Selection of eligible studies
A total of 4597 articles were obtained in the initial search. After removal of 478 due to duplicates, 4119 were remained and screened for titles and abstracts. Following this, 4018 studies were removed after reading their titles and abstracts. The full texts of 101 articles were downloaded and assessed for eligibility criteria. Seventy six articles [33–108] were included in the final analysis in this meta-analysis. Twenty five studies were excluded due to the following exclusion criteria: different study population [109–113], no full test [114–117], unclear diagnostic criteria [118–125], letter to editor [126], written in non English language [127, 128], and different study design [129–133] (Fig. 1).
Characteristics Of The Included Studies
All of the studies included in this study were cross-sectional studies were cohort studies. Regarding study population, 20 studies [35, 47, 50, 55, 57, 58, 63, 69, 71, 72, 77, 79, 84, 87–89, 91, 92, 95, 104] were conducted among overweight and/or obese children and adolescents, and 56 studies [33, 34, 36–46, 48, 49, 51–54, 56, 59–62, 64–68, 70, 73–76, 78, 80–83, 85, 86, 90, 93, 94, 96–103, 105–108] were conducted among the general population of children and adolescents. This review included 142,142 study participants from 76 articles. Of which, 138,236 were general population, whereas 3906 were overweight and obese population. The sample size of included studies ranged from 51in Tunisia [58] to 37504in Brazil [52]. The age of study population accross the included studies ranged between 5 to 20 years. Most of the studies were conducted in UMIE Asian countries and very few articles were found from Africa. The quality of articles was also assessed using the JBI checklist, and 56 articles had medium quality. The remaining 20 studies had high quality (Table 2, Table 3)
Table 2
Characteristics of studies used to compute the prevalence of metabolic syndrome in LMICs in overweight/obese adolescents
Author, year | Country | Sample size | Prevalence of MetS | Age | MetS with Diagnostic methods N (%) | Components of Mets (%) | Qaulity Scores |
M (%) | F (%) | IDF | ATP-III | de.F. | Ab. obesity | Low HDL | High TGL | High FG | High BP |
Dejavitte et al, 2020 [1] | Brazil | 354 | 142(15.5) | 212(5.7) | 10–19 | 34(9.6) | - | - | 77.4 | 49.4 | 5.6 | 15 | 1.1 | 8 |
Cornejo-Monthedoro et al, 2017 [2] | Peru | 273 | 143(19.6) | 130(25.4) | 10–15 | 61(22.3) | - | - | 81.7 | 63.7 | 29.7 | 5.9 | 5.1 | 8 |
Rinaldi et al, 2016 [3] | Brazil | 147 | 71(12.7) | 76(7.9) | 6–10 | - | 15(10.2) | - | 47.6 | 24.5 | 23.8 | 0.8 | 11.6 | 8 |
Vukovic et al, 2015 [4] | Serbia | 199 | 84(33) | 115(29.6) | 4–19 | 62 (31.2) | - | - | 9.1 | 45.3 | 15.7 | 4.3 | 34.6 | 6 |
Medina et al, 2015 [5] | Mexico | 137 | 67(28.4) | 70(17) | 6–12 | - | 31(22.6) | - | 56.9 | 34.3 | 46 | 0.73 | 21.1 | 6 |
Damak et al, 2015 [6] | Tunisia | 51 | 28(21) | 23 (22) | 15–18 | 11(21.6) | - | - | 58.8 | 9.8 | - | 27.4 | 58.8 | 6 |
Tavares Giannini et a, 2014 [7] | Brazil | 163 | 52 | 111 | 10–18 | 16(9.8) | 33(20.2) | - | 85.9 | 42.3 | 29.4 | - | 13.5 | 8 |
