceived exertion during standardized exercise routines at 65% (60 min) and 85% (20 min) of their maximal capabilities. RESULTS: Weightlifters experienced the most heartburn and reflux: 18.51 +/- 17.34% time esophageal pH

Clinical effectiveness of a new antacid chewing gum on heartburn and oesophageal pH control.

BACKGROUND: Oesophageal acid neutralization with antacids depends on the duration of oesophageal antacid exposure and acid neutralizing capacity. A gum that releases antacid as it is chewed could take advantage of both mechanisms to enhance heartburn relief. METHODS: Twenty-four subjects were crossed over to four regimens: placebo, chewable antacid tablets (1000 mg CaCO3), lower dose gum (600 mg CaCO3) and higher dose gum (900 mg CaCO3). A dual pH probe was placed, subjects ate a standardized provocative meal and self-dosed once as needed. Symptoms were recorded every 15 min using visual analogue and Likert scales. SYMPTOMS: Both gums decreased heartburn compared to placebo for 120 min. Higher dose gum decreased heartburn more than chewable antacids up to 120 min post-dose. pH: Active chewable antacid and gums immediately increased oesophageal pH, with significant improvement 15-30 min post-dose. SUMMARY: (i) both gums promptly decreased heartburn and elevated oesophageal pH; (ii) both gums provided sustained relief for 120 min; (iii) antacid gums provided faster and more prolonged symptom relief and pH control than chewable antacids. CONCLUSIONS: Calcium carbonate gum effectively neutralizes oesophageal acidity and relieves symptoms following a meal, and is superior to chewable antacids in terms of the duration of heartburn relief.

Cisapride inhibits meal-stimulated gastric acid secretion and post-prandial gastric acidity in subjects with gastro-oesophageal reflux disease.

BACKGROUND AND AIMS: KCNQ1 potassium channels in human gastric parietal cells are thought to be involved in gastric acid secretion. As cisapride can inhibit similar channels in other tissues and is an effective treatment for nocturnal heartburn, we examined the effects of cisapride on gastric and oesophageal acidity, gastric emptying and heartburn severity in subjects with gastro-oesophageal reflux disease. METHODS: Subjects (n = 11) had suffered from heartburn four times or more per week for at least 6 months. Gastric pH and oesophageal pH were measured before, during and after a standard meal ingested over 15 min. Each subject received placebo or 10 mg cisapride orally, 30 min before the beginning of the meal. Meal-stimulated gastric acid secretion was calculated from the amount of HCl required to titrate the homogenized standard meal to pH 2 in vitro and the time required for the pH of the ingested meal to decrease to pH 2 in vivo. Heartburn severity was assessed at 15-min intervals beginning at the end of the meal. Gastric emptying of solids was measured using a [(13)C]-octanoic acid breath test. RESULTS: Cisapride significantly decreased meal-stimulated gastric acid secretion by 20%, decreased integrated gastric and oesophageal acidity by 50-60% and transiently increased the expiration of (13)CO(2). Cisapride did not significantly alter heartburn severity. CONCLUSIONS: The cisapride-induced decreases in meal-stimulated gastric acid secretion, gastric acidity and oesophageal acidity in subjects with gastro-oesophageal reflux disease can account for its beneficial clinical effects. These results also raise the possibility that gastric KCNQ1 potassium channels are important in meal-stimulated gastric acid secretion and possibly in the pathophysiology of gastro-oesophageal reflux disease.

Effects of antacid formulation on postprandial oesophageal acidity in patients with a history of episodic heartburn.

BACKGROUND: Heartburn self-treatment with antacids is extremely common. If the oesophagus is the primary site of antacid action, chewable antacids might raise the oesophageal pH more effectively than swallowable tablets. AIM: To establish a model to assess postprandial acid reflux and to compare the onset and duration of action on oesophageal pH of different antacid formulations. METHODS: Twenty subjects with a history of episodic heartburn underwent eight pH monitoring sessions each for 5.5 h postprandially. One hour after consuming a meal consisting of chili, cheese, raw onions and cola, subjects received 750 mg, 1500 mg and 3000 mg of either chewable or swallowable CaCO3 tablets, an effervescent bicarbonate solution or placebo. Oesophageal and gastric pH data were collected. RESULTS: Mean intra-oesophageal pH remained lower than baseline for more than 1 h (pH range 5-5.5) postprandially, indicating reflux of somewhat acidic intragastric contents into the oesophagus. The onset of action on oesophageal pH was similar for all antacids (30-35 min). The duration of action on pH varied: chewable tablets and effervescent bicarbonate had relatively long durations of action (oesophagus, 40-45 min; stomach, 100-180 min); swallowable tablets had little effect. CONCLUSIONS: The meal model used in this study dependably produced acidic gastro-oesophageal reflux. Antacids increased oesophageal pH independent of gastric pH, demonstrating that chewing antacids controls oesophageal acidity more effectively than swallowing antacid tablets.

Integrated acidity and rabeprazole pharmacology.

BACKGROUND: Integrated gastric and oesophageal acidity can be calculated from measurements of gastric and oesophageal pH and used to quantify gastric and oesophageal acidity over time. Rabeprazole is a new proton pump inhibitor that is effective in treating gastro-oesophageal reflux disease (GERD). AIM: To use measurement of integrated gastric and oesophageal acidity to determine the onset, duration and overall effect of rabeprazole in subjects with GERD. METHODS: Subjects with GERD were required to have oesophageal pH less-than-or-equal 4 for at least 10% of a 24-h recording. Effects of 20 mg rabeprazole on 24-h gastric and oesophageal pH were measured on days 1 and 7 of dosing. Integrated gastric and oesophageal acidity were calculated from time-weighted average hydrogen ion concentrations at each second of the 24-h record. RESULTS: At steady-state, 20 mg rabeprazole inhibited gastric acidity by 89% and oesophageal acidity by 95%. The first dose of rabeprazole inhibited gastric and oesophageal acidity by at least 70% of the steady-state effect. Oesophageal acidity could be divided into monophasic and biphasic patterns, and rabeprazole had different effects on oesophageal and gastric acidity in these two GERD subpopulations. The onset of action of the first dose of rabeprazole on gastric acidity was 4 h and on oesophageal acidity was 4 h in monophasic subjects and 7 h in biphasic subjects. Integrated acidity was more sensitive than time pH less-than-or-equal 4 in measuring the inhibitory actions of rabeprazole. CONCLUSIONS: Integrated gastric and oesophageal acidity are quantitative measurements that provide useful and novel information regarding the pathophysiology of GERD as well as the impact of antisecretory agents such as rabeprazole.