Table 1 Characteristics of included studies in the meta-analysis

Muraleedharan [28]

2021

India

Case–control

40/40

24.98/24.55

34.50/ 34.50

3.76/2.30

1.28/1.62

11.59/13.63

2.12/2.43

1.16/1.33

8

Maduka [29]

2020

Nigeria

Case–control

40/40

31.5/29.5

N/A^a

0.95/1.3

290/350

33.2/19.35

7.00/7.65

11.3/13.5

7

Abdal latief [30]

2020

Egypt

Case–control

30/ 30

23.69/ 25.30

34.14/ 34.07

5.18/1.96

N/A

N/A

4.07/3.53

0.99/1.12

8

Patil(a) [31]

2020

India

cross sectional

40/40

23.25/23.73

34.33/36.15

3.99/2.32

N/A

N/A

3.06/3.41

2.26/2.23

7

Patil(b) [31]

2020

India

cross sectional

40/40

22.25/23.73

33.10/36.15

5.66/2.32

N/A

N/A

2.77/3.41

2.34/2.23

7

Kumar [32]

2020

India

Case–control

100/100

22..02/ 22.11

34.54/ 36.13

4.21/ 1.98

118.11/131

7.84/ 11.87

N/A

N/A

8

Misra [33]

2020

India

Case–control

80/90

24.33/23.00

36.7/37.6

5.07/3.30

N/A

N/A

2.67/2.56

1.15/1.00

8

Bozkurt [34]

2020

Turkey

Retrospective

45/72

28.5/27.1

N/A^a

2.4/2.3

N/A

N/A

2.6/2.6

0.9/ 0.9

7

Bozkurt [34]

2020

Turkey

Retrospective

27/72

30.3/27.1

N/A^a

2.2/2.3

N/A

N/A

2.3/2.6

0.9/ 0.9

7

Marwa(a) [35]

2019

Iraq

Case–control

29/48

32.95/33.98

32.95/33.98

2.76/2.44

1.32/1.53

7.65/8.95

N/A

N/A

8

Marwa(b) [35]

2019

Iraq

Case–control

29/48

32.95/33.98

32.95/33.98

3.82/2.44

1.32/1.53

7.40/8.95

N/A

N/A

8

Prashanthi [36]

2019

India

Case–control

100/50

25.78/ 25.10

30.35/34.30

3.40/2.19

0.87/1.64

9.34/11.31

N/A

N/A

7

Tariq [37]

2018

Pakistan

Case—control

50/50

27.8/26.6

34.6/35.5

3.75/2.33

151.34/195.66

11.33/14.56

N/A

N/A

8

Sattar [3]

2018

Pakistan

Case–control

17/16

26.06/25.12

N/A

6.56/ 3.28

1.19/ 1.22

11.09/13.96

2.67/ 2.94

2.81/ 2.91

7

Murmu [38]

2018

India

Case–control

100/50

32.95/33.98

32.95/33.98

2.41/1.50

N/A

N/A

1.42/1.60

0.933/1.08

7

Chowdhary [39]

2018

India

Case–control

50/50

23.57/22.9

33.92/33.98

6.19/ 2.22

5.29/ 9.46

0.92/ 1.41

N/A

N/A

8

Ban(a) [40]

2018

Iraq

Case–control

50/100

25.1/25.0

38.8/39.1

3.23/2.1

2.30/2.70

1.46/1.79

N/A

N/A

8

Ban(b) [40]

2018

Iraq

Case–control

50/100

25.4/25.0

36.3/39.1

4.40/2.10

2.00/2.70

1.39/1.79

N/A

N/A

8

Amin [41]

2018

Pakistan

Case–control

40/40

N/A

N/A

2.65/2.25

N/A

N/A

1.44/1.48

8.75/10.09

7

Rani [42]

2018

India

Case–control

40/35

25.34/25.63

35.67/37.7

4.10/2.69

N/A

N/A

1.37/1.83

8.08/9.18

7

Murmu [43]

2018

India

Case–control

100/50

32.95/33.98

N/A

2.41/1.50

N/A

N/A

1.42/1.60

0.93/1.08

8

Muraleedharan(a) [16]

2017

India

Case–control

22/40

24.3/ 24.6

34.5/35.5

3.33/2.30

1.29/1.62

11.66/13.63

2.18/2.43

1.22/1.33

8

Muraleedharan(b) [16]

2017

India

Case–control

18/40

25.8/24.6

34.5/35.5

4.28/2.30

1.26/1.62

11.51/13.63

2.05/2.43

1.09/1.33

8

Grammatikakis [44]

2017

Greece

Retrospective analysis

60/60

29.2/28.8

37.1/38.6

4.40/2.40

N/A

N/A

3.45/2.80

0.70/0.70

7

Harshvardhan [14]

2017

India

Case–control

50/50

25.6/24.4

N/A

5.36/3.48

N/A

N/A

2.24/1.99

1.13/1.00

7

Dineshkumar [45]