52 | 111 | | | | | 70.5 | 23.9 | 8.6 | 1.8 | 18.4 | |
Gobato et al, 2014 [8] | Brazil | 79 | 40(52.8) | 39(47) | 10–18 | 36(45.5) | - | | - | - | - | - | - | 6 |
Casavalle et al, 2014 [9] | Argentina | 139 | 78 | 61 | 8–14 | - | 30 (21.6) | - | 55.4 | 29.5 | 31.7 | 1.5 | 25.2 | 6 |
Yee et al, 2013 [10] | Myanmar | 46 | 25 | 21 | 5–12 | 9(19.6) | - | - | 54.4 | 60.9 | 13.0 | 4.3 | 8.7 | 6 |
Sewaybrickera et al, 2013 [11] | Brazil | 65 | 32(29.1) | 33(33.3) | 10–18 | 18(27.7) | 19 (29.2) | - | 27.7 | 27.7 | 27.7 | 27.7 | 27.7 | 5 |
32(25) | 33(33.3) | 10–18 | | | | 27.7 | 29.2 | 29.2 | 27.7 | 29.2 | |
Rizzo et al, 2013 [12] | Brazil | 321 | 147(18.4) | 174(18.4) | 10–16 | 59 (18.3) | - | - | 55 | 35.5 | 18.5 | 2 | 21 | 6 |
Saffari et al, 2012 [13] | Iran | 100 | 42 (57) | 58(67) | 6–16 | - | 63(63) | - | 81 | 70 | 74 | 12 | 36 | 5 |
Jamoussi t al, 2012 [14] | Tunisia | 186 | 49(40.8) | 137(32) | 6–18 | 64(34.4) | - | - | 100 | 27 | 15 | 51 | 28 | 5 |
Cua et al, 2012 [15] | Philippines | 350 | 206(20) | 144(18) | 10–18 | 67(19) | - | - | 98 | 17 | 24 | 12 | 25 | 6 |
Costa et al, 2012 [16] | Brazil | 121 | 62 | 59 | 10–14 | 48(39.7) | 62(51.2) | 90(74.4) | 81 | 54.5 | 16.5 | 7.4 | 54.5 | 6 |
62 | 59 | 10–14 | | | | 81 | 54.5 | 34.7 | 1.7 | 76 | |
62 | 59 | 10–14 | | | | 96.7 | 92.6 | 40.5 | 1.7 | 76 | |
Hassan et al, 2011 [17] | Egypt | 462 | 144 | 288 | 7–18 | - | - | 184(39.7) | 85.7 | 32 | 42.9 | 13.9 | 30.3 | 6 |
Panamonta et al, 2010 [18] | Thailand | 186 | - | - | 10–15 | 6 (3.2) | - | - | - | 10.2 | 28.0 | 1.1 | 8.6 | 6 |
Juárez-López etal, 2010 [19] | Mexico | 466 | 272(21) | 194(20) | 11–13 | 93(20) | - | - | 49 | 69 | 29 | 4 | 13 | 6 |
Caceres et al, 2008 [20] | Bolivia | 61 | 30(40) | 31(32) | 5–18 | - | 22(36) | - | 100 | 55.7 | 42.6 | 8.2 | 24.5 | 6 |
Table 3
Characteristics of studies included to compute the prevalence of metabolic syndrome in low and middle income countries
Author, year | Country | Sample size | Prevalence in Males (%) | Prevalence in Females (%) | Age | MetS with Diagnostic method N (%) | Population | Gender (%) | Components of Mets (%) | Quality Score |
IDF | ATP-III | de.Ferranti | Non-OB | OW/OB | M | F | Ab. Obesity | Low HDL | High TGL | High FG | High BP |
Zhu et al, 2020 [1] | China | 15045 | 7711(2.8) | 7334(1.7) | 7–18 | 346(2.3) | - | - | - | - | 1.4 | 0.9 | 21.8 | 14.4 | 5.5 | 3 | 3.7 | 6 |
Mahajan et al, 2020 [2] | India | 296 | 128(3.9) | 168(3.6) | 14–19 | - | 11(3.7) | - | - | - | 1.7 | 2.1 | 9.8 | 64.9 | 6.4 | 0.3 | 16.9 | 8 |
Bekele et al, 2020 [3] | Ethiopia | 824 | 403(10.2) | 421(14.5) | 13–19 | 102(12.4) | - | - | 6.3 | 6.1 | 5 | 7.4 | 32.2 | 20.6 | 26.2 | 57.8 | 8.5 | 6 |
Ahmadi et al, 2020 [4] | Iran | 1035 | 456(9.6) | 579(6) | 6–18 | 79(7.6) | - | - | - | - | 4.3 | 3.3 | 27.8 | 56.2 | 7.4 | 9.1 | 8 | 8 |
Zhao et al, 2019 [5] | China | 1766 | 871(4) | 895(2) | 10–15 | 59(3.3) | - | - | 0.1 | 3.2 | 2 | 1.3 | 30 | 78 4 | 10 | 11 | 7 | 8 |
