Table 2.

Determining the odds ratio with the confidence interval of association between Helicobacter pylori infection and metabolic syndrome and insulin resistance in case–control studies based on variables of detection methods of infection, study populations, age, body mass index, and the continents of the world

Subgroup		Number of studies	Summery odds ratio (95% CI)	Between studies			Between subgroups
				I2	P heterogeneity	Q	Q	P heterogeneity
Metabolic Syndrome	Method of bacteria detection
	Anti- H. pylori antibody	5	1.26 (1.01–1.70)	0.0%	0.852	1.38	0.19	0.910
	Rapid urease test	1	1.26 (0.53–3.00)	–	–	–
	C urea breath test (UBT)	5	1.17 (0.02–1.35)	0.0%	0.830	1.49
	BMI						0.13	0.71
	< = 24	3	1.25 (0.92–1.69)	0.0%	0.731	0.62
	> 24	5	1.36 (1.01–2.00)	0.0%	0.977	1.63
	Age							0.56
	< = 45	5	1.16 (1.00–1.35)	0.0%	0.771	1.78	0.32	0.32
	> 45	6	1.26 (1.00–1.89)	0.0%	0.964	0.96
Insulin Resistance	Method of bacteria detection
	Anti- H. pylori antibody	7	1.63 (1.25–2.12)	0.0%	0.990	2.71	0.44	0.661
	Rapid urease test (RUT) & Histology	3	1.33 (0.56–3.16)	67.1%	0.043	6.64
	Type of diabetes
	Diabetes dellitus	5	1.19 (1.00–1.78)	0.0%	0.890	4.37	3.33	0.192
	Gestational diabetes	1	2.80 (0.39–19.92)	–	–	–
	NIDDM	4	1.80 (1.34–2.42)	0.0%	0.510	2.33
	Population
	Male	4	1.19 (1.00–1.78)	0.0%	0.990	0.08	0.23	0.89
	Female	4	2.80 (0.39–19.92)	0.0%	0.940	0.38
	Both	7	1.80 (1.34–2.42)	44.1%	0.152	9.36
	Continent
	Asia	5	1.67 (1.23–2.26)	0.0%	0.764	1.85	1.72	0.63
	America	7	1.47 (0.89–2.44)	0.0%	0.930	0.58
	Africa	2	1.00 (0.26–3.77)	47.6%	0.173	1.91
	Europe	1	2.35 (1.16–4.73)	–	–	–
	BMI
	< = 29	5	1.04 (0.60–1.79)	12.2%	0.488	3.46	0.84	0.36
	> 29	7	1.47 (0.89–2.44)	0.0%	0.662	0.55
	Age
	<= 45	8	1.09 (0.70–1.70)	2.5%	0.770	4.05	0.99	0.77
	> 45	7	1.77 (1.35–2.33)	0.0%	0.872	2.40

OR: odds Ratio, I²: I Square, Q: Q Cochrane Test, CI: confidence interval, BMI: body mass index