Effect of a selective personality-targeted prevention program on 7-year illicit substance related outcomes: A secondary analysis of a cluster randomized controlled trial

BACKGROUND

This study evaluated the efficacy of the selective personality-targeted PreVenture program in reducing cannabis and stimulant use over a 7-year period spanning adolescence and early adulthood.

METHODS

A cluster randomized controlled trial was conducted in 14 Australian schools. Schools were randomized to PreVenture, a brief personality-targeted selective intervention, comprising two 90-minute facilitator-led sessions delivered one week apart, or a control group (health education as usual). Only students who scored highly on one of four personality traits (anxiety sensitivity, negative thinking, impulsivity, sensation seeking) were included. Students completed online self-report questionnaires between 2012 and 2019: at baseline; post-intervention; 1-, 2-, 3-, 5.5- and 7-years post-baseline. Outcomes were past 6-months cannabis use, stimulant use (MDMA, methamphetamine or amphetamine) and cannabis-related harms.

RESULTS

The sample comprised 438 adolescents (Mage=13.4 years; SD=0.47) at baseline. Retention ranged from 51% to 79% over the 7-years. Compared to controls, the PreVenture group had significantly reduced odds of annual cannabis-related harms (OR=0.78, 95% CI=0.65-0.92). However, there were no significant group differences in the growth of cannabis use (OR=0.84, 95% CI=0.69-1.02) or stimulant use (OR=1.07, 95% CI=0.91-1.25) over the 7-year period.

CONCLUSIONS

PreVenture was effective in slowing the growth of cannabis-related harms over time, however owing to missing data over the 7-year trial, replication trials may be warranted to better understand the impact of the PreVenture intervention on cannabis and stimulant use among young Australians. Alternative implementation strategies, such as delivering the intervention in later adolescence and/or providing booster sessions, may be beneficial.

The long-term effectiveness of a personality-targeted substance use prevention program on aggression from adolescence to early adulthood

BACKGROUND

Addressing aggressive behavior in adolescence is a key step toward preventing violence and associated social and economic costs in adulthood. This study examined the secondary effects of the personality-targeted substance use preventive program Preventure on aggressive behavior from ages 13 to 20.

METHODS

In total, 339 young people from nine independent schools (M age = 13.03 years, s.d. = 0.47, range = 12-15) who rated highly on one of the four personality traits associated with increased substance use and other emotional/behavioral symptoms (i.e. impulsivity, anxiety sensitivity, sensation seeking, and negative thinking) were included in the analyses (n = 145 in Preventure, n = 194 in control). Self-report assessments were administered at baseline and follow-up (6 months, 1, 2, 3, 5.5, and 7 years). Overall aggression and subtypes of aggressive behaviors (proactive, reactive) were examined using multilevel mixed-effects analysis accounting for school-level clustering.

RESULTS

Across the 7-year follow-up period, the average yearly reduction in the frequency of aggressive behaviors (b = -0.42; 95% confidence interval [CI] -0.64 to -0.20; p < 0.001), reactive aggression (b = -0.22; 95% CI 0.35 to -0.10; p = 0.001), and proactive aggression (b = -0.14; 95% CI -0.23 to -0.05; p = 0.002) was greater for the Preventure group compared to the control group.

CONCLUSIONS

The study suggests a brief personality-targeted intervention may have long-term impacts on aggression among young people; however, this interpretation is limited by imbalance of sex ratios between study groups.

Adapting a coach-assisted web-based intervention for parents of adolescents who refuse school: qualitative study with users of the Partners in Parenting Plus programme

BACKGROUND

School refusal is a heterogenous problem which typically emerges in adolescence and co-occurs with internalising disorders. A substantial proportion of adolescents do not respond to existing treatment modalities; thus, novel, effective intervention options are needed. Partners in Parenting Plus (PiP+) is a coach-assisted, web-based intervention designed to empower parents to respond to adolescent internalising disorders.

AIMS

To conduct a process evaluation of PiP+ and identify programme adaptations required to meet the needs of parents of adolescents who refuse school.

METHOD

Semi-structured interviews were conducted with 14 Australian mothers who had: (a) received the PiP+ programme (not tailored for school refusal) during a prior research trial; and (b) reported that their adolescent was refusing school during their participation in PiP+. Inductive thematic analysis was used to analyse interview transcripts.