Zhang et al,2019 [6] | China | 683 | 366(6.6) | 317(3.5) | 8–15 | - | 35(5.1) | - | 0.1 | 5 | 3.5 | 1.6 | - | - | - | - | - | 6 |
Wang et al, 2019 [7] | China& Spain | 2126 | 1011 | 1115 | 10–15 | 30(1.4) | - | - | - | - | - | - | 16.7 | 15.8 | 5.5 | 4.1 | 12.6 | 8 |
Oliveira et al, 2019 [8] | Brazil | 1035 | 470(5.2) | 565(3.9) | 12–20 | 47 (4.5) | - | - | 3.4 | 1.1 | 2.4 | 2.1 | 14.9 | 26.4 | 4.2 | 4.4 | 9.0 | 6 |
Suebsamran et al, 2018 [9] | Thailand | 393 | 152(5.9) | 241(1,2) | 13–16 | 12 (3.1) | 23(5.8) | 44(11.2) | 0.3 | 2.8 | 2.3 | 0.8 | 15.6 | 25.6 | 3.3 | 0.8 | 4.6 | 6 |
152(10.5) | 241(2.9) | 13–16 | | | | 1 | 4.8 | 4.1 | 1.7 | 15.6 | 28.4 | 13.7 | 0.2 | 11.7 | |
152(15.8) | 241(8.3) | 13–16 | | | | 3.1 | 8.1 | 6.1 | 5.1 | 34.6 | 51.3 | 17.8 | 0.2 | 11.7 | |
Gupta et al, 2018 [10] | India | 2100 | 1149(4.4) | 951(9) | 10–16 | 69(3.3) | 74(3.5) | - | - | - | 2.4 | 0.9 | 8.0 | 16.9 | 9.2 | 13.5 | 7.6 | 6 |
Dos Santos et al, 2018 [11] | Brazil | 274 | 88(5) | 186(4.4) | 12–18 | 13(4.7) | - | - | - | - | 1.8 | 2.9 | 15.3 | 25.2 | 6.6 | 5.1 | 8.8 | 6 |
Andaki et al,2018 [12] | Brazil | 1480 | 707(12.6) | 773(8.5) | 6–10 | - | - | 99(6.7) | - | - | 6 | 0.7 | 27.5 | 43 | 10.7 | 0.7 | 10.7 | 6 |
Sekokotla et al, 2017[13] | S.Africa | 371 | 116(6) | 255(3.1) | 13–18 | 15(4) | - | - | - | - | 1.9 | 2.1 | 30 | 28.8 | 8.6 | 4.6 | 32.6 | 6 |
Wang et al, 2016 [14] | China | 1770 | 857(1.4) | 913(0.8) | 7–17 | 19(1·1) | - | - | - | - | 0.68 | 0.42 | 11.9 | 11.6 | 5.5 | 1.6 | 0.8 | 6 |
Suarez-Ortegón et al, 2016 [15] | Colombia | 494 | 256(8.6) | 238 (8.8) | 5–9 | - | - | 43(8.7) | - | - | 4.5 | 4.2 | 33 | 47.6 | 20.4 | 4 | 2.6 | 6 |
Kuschnir et al, 2016 [16] | Brazil | 37504 | 15006 (2.9) | 22498(2.4) | 12–17 | 975(2.6) | - | - | - | - | 1.2 | 1.4 | 12.6 | 32.7 | 4.6 | 4.1 | 8.2 | 6 |
Karandish et al, 2016 [17] | Iran | 1749 | 886(8) | 863(2.9) | 10–16 | - | 96(5.5) | - | - | - | 4.1 | 1.4 | 9.2 | 25 | 31.2 | 17 | 22.8 | 8 |
de Carvalho et al, 2016 [18] | Brazil | 421 | 170 | 251 | 9–19 | 17(4.1) | - | - | - | - | - | - | 8.6 | 26.1 | 20.9 | 0.5 | 11.9 | 6 |
Ramı´rez-Ve´ lez et al, 2016 [19] | Colombia | 1922 | 877(0.11) | 1045(.48) | 9–17 | 6(0.3) | 119(6.2) | 211(11) | 0.15 | 0.15 | 0.04 | 0.26 | - | - | - | - | - | 6 |
877 | 1045 | 9–17 | | | | 4 | 2.2 | 2.5 | 3.7 | - | - | - | - | - | |
877 | 1045 | 9–17 | | | | 7 | 4 | 4.5 | 6.5 | - | - | - | - | - | |
Rosini et al, 2015 [20] | Brazil | 1011 | 481(13) | 530(15) | 6–14 | - | 143 (14.1) | - | 3 | 11.1 | 6.2 | 7.9 | 30.4 | 37.6 | 26.1 | 11.6 | 13.6 | 8 |
Bhat et al, 2015 [21] | India | 899 | 311(3.8) | 588(3.5) | 10–18 | 14(1.5) | 32(3.6) | - | 1.7 | 1.9 | 1.4 | 2.2 | 3.7 | 17 | 31 | 9.8 | 4 | 6 |
Bhalavi et al, 2015 [22] | India | 405 | 182(7.7) | 223(11.7) | 10–19 | - | 40(9.9) | - | 9.9 | - | 3.5 | 6.4 | 2.2 | 58.3 | 27.9 | 13.8 | 22.4 | 6 |
Bortoloti et al, 2015 [23] | Brazil | 683 | 301 | 382 | 11–17 | - | 37(5.4) | - | - | - | - | - | 3.5 | 44.7 | 18.6 | 0.6 | 7 | 6 |
Reyes, et al, 2014 [24] | Venezuela | 916 | 450(3.11) | 466(1.3) | 9–18 | 14 (1.5) | 20 (2.2) | - | - | - | 1.5 | 0.7 | 10.2 | 8.6 | 10.5 | 3.6 | 8.7 | 6 |
