Table 2. Summary of studies performed on diabetic patients for the assessment of gastric emptying.

GE: gastric emptying; GI: gastrointestinal; DM: diabetes mellitus

Reference	Study design	Cases of diabetes	Observation	Study population	Methods used	Conclusion
Bharucha et al. (2015) [16]	Randomized controlled trial	78 patients	GE – average: 37 (50%), delayed: 35 (47%), rapid: 2 (3%)	Participants with type 1 diabetes	Gastric emptying assessed by 13C-spirulina breath test	Early and long-term hyperglycemia was strongly associated with delayed GE and GI symptoms
Frøkjær et al. (2007) [17]	Case-control study	Type 1 diabetics: 12, healthy controls: 12	Type 1 diabetics: increased frequency of distension-induced contractions (6.0 ± 0.6) vs. (3.3 ± 0.5) p<0.001		Esophageal and duodenal contractions were measured using bag distension and ultrasound probe	An impaired contractile activity in type 1 diabetes patients due to autonomic neuropathy
Bharucha et al. (2009) [24]	Comparative analysis	129 patients	GE – average: 55 (42%), delayed: 46 (36%), rapid: 28 (22%)		GE transit assessed by scintigraphy	Rapid and slow GE is associated with diabetes
Choung et al. (2011) [25]	Prospective, cohort study	Type 1 DM: 227, type 2 DM: 360, controls (age and sex-matched non-diabetics): 639	Cumulative proportion of developing gastroparesis in 10 years – type 1 DM: 5.2%, type 2 DM: 1.0%, controls: 0.2%	A resident population of Olmsted County	Cox proportional hazard modeling	Increased risk of gastroparesis in type 1 diabetes, but otherwise uncommon