RESULTS

Participants were 41-53 years old (M = 47.8) and parenting adolescent children aged 14-17 years (M = 14.9). Three themes illustrated how PiP+ features met or could better meet the needs of parents of adolescents who were refusing school: (a) feeling heard, supported and respected; (b) relevance to me and my context; and (c) seeing positive changes. Participants had favourable views of PiP+, especially coached components. Participants requested programme enhancements to better meet the needs of parents of neurodiverse adolescents and discussed the impact of cumulative help-seeking 'failures' on self-efficacy and locus of control.

CONCLUSIONS

PiP+ was highly acceptable to the majority of parents navigating the issue of school refusal. This has implications for the enhancement of coach-assisted parenting interventions and the context-specific adaptation of PiP+ for school refusal.

Effect of Selective Personality-Targeted Alcohol Use Prevention on 7-Year Alcohol-Related Outcomes Among High-risk Adolescents: A Secondary Analysis of a Cluster Randomized Clinical Trial

IMPORTANCE

Alcohol consumption is one of the leading preventable causes of burden of disease worldwide. Selective prevention of alcohol use can be effective in delaying the uptake and reducing harmful use of alcohol during the school years; however, little is known about the durability of these effects across the significant transition from early adolescence into late adolescence and early adulthood.

OBJECTIVE

To examine the sustained effects of a selective personality-targeted alcohol use prevention program on alcohol outcomes among adolescents who report high levels of 1 of 4 personality traits associated with substance use.

DESIGN, SETTING, AND PARTICIPANTS

A cluster randomized clinical trial was conducted to assess the effectiveness of the selective personality-targeted PreVenture program on reducing the growth of risky alcohol use and related harms from early to late adolescence and early adulthood. Participants included grade 8 students attending 14 secondary schools across New South Wales and Victoria, Australia, in 2012 who screened as having high levels of anxiety sensitivity, negative thinking, impulsivity, and/or sensation seeking. Schools were block randomized to either the PreVenture group (7 schools) or the control group (7 schools). The primary end point of the original trial was 2 years post baseline; the present study extends the follow-up period from July 1, 2017, to December 1, 2019, 7 years post baseline. Data were analyzed from July 22, 2021, to August 2, 2022.

INTERVENTIONS

The PreVenture program is a 2-session, personality-targeted intervention designed to upskill adolescents to better cope with their emotions and behaviors.

MAIN OUTCOMES AND MEASURES

Self-reported monthly binge drinking, alcohol-related harms, and hazardous alcohol use measured by the Alcohol Use Disorders Identification Test-Concise consumption screener.

RESULTS

Of 438 participants (249 male [56.8%]; mean [SD] age, 13.4 [0.5] years) from 14 schools, 377 (86.2%) provided follow-up data on at least 2 occasions, and among those eligible, 216 (54.0%) participated in the long-term follow-up. Compared with the control condition, the PreVenture intervention was associated with reduced odds of any alcohol-related harm (odds ratio [OR], 0.81 [95% CI, 0.70-0.94]) and a greater mean reduction in the frequency of alcohol-related harms (β = -0.22 [95% CI, -0.44 to -0.003]) at the 7.0-year follow-up. There were no differences in the odds of monthly binge drinking (OR, 0.80 [95% CI, 0.56-1.13]) or hazardous alcohol use (OR, 0.87 [95% CI, 0.59-1.27]) at the 7.0-year follow-up. Exploratory analyses at the 5.5-year follow-up showed that compared with the control condition, the PreVenture intervention was also associated with reduced odds of monthly binge drinking (OR, 0.87, [95% CI, 0.77-0.99]) and hazardous alcohol use (OR, 0.91 [95% CI, 0.84-0.99]), but this was not sustained.

CONCLUSIONS AND RELEVANCE

This study demonstrated that a brief selective personality-targeted alcohol use prevention intervention delivered in the middle school years can have sustained effects into early adulthood.

TRIAL REGISTRATION

anzctr.org.au Identifier: ACTRN12612000026820.

The 7-Year Effectiveness of School-Based Alcohol Use Prevention From Adolescence to Early Adulthood: A Randomized Controlled Trial of Universal, Selective, and Combined Interventions

OBJECTIVE

Alcohol use is a leading cause of burden of disease among young people. Prevention strategies can be effective in the short-term; however little is known about their longer-term effectiveness. The aim of this study was to examine the sustainability of universal, selective, and combined alcohol use prevention across the critical transition period from adolescence into early adulthood.