2017

India

Case–control

40/40

27.4/26.64

N/A

2.79/2.42

N/A

N/A

1.54/ 1.60

10.89/11.10

7

Haldar [13]

2017

India

Case–control

100/100

N/A

N/A

4.39 /1.69

8.99/8.91

0.91/0.92

N/A

N/A

8

Jain [22]

2017

India

Case–control

40/40

26.15/26.19

N/A

8.64/4.65

11.31/14.36

150.62/ 195.6

N/A

N/A

8

Businge(a) [46]

2017

Congo

Case–control

200/150

32.4/33.5

26.9/37.7

4.10/2/70

1.30/1.20

10.70/9.90

N/A

N/A

7

Businge(b) [46]

2017

Congo

Case–control

200/150

32.4/33.5

32.5/37.7

6.60/2.70

1.50/1.20

11.40/9.90

N/A

N/A

7

Rajalaksmi [47]

2016

India

cross sectional

200/200

24.36/ 23.99

34.7/34.9

2.90/2.25

N/A

N/A

2.21/2.4

1.24/1.35

8

Reddy [48]

2016

India

Case–control

50/50

22.94 /22.17

35.85/ 33.54

5.22/3.37

1.40/1.36

11.99/10.28

N/A

N/A

8

Tadas [49]

2016

India

Case–control

50/50

27.8/26.6

34.6/35.5

3.75/ 2.33

11.33/14.56

151.34/195.66

N/A

N/A

8

Chauhan [50]

2016

India

Case–control

50/50

27.8/26.6

34.6/35.5

3.75/ 2.33

151.34/ 195.66

11.33/ 14.56

N/A

N/A

8

Chaudhary [39]

2016

India

Case–control

60/60

23.57/22.9

33.92/33.98

4.49/ 2.95

1.10/ 1.47

6.54/ 8.46

N/A

N/A

8

Procopciuc(a) [51]

2016

Romania

Case–control

57/131

29.07/28.41

34.72/38.79

3.26/2.34

N/A

N/A

2.44/2.85

1.19/0.97

7

Procopciuc(b) [51]

2016

Romania

Case–control

32/131

5.24/2.34

N/A

N/A

2.28/2.85

1.54/0.97

7

Umadevi [52]

2015

India

Case—control

200/200

24.36/ 23.99

34.7/ 34.9

2.90/ 2.25

N/A

N/A

2.21/ 2.4

1.24/ 1.35

8

Thanna [9]

2015

India

Case–control

30/30

25.25 /24.34

N/A

7.89 /3.22

1.18 /1.27

9.78/8.96

N/A

N/A

8

Sogani [15]

2015

India

Case–control

35/35

22.94/ 23.17

35.85/ 38.54

6.22/3.35

1.39/1.38

10.99/10.26

N/A

N/A

8

Rafeeinia [53]

2015

Iran

Case–control

50/50

26.5 /27.1

31.24 /30.17

2.30/1.82

4.00/3.90

5.03/5.02

N/A

N/A

8

Deshpande [54]

2015

India

Case–control

100/100

23.08/ 22.78

36.99/ 38.07

3.14/1.92

N/A

N/A

3.08/3.49

0.89/0.86

7

Elhaj(a) [55]

2015

Sudan

Case–control

55/55

28.1 /27.4

38.4/ 37.7

1.30/2.30

N/A

N/A

1.10/0.80

2.00/0.70

8

Elhaj(b) [55]

2015

Sudan

Case–control

55/55

29.1 /27.4

38.4/ 36.1

1.50/2.30

N/A

N/A

0.90/0.80

2.10/0.70

8

Sheela [56]

2015

India

Case–control

50/50

23.64/ 23.17

37.91/ 38.28

6.15/2.45

1.37/1.56

9.87/11.61

N/A

N/A

8

Satyanarayan [57]

2015

India

Case–control

30/30

N/A

N/A

7.22/2.48

1.25/1.21

10.16 /9.03

N/A

N/A

7

Camejo [58]

2014

Venezuela

Case–control

20/20

28.83/25.3

33.13 /35.3

2.60/2.50

N/A

N/A

2.99/3.35

1.00/1.00

8

Kaveti [59]

2014

India

Case–control

30/30

22.6/22.76

33.53/ 32.86

3.15/1.17

2.66/2.15

16.53/14.45

N/A

N/A

8

Naykı [23]

2014

Turkey

Case–control

50/30

26.84/ 28.3

35.44/ 38.03

2.41/2.51

N/A

N/A

3.23/2.96

1.58/1.28

7

Bayejid [60]

2014

Bangladesh

Case–control

27/25

25.04 /26.00

38.36/ 34.11

5.09/2.00

1.43/ 1.86

131.90/ 150.90

N/A

N/A

7

Manjunatha [61]

2014

India

Case–control

30/30

24/ 24

N/A

7.22/2.48

1.25/1.21

10.16/9.03

N/A

N/A

7

Kurlak [62]

