Helicobacter pylori infection and asthma: Is there a direct or an inverse association? A meta-analysis

Table 1 Association between Helicobacter pylori infection and Asthma in paediatric population

Ref.	Method for assessing H. pylori infection	Association	No. of asthmatic/No. of control	Age	Quality
Annagür et al[17]	Serological	Seropositivity was similar in acute exacerbations and stable asthmatics	79/36	5-15	3/5
Zevit et al[18]	13C-urea breath test	Inverse association between H. pylori and pediatric asthma	578/6381	5-18	5/5
Khamechian et al[19]	Biopsy samples	Inverse association between H. pylori and pediatric asthma	36/264	5-18	4/5
Karimi et al[20]	13C-urea breath test	Similar prevalence in cases and controls	98/98	< 18	2/5
den Hollander et al[4]	Serological	Positive association between H. pylori CagA- and pediatric asthma	3062/0	6	3/5

H. pylori: Helicobacter pylori; CagA: Cytotoxin-associated gene A.

Table 2 Association between Helicobacter pylori infection and Asthma in adult population

Ref.	Method for assessing H. pylori infection	Association	No. of asthmatic/No. of control	Age	Quality
Bodner et al[3]	Serological	Seropositivity was similar in cases and controls	19/190	39-45	3/5
Tsang et al[22]	Serological	Seropositivity was similar in cases and controls	90/97	42.6 ± 16	2/5
Jun et al[14]	Serological	Seropositivity was similar in cases and controls (also for CagA)	46/48	51.2 ± 12.4	2/5
Chen et al[23]	Serological	H. pylori+ CagA+ were less likely to have ever been diagnosed as having asthma	525/7058	Adults	3/5
Chen et al[24]	Serological	Statistical significance only in age 3-13 yr	946/6466	≥ 3	3/5
Reibma et al[25]	Serological	H. pylori+ CagA+ were less likely to have ever been diagnosed as having asthma	318/208	18-64	3/5
Shiotani et al[26]	Serological	Seropositivity was similar in cases and controls	6/771	New university students	2/3
Fullerton et al[27]	Serological	Seropositivity was similar in cases and controls	62/151	44.6 ± 13.5	3/5
Lim et al[28]	Serological	Statistical significance only in age < 40 yr	359/14673	18-91	3/5

H. pylori: Helicobacter pylori; CagA: Cytotoxin-associated gene A.