Functional Dyspepsia: A Narrative Review With a Focus on Sex-Gender Differences

The prevalence of functional dyspepsia using Rome IV questionnaire among chronic kidney disease patients

Background: Symptoms of dyspepsia are usually encountered by chronic kidney disease patients. Abdominal discomfort is commonly seen in CKD patients with no other causes of organic affection. Aim: to determine the prevalence of functional dyspepsia in CKD patients, and which subtype is predominant in them. Materials and patients: This observational study included 150 CKD patients. Clinical and laboratory data were recorded for every patient. All the patients were interviewed using the ROME IV questionnaire of functional dyspepsia. Patients fulfilling criteria for functional dyspepsia were exposed to upper GI endoscopy. Results: Overall, 73 (48.7%) of CKD patients were males and 77 (51.3%) were females with mean age of (45.71 ± 9.59) and mean BMI (26.58 ± 5.39). The frequency of functional dyspepsia among CKD patients was determined to be 14.7% (22 out of 150 patients). Among those affected by functional dyspepsia, the most prevalent subtype was found to be Epigastric Pain Syndrome (EPS), accounting for 59% (13 out of 22 cases). The most common predictor of FD in CKD patients was chronic HCV infection, hemodialysis, stage of CKD and eGFR as revealed by Univariate regression analysis. Conclusion: The prevalence of FD amongst CKD patients is 14.7% with EPS the predominant subtype. Male patients, HCV patients, patients with higher CKD stages and highly impaired eGFR (low eGFR) are more probable to have FD.

Global prevalence of functional dyspepsia according to Rome criteria, 1990-2020: a systematic review and meta-analysis

Although functional dyspepsia (FD) is a common functional gastroduodenal disorder with a high socioeconomic burden, little is known about its global prevalence. Thus, we performed a comprehensive study to estimate long-term trends in the prevalence of FD. We searched PubMed/MEDLINE, Embase, and Google Scholar from 1990 to 2022 for population-based studies that reported the prevalence of FD in adults (≥ 18 years old) according to Rome I, II, III, or IV criteria. The prevalence of FD was extracted from included studies to obtain pooled prevalence with 95% confidence intervals (CI) and 95% prediction intervals. Subgroup analysis was performed according to certain characteristics, including geographic region. A total of 44 studies met the eligibility criteria, including 256,915 participants from 40 countries across six continents. The overall global pooled prevalence of FD was 8.4% (95% CI 7.4-.9.5). The prevalence was the highest in Rome I (11.9%; 95% CI 5.1-25.4) and lowest in Rome IV (6.8%; 95% CI 5.8-7.9). Developing countries showed a higher prevalence than developed countries (9.1% versus 8.0%), and prevalence was higher in women, irrespective of the definition used (9.0% versus 7.0%). The pooled prevalence gradually decreased from 1990 to 2020 (12.4% [8.2-18.3] in 1990-2002 versus 7.3% [6.1-8.7] in 2013-2020). The prevalence of FD differs by country, economic status, geographical region, and sex, and the global prevalence has been gradually declining. Despite the heterogeneity of sample population, our study estimates the current global burden of FD and provides information to heath care policy decisions.

Intrapyloric Botulinum Toxin Injection for Refractory Nausea and Vomiting in Pediatric Patients

OBJECTIVES

Chronic nausea and vomiting may be associated with gastroparesis or other conditions. Poor mechanistic understanding of symptoms often precludes targeted therapy. Numerous case series suggest that intrapyloric botulinum toxin injection (IPBI) may be beneficial in treating gastroparesis and dyspepsia in children. We hypothesized that nausea, vomiting, and other symptoms, independent of gastroparesis, may improve with IPBI. We sought to identify gastric emptying (GE) and manometric patterns in IPBI responders versus nonresponders.

METHODS

Electronic records of 25 pediatric patients who received IPBI for refractory nausea, vomiting, or both were retrospectively reviewed. We assessed symptom improvement post-IPBI and compared symptoms, GE, and antroduodenal manometry (ADM) findings between IPBI responders and nonresponders.

RESULTS

At least one major symptom improved in 19 patients (76%) after IPBI. Of 22 patients completing a GE study, 14 had delayed GE with no significant difference between IPBI responders and nonresponders. Of 22 patients who underwent ADM, 18 had normal fasting peristalsis, 5 had postprandial antral hypomotility, 4 had neuropathic findings, and 19 had pylorospasm. IPBI responders, compared to nonresponders, demonstrated higher antral pressures with feeding ( P < 0.0001) and shorter duration of pylorospasm ( P = 0.0036). Antral pressures did not differ significantly with fasting or following motilin agonists.

