Gastroparesis, a syndrome in which patients experience delayed gastric emptying, is characterized by symptoms such as nausea, vomiting, bloating, abdominal pain, and early satiety. While gastroparesis can present as a complication of diabetes and gastric surgery, the underlying cause is unknown in many cases. Despite the significant morbidity of the condition, research and characterization of the clinical features of gastroparesis are limited, hindered by challenges such as single centers and small study populations. The Gastroparesis Registry is an observational study created by the Gastroparesis Clinical Research Consortium (GpCRC) to enroll a sufficiently large number of patients to elucidate the etiology and clinical features of the condition.

Individuals with symptoms of gastroparesis of at least 12 weeks duration, delayed gastric emptying on scintigraphy, and no abnormality causing obstruction on upper endoscopy were enrolled. Data was collected on medical history, physical examinations, upper endoscopy results, and 4 hour gastric emptying scintigraphy results. Symptoms of gastroparesis and psychological functioning were assessed using patient-completed questionnaires, including the Patient Assessment of Upper Gastrointestinal Disorders Symptoms Severity Index (PAGI-SYM), the Beck Depression Inventory (BDI), and the State-Trait Anxiety Inventory (STAI). Laboratory tests were obtained to measure complete blood count with erythrocyte sedimentation rate (ESR) and C reactive protein (CRP).

Analyses were done to examine such baseline characteristics as demographics, lifestyle, co-morbidities, laboratory values, psychological evaluation test scores, gastroparesis-specific medical history, gastric emptying scintigraphy results, and symptom severity among all patients and among various patient sub-groups. Comparisons were also done to evaluate the similarities and differences of the diabetic and idiopathic presentations of gastroparesis. Results showed that IG is a diverse syndrome that varies by sex, body mass, symptom onset, and delay in gastric emptying. Following conclusion of the GpR study, a follow-up study was initiated to expand the registry (GpR 2).

The primary objectives of the study included investigating the etiology of gastroparesis and elucidating the clinical features and outcomes of the condition.

Individuals of at least 18 years of age who met the following criteria were eligible for enrollment:

• Symptoms of gastroparesis of at least 12 weeks duration (do not have to be contiguous) with varying degrees of nausea, vomiting, abdominal pain, early satiety, and post-prandial fullness
• Completion of a 4-hour scintigraphic gastric emptying study (for classification of definite gastroparesis or gastroparesis-like with normal gastric emptying)
• No abnormality causing obstruction on upper endoscopy

Exclusion criteria are documented in the study protocol.

Analyses were done to examine such baseline characteristics as demographics, lifestyle, co-morbidities, laboratory values, psychological evaluation test scores, gastroparesis-specific medical history, gastric emptying scintigraphy results, and symptom severity among all patients and among various patient sub-groups. Comparisons were also done to evaluate the similarities and differences of the diabetic and idiopathic presentations of gastroparesis. Results showed that IG is a diverse syndrome that varies by sex, body mass, symptom onset, and delay in gastric emptying. Following conclusion of the GpR study, a follow-up study was initiated to expand the registry (GpR 2).