METHOD

In 2012, a total of 2190 students (mean age, 13.3 years) from 26 Australian high schools participated in a cluster randomized controlled trial and were followed up for 3 years post baseline. Schools were randomly assigned to deliver the following: (1) universal Web-based prevention for all students (Climate Schools); (2) selective prevention for high-risk students (Preventure); (3) combined universal and selective prevention (Climate Schools and Preventure [CAP]); or (4) health education as usual (control). This study extends the follow-up period to 7-years post baseline. Primary outcomes were self-reported frequency of alcohol consumption and binge drinking, alcohol-related harms, and hazardous alcohol use, at the 7-year follow-up.

RESULTS

At 7-year follow-up, students in all 3 intervention groups reported reduced odds of alcohol-related harms compared to the control group (odds ratios [ORs] = 0.13-0.33), and the Climate (OR = 0.04) and Preventure (OR = 0.17) groups reported lower odds of hazardous alcohol use. The Preventure group also reported lower odds of weekly alcohol use compared to the control group (OR = 0.17), and the Climate group reported lower odds of binge drinking (OR = 0.12), holding mean baseline levels constant.

CONCLUSION

This study demonstrated that both universal and selective preventive interventions delivered in schools can have long-lasting effects and reduce risky drinking and related harms into adulthood. No added benefit was observed by delivering the combined interventions.

CLINICAL TRIAL REGISTRATION INFORMATION

The CAP Study: Evaluating a Comprehensive Universal and Targeted Intervention Designed to Prevent Substance Use and Related Harms in Australian Adolescents; https://www.anzctr.org.au/; ACTRN12612000026820.

It's the Content That Counts: Longitudinal Associations between Social Media Use, Parental Monitoring, and Alcohol Use in an Australian Sample of Adolescents Aged 13 to 16 Years

(1) Background: More time spent on social media has been linked to increased alcohol use, with exposure to peer alcohol-related content on social media (content exposure) named as a critical factor in this relationship. Little is currently known about whether early content exposure may have lasting effects across adolescent development, or about the capacity of parental monitoring of social media use to interrupt these links. (2) Methods: These gaps were addressed in both cross-sectional and longitudinal contexts among a longitudinal sample of Australian secondary school students (n = 432) across the ages of 13–16. (3) Results: Evidence was found for links between social media use and alcohol use frequency in early development. Social media time at age 13 was significantly associated with concurrent alcohol use frequency. At age 13, alcohol use frequency was significantly higher among those who reported content exposure compared to those who reported no exposure. Longitudinally, the frequency of alcohol use over time increased at a faster rate among participants who reported content exposure at age 13. In terms of parental monitoring, no longitudinal effects were observed. However, parental monitoring at age 13 did significantly reduce the concurrent relationship between alcohol use frequency and content exposure. (4) Conclusion: The impact of social media content exposure on alcohol use in adolescence may be more important than the time spent on social media, and any protective effect of parental monitoring on content exposure may be limited to the time it is being concurrently enacted.

Curriculum for neurogastroenterology and motility training: A report from the joint ANMS-ESNM task force

Although neurogastroenterology and motility (NGM) disorders are some of the most frequent disorders encountered by practicing gastroenterologists, a structured competency-based training curriculum developed by NGM experts is lacking. The American Neurogastroenterology and Motility Society (ANMS) and the European Society of Neurogastroenterology and Motility (ESNM) jointly evaluated the components of NGM training in North America and Europe. Eleven training domains were identified within NGM, consisting of functional gastrointestinal disorders, visceral hypersensitivity and pain pathways, motor disorders within anatomic areas (esophagus, stomach, small bowel and colon, anorectum), mucosal disorders (gastro-esophageal reflux disease, other mucosal disorders), consequences of systemic disease, consequences of therapy (surgery, endoscopic intervention, medications, other therapy), and transition of pediatric patients into adult practice. A 3-tiered training curriculum covering these domains is proposed here and endorsed by all NGM societies. Tier 1 NGM knowledge and training is expected of all gastroenterology trainees and practicing gastroenterologists. Tier 2 knowledge and training is appropriate for trainees who anticipate NGM disorder management and NGM function test interpretation being an important part of their careers, which may require competency assessment and credentialing of test interpretation skills. Tier 3 knowledge and training is undertaken by trainees interested in a dedicated NGM career and may be restricted to specific domains within the broad NGM field. The joint ANMS and ESNM task force anticipates that the NGM curriculum will streamline NGM training in North America and Europe and will lead to better identification of centers of excellence where Tier 2 and Tier 3 training can be accomplished.

