Table 1.
Characteristics of the selected studies in our systematic review
| Ref. | Location | Study design and type of intervention | DM patients, n (HP+/HP-)1 | Diagnosis of H. pylori | Parameter(s) measured | Glycemic control (HP+ vs HP-) | Quality score2 |
| de Luis et al[43], 2000 |
Spain |
Observational; |
13 (13/13) |
UBT and serologic test |
HbA1c |
ND |
9 |
| before and after eradication (6-mo-follow-up) | |||||||
| Arslan et al[28], 2000 |
Turkey |
Observational; |
88 (49/39) |
Serologic test |
HbA1c |
ND |
8 |
| HP+ vs HP- | |||||||
| Ko et al[29], 2001 |
Hong Kong, China |
Observational; |
63 (32/31) |
RUT |
HbA1c and FPG |
ND |
9 |
| HP+ vs HP- | |||||||
| Jones et al[30], 2002 |
Australia |
Observational; |
63 (15/48) |
Serologic test |
HbA1c |
ND |
9 |
| HP+ vs HP- | |||||||
| Ojetti et al[18], 2002 |
Italy |
Observational; |
34 (13/21) |
UBT and histology |
HbA1c |
Worse |
7 |
| reinfected vs not reinfected (1-yr-follow-up) | |||||||
| Candelli et al[31], 2003 |
Italy |
Observational; |
121 (34/87) |
UBT and serologic test |
HbA1c |
ND |
8 |
| HP+ vs HP- | |||||||
| Wang et al[32], 2003 |
China |
Observational; |
94 (75/19) |
Serologic test |
HbA1c and FPG |
ND |
8 |
| HP+ vs HP- | |||||||
| Candelli et al[33], 2004 |
Italy |
Observational; |
58 (29/29) |
UBT |
HbA1c |
ND |
8 |
| HP+ vs HP- | |||||||
| before and after eradication (6-mo-follow-up) | |||||||
| Agrawal et al[38], 2005 |
India |
Observational; |
80 (50/30) |
RUT |
FPG |
Worse |
8 |
| HP+ vs HP- | |||||||
| Moghimi et al[41], 2007 |
Iran |
RCT |
41 (22/19) |
UBT |
HbA1c decrease and FPG decrease |
ND |
3 (Jadad score) |
| eradication vs non-eradication (3-mo-follow-up) | |||||||
| Ojetti et al[19], 2007 |
Italy |
Observational; |
40 (11/29) |
UBT and histology |
HbA1c |
Worse |
7 |
| reinfected vs not reinfected (5-yr-follow-up) | |||||||
| Toporowska-Kowalska et al[34], 2007 |
Poland |
Observational; |
198 (48/150) |
UBT |
HbA1c |
Worse |
7 |
| HP+ vs HP- | |||||||
| Khalil et al[44], 2007 |
Belgium |
Observational; |
100 (49/51) |
UBT |
HbA1C |
ND |
7 |
| before and after eradication (12-mo-follow-up) | |||||||
| Demir et al[35], 2008 |
Turkey |
Observational; |
141 (87/54) |
RUT and histology |
HbA1c and FPG |
ND |
9 |
| HP+ vs HP- | |||||||
| Lu et al[40], 2010 |
China |
Observational; |
80 (49/31) |
UBT and histology |
Insulin and C-peptide |
Worse |
8 |
| HP+ vs HP- | |||||||
| Candelli et al[17], 2012 |
Italy |
Observational; |
69 (17/52) |
UBT |
HbA1c |
ND |
8 |
| HP+ vs HP- | |||||||
| Wei[39], 2012 |
China |
Observational; |
68 (38/30) |
RUT |
FPG |
Worse |
7 |
| HP+ vs HP- | |||||||
| Zhou et al[36], 2012 |
China |
Observational; |
180 (84/96) |
Serologic test |
HbA1c, insulin and C-peptide |
ND |
8 |
| HP+ vs HP- | |||||||
| Vafaeimanesh et al[42], 2013 |
Iran |
RCT; |
93 (46/47) |
UBT |
HbA1c decrease and FPG decrease |
ND |
3 (Jadad score) |
| eradication vs noneradication (6-mo-follow-up) | |||||||
| Peng et al[37], 2013 |
China |
Observational; |
85 (43/42) |
RUT and histology |
HbA1c and FPG |
Worse |
7 |
| HP+ vs HP- | |||||||
| Wada et al[45], 2013 | Japan | Observational; |
72 (72/72) | UBT and histology | HbA1c | ND | 7 |
| before and after eradication (6-mo-follow-up) |
HP+ includes those who did not receive/failed eradication treatment, and those who were reinfected; HP- includes those who received successful eradication treatment;
Quality score is presented in each study by reference to Quality Assessment Forms, except for the two RCTs assessed using the Jadad Scale. DM: Diabetes mellitus; FPG: Fasting plasma glucose; HbA1c: Glycosylated hemoglobin; HP+: Helicobacter pylori-positive; HP-: H. pylori-negative; ND: No difference; RCT: Randomized controlled trial; RUT: Rapid urease test; UBT: 13C-urea breath test.