450 | 466 | 9–18 | | | | - | - | - | - | 9.5 | 31.4 | 7.5 | 3.6 | 0.7 | |
Rerksuppaphol et al, 2014 [25] | Thailand | 348 | 189(3.7) | 159(4.4) | - | - | - | 14(4)- | 0.6 | 3.4 | 2 | 2 | 29.6 | - | 12.6 | 8.9 | 18.4 | 6 |
Rashidi et al, 2014 [26] | Iran | 2246 | 1113(11) | 1133(7) | 10–19 | - | 203(9) | - | 6.1 | 2.9 | 5.5 | 3.5 | 10.3 | 24.1 | 33.5 | 16.4 | 22.1 | 6 |
Pitangueira et al, 2014 [27] | Brazil | 502 | 213(16.4) | 289(10) | 7–14 | - | 64(12.8) | - | 2.8 | 10 | 7 | 5.8 | 26.7 | 52.8 | 41.8 | 7.2 | 29.1 | 6 |
Mbowe et al, 2014 [28] | Guatemala | 302 | 144 | 158 | 8–13 | - | 6(2) | - | - | - | - | - | 12.3 | 17.2 | 43.4 | 1.7 | 2.0 | 8 |
Li et al, 2014 [29] | China | 910 | 485(10.9) | 425(3.8) | 11–16 | 69(7.6) | - | - | - | - | 5.8 | 1.8 | 22.5 | 46.8 | 9.7 | 6.3 | 16.9 | 8 |
Fadzlina et al, 2014 [30] | Malaysia | 1014 | 387(3.4) | 627(2.1) | 13 | 26(2.6) | - | - | - | 2.6 | 1.3 | 1.3 | 17.3 | 6.3 | 6.6 | 3.5 | 4.9 | 6 |
Wang et al, 2013 [31] | China | 2564 | 1279(0.4) | 1285(6.7) | 10–18 | 140(5.5) | 331(12.9) | - | - | 2.1 | 3.4 | 2.1 | 31.4 | 14.1 | 10.3 | 12.6 | 9.9 | 6 |
1279(1.0) | 1285(24.7) | 10–18 | | | | 0.5 | 12.4 | 8.1 | 4.8 | 32.6 | 11.9 | 25.3 | 12.6 | 19.4 | |
Tandona et al, 2013 [32] | India | 695 | 346 | 349 | 10–18 | 118(17) | 137(19.7) | - | 0.2 | 16.8 | - | - | 39.3 | 27.3 | 37 | 13.2 | 14 | 6 |
Sua´ rez-Ortego’n et al, 2013 [33] | Colombia | 1461 | 718(1) | 743(1.3) | 10–16 | 18(1.2) | 37(2.5) | 124(8.5) | 0.4 | 0.8 | 0.5 | 0.7 | 8.8 | 26.8 | 6.9 | 4.5 | 3.6 | 6 |
718 | 743 | | | | | - | - | - | - | 22.2 | 54.6 | 27.5 | 0.7 | 6 | |
718 | 743 | | | | | - | - | - | - | 8.8 | 29.6 | 20.3 | 0.7 | 8.6 | |
Singh et al, 2013 [34] | India | 1160 | 658(3.84) | 502(1.6) | 10‑18 | - | 31(2.67) | - | 0.9 | 1.7 | 2.2 | 0.47 | 5.66 | 10.66 | 3.44 | 6.3 | 2.75 | 8 |
Sarrafzadegan et al, 2013 [35] | Iran | 1992 | 1014 | 978 | - | 90(4.5) | - | 240(12.1) | - | - | - | - | 9 | 24.9 | 10.9 | 4.6 | 22.8 | 6 |
1014(13.7) | 978(10.3) | - | | | | - | - | 7 | 5.1 | 21 | 24.9 | 42.9 | 4.6 | 22.8 | |
Qorbani et al,2013 [36] | Iran | 3565 | 1793(2.3) | 1772(2.9) | 10–18 | 91(2.6) | - | - | - | 1.2 | 1.4 | - | - | - | - | - | - | 6 |
Khashayar et al, 2013 [37] | Iran | 5738 | 2863 | 2875 | 10–18 | 144(2.5) | - | - | 1.1 | 1.4 | - | - | 16.3 | 24.9 | 6.5 | 12.1 | 5.4 | 8 |
Andrabi et al, 2013 [38] | India | 758 | 385(3.9) | 373(3.8) | 8–18 | - | 29(3.8) | - | 0.4 | 3.4 | 2 | 1.8 | 4.5 | 4.4 | 3.8 | 1.3 | - | 8 |
Xu et al, 2012 [39] | China | 8764 | 4495(0.7) | 4269(0.5) | 7–11 | 52(0.6) | - | - | 0.05 | 0.55 | 0.35 | 0.25 | 13.6 | 5.2 | 3.9 | 2.1 | 1.8 | 8 |
Nasreddine et al, 2012 [40] | Lebanon | 263 | 112 | 115 | - | 24(9.1) | 26(9.9) | - | 0.4 | 8.7 | - | - | 50.6 | 38.4 | 10.6 | 4.9 | 12.2 | 6 |
Mehrkash et al, 2012 [41] | Iran | 450 | 225(4.4) | 225(1.6) | 15–18 | - | 15(3.3) | - | 0.9 | 2.4 | 2.4 | 0.9 | 4.2 | 11.6 | 33.3 | 12.4 | 4.9 | 6 |
Chen et al, 2012 [42] | China | 3814 | - | - | 10–18 | 372(9.8) | - | - | 0.2 | 9.6 | - | - | - | - | 45 | 13 | - | 6 |
