Asymptomatic small intestinal ulcerative lesions: Obesity and Helicobacter pylori are likely to be risk factors

Table 1 Reports of pretest small intestinal mucosal breaks in normal volunteers

Country	Year	No.	Subjects with mucosal breaks		Mean number of mucosal breaks		Ref.
			Number	%	Subjects with MB	All subjects
United States	2005	413	571	13.81	N/A	N/A	Goldstein et al[10], 2005
United States	2007	472	56	11.9	N/A	N/A	Goldstein et al[11], 2007
Japan	2009	32	3	9.4	1.7	0.16	Fujimori et al[12], 2009
Canada	2009	20	0	0	0	0	Smecuol et al[13], 2009
Japan	2010	20	2	10.0	1-2	0.1-0.2	Shiotani et al[14], 2010
Japan	2011	72	4	5.6	1.0	0.56	Fujimori et al[4], 2011
Japan	2013	32	N/A	N/A	N/A	0.1-0.3	Kuramoto et al[15], 2013
China	2014	30	2	6.7	3.5	0.23	Huang et al[16], 2014
Japan	2014	30	N/A	N/A	N/A	0.14 ± 0.54	Umegaki et al[17], 2014
Japan	2016	141	14	9.9	3.5	0.35	Fujimori et al[5], 2016
Japan	2015	37	N/A	N/A	N/A	0.1-0.3	Kojima et al[18], 2015
Czech	2016	42	2	4.7	N/A	N/A	Tachecí et al[19], 2016
Japan	2016	19	2	10.5	1.0	0.11	Arimoto et al[20], 2016
Japan	2016	45	N/A	N/A	N/A	0.13	Ota et al[21], 2016
Japan	2019	24	0	0	0	0	Ota et al[22], 2019

¹Lesion type unknown. Reports with 15 or more subjects and reports on premedication lesions were collected. MB: Mucosal break; N/A: Not available.

Table 2 Basic background of the two examinations whose background was examined in detail

Ref.	Number	Sex (M/F)	Age (mean ± SD)	Mean mucosal break
Fujimori et al[4], 2011	77	77/0	38.2 ± 8.1	0.12 ± 0.32
Fujimori et al[5], 2016	145	71/74	48.6 ± 6.4	0.30 ± 1.47
Total	222	148/74	45.0 ± 8.6	0.24 ± 1.21

Premedication capsule endoscopy was completed, and subjects who dropped out in subsequent studies were included.

Table 3 Analysis of mucosal breaks and background factors

Valuable	Mucosal break + (n = 21)	Mucosal break – (n = 201)	P value1	P value2
Sex	Male/female: 19/2	Male/female: 129/72	0.015	0.13
Age	44.0 ± 6.7	45.2 ± 8.8	0.54
BMI	24.7 ± 3.6	22.5 ± 3.0	0.022	0.0074
Smoking	5 (23.8%)	56 (27.9%)	0.69
Drinking	14 (66.7%)	140 (70.0%)	0.78
Helicobacter pylori	8 (38.1%)	13 (6.4%)	0.054	0.035

¹Sex, smoking, alcohol consumption, and Helicobacter pylori were analyzed by the chi-square test, and age and body mass index were analyzed by the Mann-Whitney U test.

²P value by logistic multivariate analysis. BMI: Body mass index.

Table 4 Disease and/or cause of small intestinal ulcer with multiple reports

Category	Disease and/or cause	Ref.
Inflammatory disease	Crohn’s disease	Gomollón et al[3], 2017
	Behçet's disease	Lee et al[23], 2012
	polyarteritis nodosa	Perlemuter et al[24], 1996
	Schönlein-Henoch purpura	Nishiyama et al[25], 2008
Vascular disease	Ischemic enteritis	Iwai et al[26], 2018
Systemic disease	Amyloidosis	Tada et al[27], 1994
Heridetary disease	Chronic enteropathy associated with SLCO2A1 gene	Umeno et al[28], 2015
Bacterial infection	Yersinia enterocolitica	Matsumoto et al[29], 1990
	Campylobacter jejuni	Duffy et al[30], 1980
	Salmonella typhi	Goel et al[31], 2017
	Salmonella typhmurium	Boyd[32], 1985
	Salmonella enteritidis	Dworkin et al[33], 2001
	Mycobacterium tuberculosis	Lu et al[34], 2020
Viral infection	Epstein-Barr virus	Watanabe et al[35], 2020
	Cytomegalovirus	Matsumura et al[36], 2020
	COVID-19	Sahu et al[37], 2021
Drug induced	Various drugs included NSAIDs	Scarpignato and Bjarnason[38], 2019
Immunodeficiency	Acquired immunodeficiency syndrome	Zeitz et al[39], 1998
	Graft-versus-host disease	Peled et al[40], 2016

Reference searched as much as possible for new, review, and important ones. COVID-19: Coronavirus disease-2019; NSAID: Nonsteroidal anti-inflammatory drugs.