TOPLINE:

Multimodal profiling — combining autonomic testing, body surface gastric mapping (BSGM), and gastric emptying — revealed autonomic dysfunction in patients with chronic gastroduodenal symptoms. Autonomic dysfunction was associated with delayed gastric emptying and altered meal responses and was often noted with normal mapping.

METHODOLOGY:

• Gastric emptying testing is widely used to assess gastroduodenal function but has temporal variability, inconsistent symptom correlations, and limited sensitivity; multimodal physiologic profiling may aid in distinguishing pathophysiologic subgroups.
• Researchers conducted a prospective observational cohort study at Stanford Health in the US, including adults with chronic gastroduodenal symptoms and negative upper endoscopy, to assess the effect of autonomic dysfunction in gastroduodenal disorders using multimodal physiologic profiling — combining autonomic testing, BSGM, and gastric emptying.
• Autonomic testing by a board-certified autonomic neurologist included heart rate variability testing with deep breathing, the Valsalva maneuver, head-up tilt testing, and quantitative sudomotor axon reflex testing.
• Gastric emptying scintigraphy used a ~255-kcal low-fat ^99mTc-labeled egg meal, with delayed emptying defined as > 10% retention at 4 hours; gastroparesis required cardinal symptoms plus delayed emptying.
• BSGM was recorded using Gastric Alimetry (Alimetry Ltd.), encompassing 30 minutes of fasting, a 10-minute meal, and a 4-hour postprandial period, and phenotypes were noted for spectral metrics including the Gastric Alimetry Rhythm Index, Principal Gastric Frequency, BMI-adjusted amplitude, and meal response ratio. Symptoms such as early satiation, nausea, bloating, upper gut pain, heartburn, and excessive fullness were assessed every 15 minutes using 0-10 visual analog scales, with the combined scores used to create a “Total Symptom Burden Score.”

TAKEAWAY:

• Researchers included 80 patients with chronic gastroduodenal symptoms and negative upper endoscopy (median age, 39.5 years; 79% female), of whom 33.8% had gastroparesis, and 56.8% of those who underwent quantitative autonomic testing (n = 37) had autonomic dysfunction.
• Autonomic dysfunction and abnormal BSGM were more common in patients with gastroparesis (51.9% vs 13.2%; P = .001 and 44.4% vs 15.1%; P = .005, respectively), yet the overlap was limited, with most cases of autonomic dysfunction showing normal BSGM.
• Autonomic dysfunction was independently associated with delayed gastric emptying after considering patient demographics and gastric myoelectrical abnormalities (adjusted odds ratio [aOR], 13.8; P < .001). High Principal Gastric Frequency showed the strongest link with gastroparesis among spectral phenotypes (aOR, 28.13; P = .005), after adjustment for age.
• Autonomic dysfunction was linked to an altered postprandial meal response on BSGM occurring in the first 2 hours (median meal response ratio, 1.3 vs 1.1; P = .02). Gastric amplitude, frequency, and rhythm were similar in patients with and without autonomic dysfunction. When BSGM was normal, patients had higher levels of postprandial distress (P for early satiation = .006, P for excessive fullness = .03, and P for heartburn = .02).

IN PRACTICE:

“[A]utonomic dysfunction likely contributes to chronic gastroduodenal symptoms, particularly in a large subset of gastroparesis patients where gastric myoelectrical function is normal. These findings underscore the need for comprehensive physiological evaluations that go beyond gastric emptying testing — including both autonomic function and gastric myoelectrical assessments — to more comprehensively subtype patients to inform personalized care,” the authors of the study wrote.

SOURCE:

The study was led by Chris Varghese, Department of Surgery, University of Auckland, Auckland, New Zealand. It was published online in the American Journal of Gastroenterology.

LIMITATIONS:

All participants did not undergo formal autonomic testing. Referrals were based on specialist clinical suspicion, and patients with isolated gastric symptoms were not included. The cohort was relatively young and predominantly female. The analysis was not powered to evaluate specific metrics.

DISCLOSURES:

The research was supported by grants from the Health Research Council of New Zealand and the New Zealand Society of Gastroenterology (Janssen Research Fellowship). Two authors reported holding grants and intellectual property, and along with three other authors, reported being members of University of Auckland spinout companies. Another author disclosed being a consultant for various companies including Aclipse, Ardelyx, and Novo Nordisk.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.