Liu e al, 2010 [43] | China | 1844 | 938(5.7) | 906(7.5) | 7–14 | - | 121(6.6) | - | 1.9 | 4.7 | 2.9 | 3.7 | 23.4 | 15.8 | 16.1 | 0.2 | 23.5 | 6 |
Khader et al, 2010 [44] | Jordan | 512 | 235 | 277 | 10–18 | 11(2.1) | - | - | - | - | - | - | 5.8 | 26.1 | 17.2 | 7.2 | 6.2 | 6 |
Hirschler et al, 2010 [45] | Argentina | 1009 | 508(5.3) | 501(6) | 6–14 | - | 57(5.8) | - | 0.4 | 5.4 | 2.8 | 3 | 27.6 | 19.7 | 12.9 | 0.8 | 8.5 | 6 |
Ella et al, 2010 [46] | Egypt | 4250 | 1806(7.4) | 2444(7.4) | 10–18 | - | 308(7.2) | - | - | - | 3.1 | 4.1 | 20 | 24 | 22 | 4 | 25.5 | 8 |
Afkhami-Ardekani et al, 2010 [47] | Iran | 932 | 402 | 530 | 10–19 | 75(8) | 63(6.7) | - | - | - | - | - | - | - | - | - | - | 5 |
Seki et al, 2009 [48] | Brazil | 2170 | 1103(4.2) | 1067(3) | 6–16 | - | 78(3.6) | - | 0.3 | 3.3 | 2.1 | 1.5 | 11.2 | 43.2 | 6.4 | 0.6 | 9.8 | 8 |
Salem et al, 2009 [49] | Iran | 1221 | - | 1221(3.9) | 11–18 | - | 48(3.9) | - | - | - | - | 3.9 | 1.2 | 44.7 | 15.8 | 7.9 | 1.5 | 8 |
Mirhosseini et al, 2009 [50] | Iran | 622 | - | 622(6.5) | 15–17 | - | 40(6.5) | - | 4.8 | 1.7 | - | 6.5 | 3.7 | 57 | 24.5 | 16.7 | 6.1 | 5 |
Matsha et al, 2009 [51] | S.Africa | 1272 | 496(8.1) | 776(5.5) | 10–16 | 24(1.9) | 83(6.5) | - | 2.2 | 4.3 | 3.1 | 3.4 | 9.9 | 48.3 | 9.3 | 4.2 | 9.3 | 5 |
496(3.4) | 776(0.9) | | | | | 0.95 | 0.95 | 1.3 | 0.6 | 10.8 | 48.3 | 4.1 | 4.2 | 6.8 | |
Li et al, 2008 [52] | China | 2761 | 1478(3.4) | 1283(4) | 15–19 | - | - | 102(3·7) | 2.2 | 1.5 | 1.8 | 1.9 | 3·8 | 53·8 | 19·6 | 0·8 | 18·2 | 6 |
Singh et al, 2007 [53] | India | 1083 | 571(3.2) | 512(5.5) | 12–17 | - | 46(4.2) | - | 1.7 | 2.5 | 1.6 | 2.6 | 4 | 25.8 | 20.4 | 5 | 7.8 | 5 |
Kelishadi et al, 2006 [54] | Iran | 4811 | 2248 | 2563 | 6–18 | - | 678(14) | - | - | - | - | - | 23 | 72 | 38 | 4 | 7 | 6 |
Esmaillzadeh et al, 2006 [55] | Iran | 3036 | 1413(10.3) | 1623(9.9) | 10–19 | - | 307(10.1) | - | 3.9 | 6.2 | 4.8 | 5.3 | 10 | 42.8 | 37.5 | 0.6 | 23.8 | 6 |
Rodríguez-Morán et al, 2004 [56] | Mexico | 965 | 499(4.6) | 466(8.6) | 10–18 | - | 63(6.5) | - | - | - | 2.4 | 4.1 | 27.7 | 20.8 | 9.5 | 7.7 | 7.1 | 6 |
Prevalence of MetS and components among overweight and obese children and adolescents
The pooled prevalence of MetS was estimated based on the three diagnostic methods (IDF, ATP III and de Ferranti). A total of 14 articles [35, 47, 55, 58, 63, 69, 72, 77, 79, 87–89, 92, 95] were eligible to compute the pooled prevalence of MetS in IDF criteria. Accordingly, 24.1% (95% CI: 16.90, 31.29, I2 = 96.6%) of the study subjects were found to have MetS. Abdominal obesity was the most common (60.9%) component of MetS, whereas high FG level was the least (10.3%) component. According to the modified ATP III, the pooled prevalence of MetS was 36.51% (95% CI: -1.76, 74.78, I2 = 99.8%). It was computed using eight articles [50, 57, 63, 71, 77, 84, 89, 104]. Twothirds (67.2%) of the children and adolescents were found to have abdominal obesity, but very few (3.4%) of them had high FG level. Besides, only two articles [89, 91] were eligible to estimate the pooled prevalence of MetS (56.32%, 95% CI: 22.34, 90.29, I2 = 94.4%) among overweight and/or obese children and adolescents in accordance with de Ferranti criteria. Similarly, abdominal obesity and high FG level were the most (91.2%) and least (7.75%) components of MetS in the de Ferranti diagnostic criteria.