CONCLUSIONS

Our findings suggest that IPBI may have therapeutic benefit in pediatric patients with chronic nausea and/or vomiting, independent of gastroparesis. ADM findings of intact antral peristalsis and elevated antral pressures, in conjunction with efficacy of IPBI, support pyloric non-relaxation as a potential contributor to nausea and/or vomiting in pediatric patients.

Gender-based research underscores sex differences in biological processes, clinical disorders and pharmacological interventions

Earlier research has presumed that the male and female biology is similar in most organs except the reproductive system, leading to major misconceptions in research interpretations and clinical implications, with serious disorders being overlooked or misdiagnosed. Careful research has now identified sex differences in the cardiovascular, renal, endocrine, gastrointestinal, immune, nervous, and musculoskeletal systems. Also, several cardiovascular, immunological, and neurological disorders have shown differences in prevalence and severity between males and females. Genetic variations in the sex chromosomes have been implicated in several disorders at young age and before puberty. The levels of the gonadal hormones estrogen, progesterone and testosterone and their receptors play a role in the sex differences between adult males and premenopausal women. Hormonal deficiencies and cell senescence have been implicated in differences between postmenopausal and premenopausal women. Specifically, cardiovascular disorders are more common in adult men vs premenopausal women, but the trend is reversed with age with the incidence being greater in postmenopausal women than age-matched men. Gender-specific disorders in females such as polycystic ovary syndrome, hypertension-in-pregnancy and gestational diabetes have attained further research recognition. Other gender-related research areas include menopausal hormone therapy, the "Estrogen Paradox" in pulmonary arterial hypertension being more predominant but less severe in young females, and how testosterone may cause deleterious effects in the kidney while having vasodilator effects in the coronary circulation. This has prompted the National Institutes of Health (NIH) initiative to consider sex as a biological variable in research. The NIH and other funding agencies have provided resources to establish state-of-the-art centers for women health and sex differences in biology and disease in several academic institutions. Scientific societies and journals have taken similar steps to organize specialized conferences and publish special issues on gender-based research. These combined efforts should promote research to enhance our understanding of the sex differences in biological systems beyond just the reproductive system, and provide better guidance and pharmacological tools for the management of various clinical disorders in a gender-specific manner.

Quality of life in Indian patients with functional dyspepsia: Translation and validation of the Hindi version of Short-Form Nepean Dyspepsia Index

BACKGROUND/PURPOSE

Patients with functional dyspepsia (FD) have poor health-related quality of life (HRQOL), but Indian data are  lacking. Also, there is non-availability of validated disease-specific questionnaire to assess HRQOL in Hindi-speaking patients with dyspepsia. We aimed to develop and validate a reliable translation of Short-Form Nepean Dyspepsia Index (SF-NDI) in Hindi, and assess the impact of FD on HRQOL in Indian patients.

METHODS

Cross-cultural adaptation of English version of SF-NDI, translation to Hindi, and adaptation of Hindi version were performed using standard procedures. English and Hindi versions were assessed against Short Form-36 (SF-36), examining for internal consistency, test-retest reliability, and validity.

RESULTS

Total 211 FD patients (144 Hindi speaking, 67 English speaking) were enrolled (mean age 40.8 ± 11.7 years; male:female = 115:96). Median total SF-NDI scores for both languages were 38.75 and 40.0, respectively. Test-retest reliability intraclass correlation coefficients were 0.85 (Hindi) and 0.89 (English). Internal consistency evaluation revealed Cronbach's α coefficient of 0.79-0.86 (Hindi) and 0.78-0.89 (English). SF-NDI sub-scales showed moderate to good correlation with various domains of SF-36 (content validity). There was significant (p &lt; 0.001) decline of HRQOL in patients with severe dyspepsia relative to those with mild dyspepsia (construct validity). On multivariate analysis, factors independently associated with HRQOL were duration of symptoms and dyspepsia severity.

CONCLUSION

Both English and Hindi versions of SF-NDI are reliable and valid for HRQOL assessment in Indian FD patients, and will be useful in future epidemiological and clinical studies. Indian FD patients have poor HRQOL, being worse in those with severe dyspepsia and longer duration of symptoms.