Pathways to prevention: protocol for the CAP (Climate and Preventure) study to evaluate the long-term effectiveness of school-based universal, selective and combined alcohol misuse prevention into early adulthood

BACKGROUND

Alcohol use and associated harms are among the leading causes of burden of disease among young people, highlighting the need for effective prevention. The Climate and Preventure (CAP) study was the first trial of a combined universal and selective school-based approach to preventing alcohol misuse among adolescents. Initial results indicate that universal, selective and combined prevention were all effective in delaying the uptake of alcohol use and binge drinking for up to 3 years following the interventions. However, little is known about the sustainability of prevention effects across the transition to early adulthood, a period of increased exposure to alcohol and other drug use. This paper describes the protocol for the CAP long-term follow-up study which will determine the effectiveness of universal, selective and combined alcohol misuse prevention up to 7 years post intervention, and across the transition from adolescence into early adulthood.

METHODS

A cluster randomized controlled trial was conducted between 2012 and 2015 with 2190 students (mean age: 13.3 yrs) from 26 Australian high schools. Participants were randomized to receive one of four conditions; universal prevention for all students (Climate); selective prevention for high-risk students (Preventure); combined universal and selective prevention (Climate and Preventure; CAP); or health education as usual (Control). The positive effect of the interventions on alcohol use at 12-, 24- and 36-month post baseline have previously been reported. This study will follow up the CAP study cohort approximately 5- and 7-years post baseline. The primary outcome will be alcohol use and related harms. Secondary outcomes will be cannabis use, alcohol and other drug harms including violent behavior, and mental health symptomatology. Analyses will be conducted using multi-level, mixed effects models within an intention-to-treat framework.

DISCUSSION

This study will provide the first ever evaluation of the long-term effectiveness of combining universal and selective approaches to alcohol prevention and will examine the durability of intervention effects into the longer-term, over a 7-year period from adolescence to early adulthood.

TRIAL REGISTRATION

This trial was registered in the Australian New Zealand Clinical Trials Registry ( ACTRN12612000026820 ) on January 6th 2012.

Systematic review: role of acid, weakly acidic and weakly alkaline reflux in gastro-oesophageal reflux disease

BACKGROUND

The importance of weakly acidic and weakly alkaline reflux in gastro-oesophageal reflux disease (GERD) is gaining recognition.

AIM

To quantify the proportions of reflux episodes that are acidic (pH <4), weakly acidic (pH 4-7) and weakly alkaline (pH >7) in adult patients with GERD, and to evaluate their correlation with symptoms.

METHODS

Studies were identified by systematic PubMed and Embase searches. Data are presented as sample-size weighted means and 95% confidence intervals.

RESULTS

In patients with GERD taking a proton pump inhibitor (PPI), 80% (76-84%) of reflux episodes were weakly acidic or weakly alkaline and 83% (78-88%) of reflux symptom episodes were associated with weakly acidic or weakly alkaline reflux episodes. In patients with GERD not taking a PPI, 63% (59-67%) of reflux episodes were acidic and 72% (57-87%) of reflux symptom episodes were associated with acid reflux episodes. Six studies presented data separately for weakly alkaline reflux, which accounted for <5% of all reflux episodes, both on and off PPI therapy.

CONCLUSIONS

Weakly acidic reflux underlies the majority of reflux episodes in patients with GERD on PPI therapy, and is the main cause of reflux symptoms occurring despite PPI therapy.

The GABA(B) receptor agonist AZD9343 inhibits transient lower oesophageal sphincter relaxations and acid reflux in healthy volunteers: a phase I study

BACKGROUND

Transient lower oesophageal sphincter relaxations (TLESRs) represent an interesting target for the treatment of gastro-oesophageal reflux. Baclofen reduces TLESRs and reflux episodes, but is not optimal for clinical application because of its central side effects. Therefore, new agents are required.

AIM

To study the effect of AZD9343, a new selective GABA(B) receptor agonist, in healthy volunteers.

METHODS

A total of 27 subjects participated in a placebo-controlled, randomized, two-centre phase I study. Subjects underwent oesophageal manometry and pH-metry for 3 h postprandially. Before meal ingestion, a single oral dose of placebo, 60 and 320 mg AZD9343 or 40 mg baclofen was given on four separate days.

RESULTS

Somnolence was reported after 320 mg AZD9343 and baclofen. Reversible short-lasting paraesthesia was reported after AZD9343. AZD9343 320 mg and baclofen significantly reduced the number of TLESRs with 32% and 40% respectively. Acid reflux was significantly decreased by AZD9343 and baclofen. Like baclofen, AZD9343 increased LES pressure before meal intake. AZD9343 320 mg and baclofen significantly reduced the swallowing rate.