The pooled prevalence of MetS was also computed based on gender. The prevalence of MetS was relatively higher in males (26.63%) than females (24.05%) in the IDF method. Likewise, males (33.37%) were highly affected by MetS than females (31.4%) according to the modified ATP III diagnostic criteria (Fig. 2 & Table 4).
Table 4
Pooled prevalence of MetS & components in overweight & Obese children and adolescents.
Variables | Characteristics | # of studies | Pooled prevalence, (95% CI) | Heterogeneity (I2(%), P-value)) | Model |
Diagnostic Criteria | IDF | 14 | 24.09 (16.90, 31.29) | 96.6, P ≤ 0.001 | REM |
ATP III | 8 | 36.51 (-1.76, 74.78) | 99.8, P ≤ 0.001 | REM |
de Ferranti | 2 | 56.32 (22.34,90.29) | 94.4, P ≤ 0.001 | REM |
Components of MetS (IDF) | Abdominal Obesity | 12 | 60.90 (46.63,75.16) | 99.7, P ≤ 0.001 | REM |
Low HDL-C | 13 | 34.83 (23.8, 46.48) | 98.0, P ≤ 0.001 | REM |
High TG | 12 | 18.59 (13.21,23.98) | 93.0, P ≤ 0.001 | REM |
High FG | 13 | 10.27 (6.67,13.87) | 95.9, P ≤ 0.001 | REM |
Elevated BP | 13 | 23.88 (17.29, 30.47) | 99.8, P ≤ 0.001 | REM |
Components of MetS (ATPIII) | Abdominal Obesity | 8 | 67.20 (49.45,84.95) | 98.9, P ≤ 0.001 | REM |
Low HDL-C | 8 | 42.48 (33.45, 51.51) | 99.8, P ≤ 0.001 | REM |
High TG | 8 | 38.85 (27.61, 50.10 | 92.9, P ≤ 0.001 | REM |
High FG | 7 | 3.39 (1.05,5.74) | 81.4, P ≤ 0.001 | REM |
Elevated BP | 8 | 29.56 (15.03, 44.8) | 96.9, P ≤ 0.001 | REM |
Components of MetS (de Ferranti) | Abdominal Obesity | 2 | 91.20 (80.42, 101.98) | 95.6, P ≤ 0.001 | REM |
Low HDL-C | 2 | 62.29 (2.91, 121.68) | 99.7, P ≤ 0.001 | REM |
High TG | 2 | 42.40 (38.39, 46.40) | 0.00, P = 0.632 | FEM |
High FG | 2 | 7.75 (-4.20, 19.71) | 97.3, P ≤ 0.001 | REM |
Elevated BP | 2 | 53.04 (8.25, 97.82) | 99.1, P ≤ 0.001 | REM |
Gender (IDF) | Male | 10 | 26.63 (23.95, 29.31) | 99.3, P ≤ 0.001 | REM |
Female | 10 | 24.05 (16.65, 31.45) | 90.7, P ≤ 0.001 | REM |
Gender (ATPIII) | Male | 5 | 33.37 (19.68, 47.06) | 99.5, P ≤ 0.001 | REM |
Female | 5 | 31.40 (15.43, 47.36) | 99.8, P ≤ 0.001 | REM |
REM: Random Effect Model; FEM: Fixed Effect Model |
Prevalence of MetS & components in the general population of children & adolescents
The pooled prevalence of MetS was estimated in LMICs using the IDF, ATP III and de Ferranti diagnostic methods. A total of 30 [33, 36–38, 40–44, 46, 48, 51, 52, 54, 60, 62, 68, 70, 73–75, 78, 80, 81, 83, 85, 90, 94, 98, 102], 33 [34, 39, 42, 43, 51, 53, 56, 59–62, 65–67, 73–76, 82, 85, 86, 93, 96–102, 105–108] and 8[42, 45, 49, 51, 64, 75, 78, 103] articles were eligible to compute the pooled estimates in the IDF, ATP III and de Ferranti diagnostic criteria, respectively. According to the IDF criteria, the pooled prevalence of MetS among the general population of children and adolescents was 3.98% (95% CI: 3.35,4.61, I2 = 97.8%). The pooled estimate in males (3.46%; 95% CI: 2.69, 4.23, I2 = 97.6%) was relatively higher than females (2.99%; 95% CI: 2.34, 3.65, I2 = 95.6%). From the components, low HDL-C level was the commonest (27.93%) and high FG (7.78%) was the infrequent one.