Efficacy of Slow Nutrient Drinking Test for Evaluating Postprandial Distress Symptom in Japanese Patients With Functional Dyspepsia

Background/Aims

Methods

Results

The [13 C]octanoic acid breath test for gastric emptying quantification: A focus on nutrition and modeling

Gastric emptying (GE) is the process of food being processed by the stomach and delivered to the small intestine where nutrients such as lipids are absorbed into the blood circulation. The combination of an easy and inexpensive method to measure GE such as the CO₂ breath test using the stable isotope [¹³C]octanoic acid with semi‐mechanistic modeling could foster a wider application in nutritional studies to further understand the metabolic response to food. Here, we discuss the use of the [¹³C]octanoic acid breath test to label the solid phase of a meal, and the factors that influence GE to support mechanistic studies. Furthermore, we give an overview of existing mathematical models for the interpretation of the breath test data and how much nutritional studies could benefit from a physiological based pharmacokinetic model approach.

Yokukansan Suppresses Gastric Hypersensitivity and Eosinophil-associated Microinflammation in Rats With Functional Dyspepsia

Background/Aims

Herbal medicine is an important complementary therapy for functional dyspepsia (FD). However, its effect against gastric hypersensitivity in patients with FD has rarely been evaluated. Yokukansan (YKS), a traditional Japanese herbal medicine, is effective against neuropathic and inflammatory pain. This study aims to use a maternal separation (MS) stress-induced FD model to investigate the effects of YKS against gastric hypersensitivity, gastric motility, and duodenal micro-inflammation.

Methods

The MS stress model was established by separating newborn Sprague-Dawley rats from their mothers for 2 hours a day from postnatal days 1 to 10. At the age of 7-8 weeks, the rats were treated with YKS at a dose of 5 mL/kg (1 g/kg) for 7 consecutive days. After YKS treatment, electromyographic activity in the acromiotrapezius muscle by gastric distention and the gastric-emptying rate were assessed. Immunohistochemical analysis of eosinophils in the duodenum and phosphorylated extracellular signal-regulated kinase (p-ERK) 1/2 in the spinal cord was performed.

Results

YKS treatment suppressed MS stress-induced gastric hypersensitivity and decreased the elevated levels of p-ERK1/2 in the spinal cord. In the gastroduodenal tract, YKS inhibited eosinophil-associated micro-inflammation but did not improve gastric dysmotility.

Conclusions

YKS treatment improved gastric hypersensitivity by alleviating eosinophil-associated micro-inflammation in the gastroduodenal tract. This treatment may be considered an effective therapeutic option for epigastric pain and micro-inflammation in patients with FD.

Association Between Body Mass Index and Functional Dyspepsia in Young Japanese People

Background/Aims

Evidence regarding the association between body mass index (BMI) and functional dyspepsia (FD) in the Asian population is limited. Further, no study has evaluated this issue in young people in Asian and Western populations. Thus, we aim to investigate this issue among young Japanese people.

Methods

The study subjects comprised of 8923 Japanese university students. BMI was divided into 4 categories (quartiles) on the basis of the study subjects’ distribution (lowest, low, moderate, and high [reference]). The definition of lean, normal, overweight, and obese was BMI < 18.5 kg/m², 18.5 ≤ BMI < 25 kg/m² (reference), 25 kg/m² ≤ BMI < 30 kg/m², and 30 kg/m² ≤ BMI, respectively. The definition of FD was based on the Rome III criteria.

Results

The prevalence of FD was 1.9% in this cohort. The lowest BMI was independently associated with FD after adjustment (adjusted odds ratio [OR], 2.88; 95% confidence interval [CI], 1.46-3.67); P for trend = 0.001). The lowest BMI was independently associated with FD in women but not in men (OR, 2.94; 95% CI, 1.59-5.77; P for trend = 0.001). Leanness was independently associated with FD in total and in women but not in men (total adjusted OR, 2.01; 95% CI, 1.40-2.86) and women (OR, 2.19; 95% CI, 1.35-3.45). However, interaction analysis showed no significant difference for sex.

Conclusions

Among young Japanese people, BMI may be independently inversely associated with FD. Leanness may be an independent associated factor for FD in the young Japanese women.