CONCLUSIONS

Like baclofen, AZD9343 dose-dependently decreases the number of TLESRs and acid reflux episodes, increases LES pressure and reduces swallowing, extending the concept that GABA(B) agonists are potent reflux inhibitors. However, discovery of analogues with an improved side effect profile is warranted.

Review article: acidity and volume of the refluxate in the genesis of gastro-oesophageal reflux disease symptoms

BACKGROUND

A number of mechanisms, other than acid reflux, may be responsible for the symptoms of gastro-oesophageal reflux disease.

AIM

To assess the importance of non-acid reflux mechanisms.

METHODS

This review is based on presentations and discussion at a workshop, where specialists in the field analysed data relating to these mechanisms.

RESULTS

Weakly acidic reflux, pH (4-7), detected with impedance-pHmetry is associated with regurgitation and atypical gastro-oesophageal reflux disease symptoms. It is not clear whether pepsin and trypsin can elicit symptoms, but bile can elicit heartburn. The magnitude of reflux-induced oesophageal distension can be determined by high frequency ultrasonography and is not reduced by proton pump inhibition, suggesting that persisting symptoms 'on' a proton pump inhibitor may still be due to oesophageal distension by non-acidic reflux. Exaggerated longitudinal muscle contraction can induce non-acid-related heartburn. Preliminary studies showed a positive effect of baclofen, surgery or endoscopic procedures to reduce weakly acidic reflux.

CONCLUSION

Mechanisms other than acid reflux are involved in some of the symptoms of gastro-oesophageal reflux disease. Controlled outcome studies are needed to clarify their roles and the indications for antireflux procedures in patients with persistent symptoms whilst 'on' a proton pump inhibitor.

Role of alimentation in irritable bowel syndrome

BACKGROUND

Different food items are made responsible for irritable bowel syndrome (IBS) symptoms, but the physiopathology of IBS remains unclear.

AIMS

During a meeting in Nice, France, experts of the European Working Team of the IBiS Club discussed selected data regarding the relationships between alimentation, food items (including fibers) and IBS symptoms.

METHODS/RESULTS

Food allergy remains a difficult diagnosis, but medical and general history, presence of general symptoms such as skin rash, and hypersensitivity tests may help in achieving a positive diagnosis. On the other hand, food intolerance is more confusing because of the subjectivity of the relationship between ingestion of certain foods and the appearance of clinical symptoms. Different food items which are commonly implicated in adverse reactions mimicking IBS were found to be stimulants for the gut, suggesting that patients with predominant diarrhea IBS have to be carefully questioned about consumption of different kinds of food (i.e., coffee, alcohol, chewing gum, soft drinks) and not only on lactose ingestion. Gas production is discussed on the basis of retention of intestinal gas as well as on malabsorption of fermentable substrates. The role of a large amount of this kind of substrate reaching the colon is suggested as a potential mechanism of IBS-type symptoms in overeating patients. Regarding the role of fiber in IBS, the expert group concluded that fibers are not inert substances and that they could trigger pain or bloating in some IBS patients.

CONCLUSION

Despite numerous reviews on this subject, it is very difficult to give general dietary advice to IBS patients, but dieteticians may have a positive role in managing such patients.

The rectum: a window to irritable bowel syndrome?

This report summarizes current concepts and information gathered to date about the rectum in the irritable bowel syndrome (IBS) that were presented at the 10th meeting of IBiS Club held in Leuven, Belgium. A working group of experts in the field of IBS discussed whether the rectum or the whole colon is the better site to test in IBS patients and provided suggestions for a number of areas where further advances are required.

Nongastrointestinal disorders in the irritable bowel syndrome

A large proportion of irritable bowel syndrome (IBS) patients also complain of other functional disorders, such as headache, noncardiac chest pain, low back pain, and dysuria. Some of these features, particularly headache, may have a negative influence on the outcome of IBS. In a large proportion of female IBS patients, sexual intercourse triggers the symptoms, and frequently IBS symptoms exacerbate during menses. These gynecological-type symptoms often mislead the patients to the gynecological clinic, which may imply unnecessary investigations and inappropriate treatments. The diagnostic criteria of the fibromyalgia syndrome include IBS, and hence, the apparent relationship of both syndromes is difficult to analyze. On the other hand, no convincing evidence has been produced to date to sustain an association between IBS and the chronic fatigue syndrome.