Similarly, 6.71% (95% CI: 5.51, 7.91, I2 = 97.6%) study subjects were found to have MetS in the ATP III criteria. MetS among males (6.24%; 95% CI: 4.89, 7.59, I2 = 93.9%) and females (6.51%; 95% CI: 4.99, 8.03, I2 = 95.8%) was nearly the same. Low HDL-C was seen in one third (31.3%; 95% CI: 23.89, 38.72, I2 = 99.7%) of study subjects and high FG in 6.1% (95% CI: 5.02, 7.15, I2 = 98.7%) of study subjects.
Besides, the pooled prevalence of MetS in children and adolescents with de Ferranti method was 8.19% (95% CI: 5.58, 10.79, I2 = 96.2%) with the same estimate in males (8.78%; 95% CI: 5.45, 12.12, I2 = 94.3%) and females (8.51%; 95% CI: 5.21, 11.75, I2 = 93.7%). The pooled estimate of low HDL-C was 45.83% (95% CI: 34.53, 57.14, I2 = 99.1%), the highest, and only 2.12% (95% CI: 1.15, 3.08, I2 = 94.7%) of the population had a high FG level (Fig. 3 & Table 5).
Table 5
The pooled prevalence of MetS and components in the general population
Variables | Characteristics | # included articles | Pooled Prevalence (95%, CI) | Heterogeneity (I2 (%), P-value) | Model |
Diagnostic Criteria | IDF | 30 | 3.98 (3.35,4.61) | 97.8, P ≤ 0.001 | REM |
ATP III | 33 | 6.71 (5.51, 7.91) | 96.7, P ≤ 0.001 | REM |
de F. | 8 | 8.19 (5.58, 10.79) | 96.2, P ≤ 0.001 | REM |
Gender distribution of MetS (IDF) | Male | 20 | 3.46 (2.69, 4.23) | 96.7, P ≤ 0.001 | REM |
Female | 20 | 2.99 (2.34, 3.65) | 95.6, P ≤ 0.001 | REM |
Gender distribution of MetS (ATPIII) | Male | 24 | 6.24 (4.89, 7.59) | 93.9, P ≤ 0.001 | REM |
Female | 26 | 6.51(4.99, 8.03) | 95.8, P ≤ 0.001 | REM |
Gender distribution of MetS (deF.) | Male | 7 | 8.78 (5.45, 12.12) | 94.3, P ≤ 0.001 | REM |
Female | 7 | 8.51 (5.21, 11.75) | 93.7, P ≤ 0.001 | REM |
Study Population (IDF) | Overweight & Obese | 11 | 1.48 (0.94, 2.01) | 87.8, P ≤ 0.001 | REM |
Others* | 12 | 0.58 (0.33, 0.82) | 93.2, P ≤ 0.001 | REM |
Study Population (ATP III) | Overweight & Obese | 18 | 4.66 (3.49, 5.83) | 95.7, P ≤ 0.001 | REM |
Others | 19 | 2.31 (1.53, 2.72) | 95.7, P ≤ 0.001 | REM |
Study Population (de F. ) | Overweight & Obese | 4 | 3.95 (1.82, 6.08) | 93.3, P ≤ 0.001 | REM |
Others* | 4 | 3.20 (0.78, 5.62) | 96.4, P ≤ 0.001 | REM |
Components MetS (IDF) | Abdominal obesity | 25 | 18.85 (16.39, 21.31) | 98.9, P ≤ 0.001 | REM |
Low HDL-C | 25 | 27.93 (21.91, 33.96) | 99.8, P ≤ 0.001 | REM |
High TG | 26 | 11.09 (9.13, 13.05) | 99.3, P ≤ 0.001 | REM |
High FG | 26 | 7.78 (6.40, 9.15) | 99.0, P ≤ 0.001 | REM |
Elevated BP | 25 | 8.76 (7.22, 10.29) | 99.1, P ≤ 0.001 | REM |
Components MetS (ATP III) | Abdominal obesity | 18 | 4.66 (3.49, 5.83) | 95.7, P ≤ 0.001 | REM |
Low HDL-C | 28 | 31.30 (23.89, 38.72) | 99.7, P ≤ 0.001 | REM |
High TG | 28 | 21.05 (16.63,25.48) | 99.4, P ≤ 0.001 | REM |
