Most patients referred to tertiary care with suspected gastroparesis (GP) actually have a different condition, usually functional dyspepsia (FD), a new retrospective review suggests.
The researchers analyzed the records of 339 patients referred for tertiary evaluation of GP at one center. Overall, 19.5% of patients were confirmed to have GP, whereas 80.5% were given an alternative diagnosis, with FD being the most common (44.5%).
Contributing to initial misdiagnosis are the similarity in presentation between patients with GP and FD and low rates of gastric emptying evaluation using the recommended test protocol, lead author David J. Cangemi, MD, Division of Gastroenterology, Mayo Clinic, Jacksonville, Florida, and colleagues write.
The findings “reaffirm guidelines noting that gastroparesis cannot be diagnosed based on symptoms alone,” they write.
Because FD is more prevalent than GP, FD “should be considered first in patients with characteristic upper GI [gastrointestinal] symptoms,” they add.
The review was published online February 3 in Clinical Gastroenterology and Hepatology.
Similarities Breed Confusion
GP and FD are the two most common sensorimotor disorders of the stomach, and both are characterized by abdominal pain, nausea, early satiety, and vomiting, the researchers write.
While GP is defined by delayed gastric emptying, it is also seen in 20%-30% of patients with FD. This overlap and symptom commonality make “the diagnosis difficult for many healthcare providers,” they write.
The researchers hypothesized that GP is frequently incorrectly overdiagnosed in the community and that FD, along with other disorders that mimic GP, are underdiagnosed.
Their retrospective review involved adult patients referred to their institution for the evaluation of GP between January 2019 and July 2021.
The team gathered information on patient demographics, medical comorbidities, diagnostic tests, and laboratory results. Researchers determined a final diagnosis after reviewing clinical notes, communications, and the results of tests conducted by experts.
Of the 339 patients, 82.1% were female and 85.6% White.
Diabetes was diagnosed in 21.7% of patients, of whom 59.7% had type 2 disease. Most patients (71.7%) had previously been diagnosed with gastroesophageal reflux disease, and 5.6% had been diagnosed with Helicobacter pylori. Anxiety and depression were also seen in 56.9% and 38.8% of patients, respectively.
The team found that 14.5% of patients were taking opioids, and 19.2% were using cannabis. Less than half (41.3%) had undergone cholecystectomy, and 6.8% a fundoplication procedure.
The most common presenting symptom was nausea, in 89.1% of patients, followed by abdominal pain in 76.4%, constipation in 70.5%, and vomiting in 65.8%.
Related treatments included at least one pyloric injection of botulinum toxin in 13% of patients, whereas 2.4% had a gastric electrical stimulator implanted.
Importantly, only 57.8% of the patients had received a definitive evaluation with a gastric emptying study (GES), of whom 38.3% had undergone the recommended 4-hour study, and just 6.8% had ingested radiolabeled eggs as the test meal, the study notes.
Besides FD, alternative final diagnoses included rapid gastric emptying (12.1% of patients), pelvic floor dysfunction (9.9%), constipation (8.4%), and cannabinoid hyperemesis syndrome (7%).
Patient Differences Found
Compared with patients with a definitive GP diagnosis, patients with alternative diagnoses were younger (P = .001) and had a lower median body mass index (P = .017).
Patients who were correctly diagnosed with GP more often had diabetes (P < .001) and a history of Barrett’s esophagus (P = .042) and were less likely to have chronic kidney disease (P = .036) and rheumatoid arthritis (P = .035).
Patients with confirmed GP were also more likely to have undergone cholecystectomy (P = .008), fundoplication (P = .025), and botulinum toxin injection of the pylorus (P = .013) than those with an alternative diagnosis. They were also more likely to use a proton pump inhibitor (P < .001), and less likely to use less cannabis (P = .034).
After tertiary evaluation, patients with a definitive diagnosis of GP were more likely to be treated with metoclopramide (P < .001), prucalopride (P < .001), ondansetron (P = .005), promethazine (P = .05), and dietary interventions (P = .024), than those with alternative diagnoses.
On the other hand, patients with alternative diagnoses more often received a tricyclic antidepressant (P = .039) and were advised to discontinue cannabis (P = .05) than those confirmed as having GP.
“Striking” Finding
Although researchers predicted that GP was overdiagnosed in the community, the finding that nearly 80% of people referred for tertiary evaluation did not have the condition was “quite striking,” Cangemi told Medscape Medical News.
The findings regarding gastric emptying evaluations highlight the result of a previous study “demonstrating low compliance with gastric emptying protocol guidelines among US medical institutions,” the researchers write.
“Improperly performed GES appears to play a critical role in misdiagnosis of GP,” they add.
The study’s main message is the “importance of performing a proper gastric emptying study,” Cangemi said. If GES isn’t conducted according to the guidelines, the results may be “misleading,” he added.
Another key point is that FD is a much more prevalent disorder, affecting approximately 10% of the US population, while GP is “much rarer,” Cangemi said.
“That might be another reason why patients are mislabeled with gastroparesis — the lack of recognition of functional dyspepsia as a common disorder of gut-brain interaction — and perhaps some hesitation of among some providers to make a confident clinical diagnosis of functional dyspepsia,” he said.
Moreover, Cangemi said, patients can “go back and forth” between the two disorders. A recent study demonstrated that roughly 40% of patients transition between the two over the course of a year, he noted.
“So being locked into one diagnosis is, I think, not appropriate anymore. Providers really need to keep an open mind and think critically about the results of a gastric emptying study, especially if it was not done recently and especially if the test did not adhere to standard protocol,” he said.
No funding was declared. Co-author Brian E. Lacy, MD, PhD, declared relationships with Ironwood, Urovant, Salix, Sanofi, and Viver. No other relevant financial relationships were declared.
Clin Gastroenterol Hepatol. February 3, 2023. Abstract
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