A novel duodenal-release formulation of caraway oil and L-menthol is a safe, effective and well tolerated therapy for functional dyspepsia

BACKGROUND

A randomized, placebo-controlled clinical trial (FDREST) of a novel formulation of caraway oil and L-menthol (COLM-SST) demonstrated symptom relief in patients with functional dyspepsia (FD). Two follow-up studies were conducted to evaluate patient satisfaction, self-regulated dosing, and long-term safety data: FDACT, Functional Dyspepsia Adherence and Compliance Trial, and FDSU36, Functional Dyspepsia Safety Update at 36 months.

METHODS

A patient reported outcomes (PRO) questionnaire was designed and distributed online to assess real-world satisfaction and dosing frequency of open-label COLM-SST in patients with FD. A separate study analyzing voluntary safety surveillance data evaluated the frequency and severity of reported adverse events (AEs).

RESULTS

A total of 600 FD patients were enrolled in the PRO study. Ninety five percent of respondents reported a major or moderate improvement in their FD symptoms and 91.7% indicated a major or moderate improvement in quality of life (QOL) using COLM-SST. Between 1 and 4 capsules were consumed daily by 91.2% of respondents, with 56.2% taking them before meals. Symptom relief was rapid, with 86.4% of respondents indicating relief within 2 h of taking COLM-SST. Few adverse events (AEs) were reported (0.0187%) by patients using COLM-SST. No serious AEs were identified.

CONCLUSION

COLM-SST is safe, well tolerated, and provides rapid relief of FD symptoms. These findings, demonstrated in the FDREST trial, were further supported by a large prospective PRO study evaluating self-regulated dosing frequency, symptom improvement, and QOL. COLM-SST was well-tolerated based on review of AE data at 36 months.

Subcortical-Cortical Functional Connectivity as a Potential Biomarker for Identifying Patients with Functional Dyspepsia

The diagnosis of functional dyspepsia (FD) presently relies on the self-reported symptoms. This study aimed to determine the potential of functional brain network features as biomarkers for the identification of FD patients. Firstly, the functional brain Magnetic Resonance Imaging data were collected from 100 FD patients and 100 healthy subjects, and the functional brain network features were extracted by the independent component analysis. Then, a support vector machine classifier was established based on these functional brain network features to discriminate FD patients from healthy subjects. Features that contributed substantially to the classification were finally identified as the classifying features. The results demonstrated that the classifier performed pretty well in discriminating FD patients. Namely, the accuracy of classification was 0.84 ± 0.03 in cross-validation set and 0.80 ± 0.07 in independent test set, respectively. A total of 15 connections between the subcortical nucleus (the thalamus and caudate) and sensorimotor cortex, parahippocampus, orbitofrontal cortex were finally determined as the classifying features. Furthermore, the results of cross-brain atlas validation showed that these classifying features were quite robust in the identification of FD patients. In summary, the current findings suggested the potential of using machine learning method and functional brain network biomarkers to identify FD patients.

A comprehensive review of functional dyspepsia in pediatrics

Functional gastrointestinal disorders have been known as a diagnosis of exclusion since the Rome Foundation first created these criteria in 1990. Since that time, a large amount of research and clinical data has better clarified the mechanisms and treatment options for these. Functional dyspepsia is caused by physiologic, genetic, environmental, and psychological factors, as well as various functional abnormalities, such as increased sensitivity to acid, increased sensitivity to duodenal lipids and low-grade inflammation. This disorder has significant symptom overlap between other functional disorders, such as irritable bowel syndrome and gastroparesis, but has differential criteria and two new subclasses: postprandial distress syndrome and epigastric pain syndrome. Diagnosis of functional dyspepsia should be based upon appropriate clinical evaluation in tandem with Rome IV criteria. In recent years, many treatment measures for functional dyspepsia have been studied, such as pharmacologic intervention, behavioral therapy, or alternative therapy, an example being hypnotherapy. These treatment measures have proven to be effective in symptom reduction in pediatrics. Though this disorder is functional, it has been shown to cause a significant impact on pediatric patients' quality of life continuing into adulthood.