2013

England

Cross sectional

23/27

32/29

36.4/39.9

3.4/2.5

N/A

N/A

3.7/3.7

11.2/11.9

8

Khanam [63]

2013

Bangladesh

Cross sectional

52/52

26.15/ 26.19

34.3/ 35.1

4.14/ 2.75

1.95/ 1.98

128.38/ 126.37

N/A

N/A

7

Das [64]

2013

India

Case–control

30/30

26 /27

36 /37

3.82/2.12

2.13/ 0.85

12.61/7.02

3.51/2.62

2.36/1.14

8

Monika [65]

2013

India

Case–control

25/25

N/A

N/A

3.59/2.93

1.83/2.18

101.46/101.47

N/A

N/A

8

Kharb(a) [18]

2013

India

Case–control

50/100

23.08

38.67

3.42/2.00

136.82/134.00

10.84/12.14

N/A

N/A

8

Kharb(b) [18]

2013

India

Case–control

50/100

23.01/ 23.04

36.87/ 39.09

5.63/2.00

119.64/134.00

9.39/12.14

N/A

N/A

8

Männistö [66]

2013

Finland

Prospective population-based cohort

381/4540

28.8/27.0

N/A

1.11/ 1.03

N/A

N/A

5.35/5.10

5.10/15.33

7

Procopciuc [67]

2012

Romania

Cohort

50/50

28.58 /28.04

35.36 /38.64

2.76/2.19

N/A

N/A

2.63/2.91

1.11/0.88

8

Alavi [68]

2012

Iran

Case–control

48/50

22.38/ 22.18

37.02/ 38.26

2.03/2.17

152.5/175.36

8.72/9.39

N/A

1.28/1.00

8

Riah(a) [69]

2012

Egypt

Prospective cross sectional

20/20

27.0/27.4

37.3/38.7

2.80/2.06

N/A

N/A-

1.40/1.50

0.90/1.00

8

Riah(b) [69]

2012

Egypt

Prospective cross sectional

20/20

28.9/27.4

36.5/38.7

4.30/2.06

N/A

N/A

1.50/1.50

1.01/1.00

8

Khadem [10]

2012

Iran

Case–control

40/40

28.0/26.0

35.57/38.5

3.51/3.10

N/A

N/A

3.51/1.41

0.95/0.96

8

Dhananjaya [70]

2011

India

Case–control

25/25

24.08/24.32

N/A

8.42/ 2.44

10.46/ 9.93

1.15/ 1.28

N/A

N/A

7

Al-Naqeeb(a) [71]

2010

Iraq

Case–control

37/30

30.05

N/A

1.14/1.12

0.89/1.21

10.81/8.69

N/A

N/A

7

Al-Naqeeb(b) [71]

2010

Iraq

Case–control

53/30

27.08/28.83

N/A

2.61/1.12

2.71/1.21

7.93/8.69

N/A

N/A

7

Obiero [72]

2010

Kenya

Case–control

35/35

28.7/28.1

32.1/31.4

2.51/1.53

N/A

N/A

1.94/2.04

12.39/14.01

7

Sardana [73]

2009

India

Case–control

100/100

23.7/23.04

37.77/39.09

4.52/2.00

128.23/134

10.12/12.14

N/A

N/A

8

Pasupathi [74]

2009

India

Case–control

30/30

27/28

35/36

5.25/ 3.89

1.85/ 2.17

12.75/ 12.62

2.72/ 3.57

2.42/ 2.38

7

Kumar [75]

2005

India

Case–control

82/82

28.4/27.5

34.3/35.1

4.6/ 2.5

N/A

N/A

3.1/ 2.7

0.8/ 0.9

8

Larijani(a) [76]

2004

Iran

Case–control

17/42

26.97/27.09

35.67/34.08

1.59/1.04

203.41/209.71

10.71/13.5

3.55/4.71

2.98/6.44

8

Larijani(b) [76]

2004

Iran

Case–control

22/42

27.07/27.09

34.02/34.08

1.54/1.04

203.13/209.71

12.73/13.5

5.45/4.71

8.82/6.44

8

Basbug [77]

1999

Turkey

Case–control

37/20

23.7/24.8

35.4/38.3

2.96/1.55

141.16/180.58

10.00/13.76

2.41/3.32

1.1/1.45

7

Khaliq [78]

1999

India

Case–control

32/10

N/A

N/A

3.77/ 2.34

150.62/ 195.6

11.31/ 14.36

N/A

N/A

7

Kaya [79]

1994

Turkey

Case–control

45/45

27.6/27.0

35.6/ 37.2

2.00/ 1.50

156/ 196

11.8/ 14.7

N/A

N/A

8

Lao [80]

1990

Hong Kong

Case–control

39/24

N/A

N/A

3.9/2.5

1.9/2.1

118.8/131.6

2.8/3.3

12.5/16.3

7

Lao [81]

1988

Hong Kong

Case–control

24/24

28.4/27.5

37.5/39.3

3.9/2.5

1.9/2.1

118.8/131.6

2.8/3.3

12.5/16.3

8