Functional abdominal pain disorders and asthma: two disorders, but similar pathophysiology?

Prevalence of functional abdominal pain disorders and functional constipation in adolescents

AIM

Functional abdominal pain disorders (FAPDs) and functional constipation (FC) are the common functional gastrointestinal disorders in adolescents. We aimed to determine the prevalence of FAPDs and FC in adolescents using the Rome IV Questionnaire of Pediatric Gastrointestinal Symptoms and the factors associated with these two functional gastrointestinal disorders.

METHODS

A survey for the prevalence of FAPDs and FC in adolescents was carried out at two high schools. A translated and validated Thai version of Rome IV Questionnaire of Pediatric Gastrointestinal Symptoms was used. Potential associated factors were also collected. Psychosocial problems were evaluated by using the Strengths and Difficulties Questionnaire.

RESULTS

A total of 1700 adolescents (55.5% females) with a mean age (SD) of 16.1 (0.9) years were enrolled. The prevalence of FAPDs and FC was 5.3% and 8.1%, respectively. The subtypes of FAPDs were functional dyspepsia (4.7%; postprandial distress syndrome 3.9% and epigastric pain syndrome 0.8%), irritable bowel syndrome (0.6%), abdominal migraine (0.4%) and functional abdominal pain not otherwise specified (0.3%). Multiple logistic regression analysis revealed that FAPDs were associated with female gender (odds ratio (OR) 3.3, 95% confidence interval (CI): 1.7-6.4), underlying allergic diseases (OR 3.2, 95% CI: 1.6-6.6) and concomitant emotional problem (OR 2.7, 95% CI: 1.2-5.9). No significant associated factors with FC were found.

CONCLUSION

FAPDs and FC are common in adolescents. Postprandial distress syndrome is the most common subtype of FAPD. Associated factors for FAPDs may suggest hormonal, immune-related and psychological involvement in the disease pathogenesis.

Gastric motility and pulmonary function in children with functional abdominal pain disorders and asthma: A pathophysiological study

BACKGROUND

An association has been shown between functional abdominal pain disorders (FAPDs) and asthma. However, the exact reason for this association is obscured. The main objective of this study is to identify the possible underlying pathophysiological mechanisms for the association between FAPDs and asthma using gastric motility and lung function tests.

METHODS

This was a cross-sectional comparative study that consisted of four study groups. Twenty-four children (age 7-12 years) each were recruited for four study groups; asthma only, FAPDs only, both asthma and FAPDs, and healthy controls. Asthma was diagnosed using the history and bronchodilator reversibility test. The diagnosis of FAPDs was made using Rome IV criteria. All subjects underwent ultrasound assessment of gastric motility and pulmonary function assessment by spirometry, using validated techniques.

RESULTS

All gastric motility parameters, gastric emptying rate, amplitude of antral contraction, and antral motility index, were significantly impaired in children with FAPDs only, children with asthma only, and children with both asthma & FAPDs, compared to controls (p<0.05). Pulmonary function parameters indicating airway obstruction (FEV1/FVC ratio, peak expiratory flow rate, FEF25-75%) were not impaired in children with FAPDs only compared to controls (p>0.05), but significantly impaired in children with asthma and children with both disorders. Antral motility index correlated with the FEV1/FVC ratio (r = 0.60, p = 0.002) and FEF25%-75% (r = 0.49, p = 0.01) in children with both asthma and FAPDs.

CONCLUSIONS

Gastric motor functions were significantly impaired in children with asthma, children with FAPDs, and children with both disorders. Motility index, measuring overall gastric motor activity, showed a significant positive correlation with lung function parameters that measure airflow limitation. Therefore, these diseases might arise as a result of primary disturbance of smooth muscle activity in the airways and gastrointestinal wall, which could be a possible pathophysiological mechanism for this association between asthma and FAPDs.