Systematic Survey of the Alteration of the Faecal Microbiota in Rats With Gastrointestinal Disorder and Modulation by Multicomponent Drugs

Gastrointestinal disorder (GID) is a global health disease which leads to heavy public medical burden. Disorders in the intestinal flora have been found in gastrointestinal disorder patients. However, the interaction between GID and the intestinal flora in faecal has not been studied comprehensively. In addition, multicomponent drugs represented by traditional Chinese medicine (TCM) are widely used for treating GID, but their modulation of the intestinal flora has not been investigated. Therefore, in this study, a high-throughput sequencing strategy was used to investigate alterations in the intestinal flora in a rat GID model, followed by an investigation of the modulation by a representative TCM, Xiaoerfupi (XEFP) granule. The results showed that in rats with GID, the relative abundances of Erysipelotrichaceae, Lachnospiraceae, Streptococcaceae increased and that of Ruminococcaceae decreased. At the macro level, the levels of LysoPC(16:0), LysoPC(20:2), LysoPC(15:0), LysoPC(20:2 (11Z, 14Z)), LysoPC(20:1), LysoPC(15:0), LysoPC(20:0) and LysoPE (0:0/20:0) in serum increased and levels of PC(36:4), PC(38:4), PC(o-36;4), PE (MonoMe(13,5)/MonoMe(11,5)) decreased. The imbalance of metabolites was restored by XEFP through ether lipid metabolism pathway. Increase in the phyla Firmicutes/Bacteroidetes (F/B) ratio of the GID rats was restored by XEFP as well. Moreover, XEFP can relief the symptoms of GID rats by increasing bacteria Ruminococcaceae and decreasing Streptococcaceae, Erysipelotrichaceae and Lachnospiraceae in faecal microbiota level. This study represents a comprehensive survey of the interaction between GID and the intestinal flora and a systematic evaluation of modulation by a multicomponent drug.

Characterization of the A-type potassium current in murine gastric fundus smooth muscles

Transient outward, or "A-type," currents are rapidly inactivating voltage-gated potassium currents that operate at negative membrane potentials. A-type currents have not been reported in the gastric fundus, a tonic smooth muscle. We used whole cell voltage clamp to identify and characterize A-type currents in smooth muscle cells (SMCs) isolated from murine fundus. A-type currents were robust in these cells with peak amplitudes averaging 1.5 nA at 0 mV. Inactivation was rapid with a time constant of 71 ms at 0 mV; recovery from inactivation at -80 mV was similarly rapid with a time constant of 75 ms. A-type currents in fundus were blocked by 4-aminopyridine (4-AP), flecainide, and phrixotoxin-1 (PaTX1). Remaining currents after 4-AP and PaTX1 displayed half-activation potentials that were shifted to more positive potentials and showed incomplete inactivation. Currents after tetraethylammonium (TEA) displayed half inactivation at -48.1 ± 1.0 mV. Conventional microelectrode and contractile experiments on intact fundus muscles showed that 4-AP depolarized membrane potential and increased tone under conditions in which enteric neurotransmission was blocked. These data suggest that A-type K+ channels in fundus SMCs are likely active at physiological membrane potentials, and sustained activation of A-type channels contributes to the negative membrane potentials of this tonic smooth muscle. Quantitative analysis of Kv4 expression showed that Kcnd3 was dominantly expressed in fundus SMCs. These data were confirmed by immunohistochemistry, which revealed Kv4.3-like immunoreactivity within the tunica muscularis. These observations indicate that Kv4 channels likely form the A-type current in murine fundus SMCs.

Correlation between the symptoms of upper gastrointestinal disease and endoscopy findings: Implications for clinical practice

Objective

Digestive symptoms are the most common complaints among patients who seek primary healthcare services. This study aims to identify digestive symptoms and determine their association with upper gastrointestinal endoscopy findings in patients treated at a public endoscopy centre in Northeast Brazil.

Methods

We conducted a cross-sectional study using data from 751 patients with digestive symptoms who had an indication for upper gastrointestinal endoscopy. We identified the association between these variables through Fisher's exact test or Chi-square test and calculated the odds ratio.

Results

Epigastric pain occurred in 83%, post-prandial plenitude in 72.6%, and heartburn in 72.3% of the patients. Women were more likely to present with epigastric pain (p = 0.001; odds ratio [OR] = 1.25; confidence interval [CI] = 1.07-1.47), post-prandial plenitude (p = 0.001; OR = 1.21; CI = 1.06-1.37), retrosternal pain or burning (p = 0.03; OR = 1.11; CI = 1.004-1.24), heartburn (p = 0.04; OR = 1.10; CI = 0.98-1.24), unintentional weight loss (p = 0.01; OR = 1.12; CI = 1.02-1.24), and dysphagia (p = 0.01; OR = 1.14; CI = 1.03-1.25). There was no statistically significant association between digestive symptoms and endoscopic findings of the upper gastrointestinal tract. Additionally, there was no significant association between digestive symptoms and abnormalities detected by endoscopy.