Relationship between surface electrogastrography and antropyloric pressures

The cutaneous electrogastrogram (EGG) and intraluminal antropyloroduodenal pressures were recorded in 12 healthy volunteers for 30-min periods during phase II of the interdigestive motor complex, during intraduodenal infusion of 10% triglyceride, and after intravenous erythromycin (3 mg/kg). During phase II, the frequency of the EGG was relatively constant in each individual, with a median frequency of 0.046 Hz [2.8 counts per minute (cpm)]. EGG frequency was greater (P < 0.05) than the median rate of antral pressure waves (1.8 cpm). The suppression of antral pressure waves (P < 0.05) and stimulation of isolated pyloric pressure waves (IPPWs) (P < 0.05) produced by triglyceride infusion were not associated with changes in EGG frequency compared with phase II. The frequency of the EGG and the rate of IPPWs were comparable. After erythromycin, EGG frequency was 0.03 Hz (1.8 cpm), less than during both phase II and triglyceride infusion (P < 0.05) and almost identical to the rate of antral pressure waves. Pressure waves were nearly always associated with an EGG signal. In contrast, the temporal relationship between the EGG signal and pressure waves was variable. During triglyceride infusion (r = 0.83, P < 0.001) and after erythromycin (r = 0.83, P < 0.001) there was a close (approximately 1:1) relationship between the rate of pressure waves and EGG frequency. However, there was no significant relationship (r = 0.32, not significant) between the number of pressure waves and EGG frequency frequency during pase II.(ABSTRACT TRUNCATED AT 250 WORDS)

Stereospecific effects of intraduodenal tryptophan on pyloric and duodenal motility in humans

BACKGROUND

L-Tryptophan delays gastric emptying in animals to a greater extent than D-tryptophan, but none of the possible motor mechanisms responsible for this stereospecific effect have been evaluated.

METHODS

In 11 healthy volunteers antropyloroduodenal pressures were recorded in the fasted state with a sleeve/sidehole manometric assembly during 20-min intraduodenal infusions (2 ml.min-1) of isotonic L- and D-tryptophan (50 mM, pH 5.7) and normal saline (pH 5.5), given in randomized order.

RESULTS

Intraduodenal L-tryptophan increased basal pyloric pressure (p < 0.05), whereas D-tryptophan had no effect. In contrast, L- and D-tryptophan both stimulated (p < 0.05) localized phasic pyloric pressure waves, and there was no significant difference in the responses. The number of duodenal pressure waves was greater during infusion of L-tryptophan than during D-tryptophan (p < 0.05).

CONCLUSION

We conclude that intraduodenal tryptophan has stereospecific effects on pyloric and duodenal motility. Although the precise contribution of these differential effects to gastric emptying remains to be clarified, they may be partially responsible for the differences in gastric emptying of D-tryptophan and L-tryptophan.

Effects of duodenal distention on fasting and postprandial antropyloroduodenal motility in humans

BACKGROUND/AIMS

Mechanoreceptors in the proximal small intestine may play an important role in the regulation of gastric emptying. Balloon distention of the duodenum causes fundic relaxation. The purpose of the present study was to determine the effect of stimulation of duodenal mechanoreceptors on both fasting and postprandial antropyloroduodenal motility in humans.

METHODS

Antropyloroduodenal pressures were recorded in 12 healthy volunteers with a sleeve-sidehole assembly, incorporating two balloons 5 and 20 cm distal to the pylorus. Duplicate proximal and distal duodenal balloon distensions with 10, 20, and 30 mL of air for 2.5 minutes were performed separately and in randomized order both during fasting and after a meal.

RESULTS

During fasting, proximal and distal distention at all volumes increased the number of isolated pyloric pressure waves (P < 0.05) and basal pyloric pressure (P < 0.05), and the response to proximal distention was greater (P < 0.05). Postprandially, proximal and distal distention increased basal pyloric pressure (P < 0.05) with a greater response to proximal distention (P < 0.05), but had no effect on isolated pyloric pressure waves. Both during fasting and postprandially, there were more synchronous and less antegrade antral waves during distention (P < 0.05). The number of duodenal pressure waves increased during proximal (P < 0.05) but not distal distention.

CONCLUSIONS

Stimulation of duodenal mechanoreceptors by balloon distention has significant and region-dependent effects on antropyloroduodenal motility that vary between fasting and postprandial states.