Is Helicobacter pylori infection associated with glycemic control in diabetics?

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 ofH. 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)

¹HP+ includes those who did not receive/failed eradication treatment, and those who were reinfected; HP- includes those who received successful eradication treatment;

²Quality 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.