Conclusion

Dyspeptic symptoms of epigastric pain, post-prandial fullness, and heartburn were the most common symptoms in patients referred for endoscopy. Dyspepsia, heartburn, and dysphagia were more common in women than in men. Digestive symptoms were not associated with positive endoscopy findings or abnormalities detected by endoscopy.

Impact of improvement of sleep disturbance on symptoms and quality of life in patients with functional dyspepsia

BACKGROUND/AIMS

Functional dyspepsia (FD) is often comorbid with sleep disturbance. However, it is not fully understood how sleep disturbance affects the pathophysiology of FD. We aimed to investigate the relationship between FD and sleep disturbance.

METHODS

We prospectively enrolled 20 FD patients with sleep disturbance between December 2018 and July 2019. Patients took sleep aids for 4 weeks and filled out questionnaires before and after taking sleep aids. Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and Athens Insomnia Scale (AIS) were used to evaluate the severity of their sleep disturbance. Modified Frequency Scale for the Symptoms of Gastroesophageal Reflux Disease (mFSSG), Gastrointestinal Symptom Rating Scale (GSRS), and the Japanese version of Patient Assessment of Constipation Quality of Life (JPAC-QOL) were used to evaluate the severity of GI symptoms. Short-Form 36-Item Health Survey (SF-36) was used to evaluate QOL. Pre- and post-sleep medication values of questionnaires were compared.

RESULTS

Among 20 enrolled patients, 16 completed the study protocol. Zolpidem, eszopiclone, and suvorexant were administered to six, nine, and one patient, respectively. Each median total score of questionnaires (pre-/post-sleep medication, respectively) was as follows: PSQI, 10.0/8.5; ESS, 12.5/5.0; AIS, 10.0/4.0; mFSSG, 21.0/16.0; GSRS, 44.0/31.0 (Pain in GSRS, 11.0/5.0); JPAC-QOL, 26.0/15.5; SF-36, 63.9/71.9. All of these results showed statistically significant differences between pre- and post-sleep medication (p < 0.05).

CONCLUSIONS

Improvement of sleep disturbance by administration of sleep aids resulted in improvement of GI symptoms and QOL in patients with FD. This effect may be related to pain modification.

99mTc-sodium phytate is a valid alternative to the gold-standard 99mTc-sulfur colloid in the measurement of gastric emptying among healthy multi-ethnic Asian population: results of a randomized cross-over trial

BACKGROUND

It is unclear if the 99mTc-sodium phytate (99mTc-SP) is as reliable as the gold-standard 99mTc-sulfur colloid (99mTc-SC) for gastric emptying scintigraphy (GES). This study is aimed to compare the emptying rates of both radiotracers in a prospective, randomized cross-over trial and to determine the normative data of a healthy multi-ethnic Asian population.

METHODS

Out of the 44 healthy individuals screened, 31 (14 females; mean age: 28.4 ± 7.0 years) were enrolled and underwent GES using the standardized egg-white meal. All participants were randomly assigned to either 99mTc-SP or 99mTc-SC on the first GES session before crossed over to the other formulation after 2 weeks.

RESULTS

Both kits achieved the radiochemical purities of > 95%. The median rate (95th upper normative limit) of gastric emptying, reported as total gastric meal retention between 99mTc-SP and 99mTc-SC, was found to be comparable at all measured time points: 0.5 h [85.0% (96.6%) vs. 82.0% (94.0%)], 1 h [70.0% (86.4%) vs. 65.0% (86.6%)], 2 h [31.0% (55.8%) vs. 25.0% (64.4%)], 3 h [7.0% (26.3%) vs. 5.0% (29.9%)], and 4 h [3.0% (10.3%) vs. 2.0% (9.9%)]; P > 0.05. In addition, both radiotracers correlated well (Kendall's Tau (τ) coefficient = 0.498, P < 0.001) and presented with a good agreement at the 4th-hour time frame based on the Bland-Altman plot analysis.

CONCLUSIONS

99mTc-SP is a valid radiotracer alternative to 99mTc-SC for routine GES examination. The normative values for both radiotracers have also been determined for the healthy multi-ethnic Asian population.

TRIAL REGISTRATION

This trial was registered retrospectively in the Thai Clinical Trials Registry on May 23rd, 2020 (Identifier: TCTR20200526004; http://www.clinicaltrials.in.th/index.php?tp=regtrials&menu=trialsearch&smenu=fulltext&task=search&task2=view1&id=6296 ).