High FG | 28 | 6.08 (5.02, 7.15) | 98.7, P ≤ 0.001 | REM |
Elevated BP | 27 | 12.27 (9.39, 15.16) | 99.1, P ≤ 0.001 | REM |
Components MetS (de F.) | Abdominal obesity | 7 | 22.65 (14.01, 31.39) | 99.3, P ≤ 0.001 | REM |
Low HDL-C | 6 | 45.83 (34.53, 57.14) | 99.1 P ≤ 0.001 | REM |
High TG | 7 | 17.4 (12.24, 21.84) | 97.3 P ≤ 0.001 | REM |
High FG | 7 | 2.12 (1.15, 3.08) | 94.7, P ≤ 0.001 | REM |
Elevated BP | 7 | 12.86 (7.11, 18.61) | 98.7, P ≤ 0.001 | REM |
* others: underweight and normal weight, REM: Random Effect Model; de F. : de Ferranti |
Subgroup analysis of the pooled prevalence of MetS in the general population
The subgroup analyses were performed for the two diagnostic methods (IDF and ATP III) using the two parameters (income level and continent). In the IDF diagnostic method, the pooled estimate of MetS in LIE, LMIE and UMIE countries were estimated. The prevalence of MetS in LIEs (12.4%, 95% CI: 10.5, 14.65) was computed from one study. Likewise, the pooled estimates of MetS in LMIE (6.91%; 95% CI: 2.35, 11.46, I2 = 98.2%) and UMIE (3.51%; 2.88, 4.14, I2 = 97.7% countries were computed from three and 26 articles, respectively. Regarding the continent where the original studies were conducted, only three articles were from Africa, seven articles from Latin America and the majorities (20) articles were from Asia. The pooled prevalence of MetS in Africa, Asia and Latin America were 6.03% (95% CI: 0.24, 11.28, I2 = 94.7%), 4.39% (95% CI: 3.50, 5.29, I2 = 98%), and 2.46% (95% CI: 1.29, 3.64, I2 = 97.8%) (Fig. 4).
According to the ATP III diagnostic method, the pooled prevalence of MetS in countries classified under LMIE and UMIE was estimated from eight and 25 eligible articles, respectively. Accordingly, 5.73% (95% CI: 3.72, 7.74, I2 = 95.9%) of the study subjects in LMIEs and 7% (95% CI: 5.53, 8.48, I2 = 96.8%) in UMIE countries were found to have MetS. The pooled prevalence of MetS in Africa, Latin America and Asia was computed from two, eight and 23 articles respectively. Thus, 6.71% (95% CI: 5.51, 7.91, I2 = 0.00%) in Africa, 5.19% (95% CI: 3.31, 7.05, I2 = 95.3%) in Latin America and 7.24% (95% CI: 5.64, 8.84%, I2 = 96.9%) in Asia had MetS (Fig. 5).
Publication Bias and Sensitivity Analysis
Due to the presence of high heterogeneity among the included articles, the possible sources of variation were further explained. Thus, the funnel plots for both IDF and ATP III diagnostic criteria were presented (Fig. 6). The asymmetry of plots was objectively verified by Egger’s regression test and there was publication bias among the articles included in computing the pooled prevalence of MetS in the IDF criteria (P = 0.001), whereas the Egger’s regression test revealed that there was no publication bias in the pooled estimate of ATP III diagnostic criteria (P = 0.063). Moreover, sensitivity analysis was computed for both diagnostic methods. This was done to evaluate if the pooled estimates were altered by the exclusion of any single study. However, none of the studies had significant effects in the pooled estimates (Fig. 7).
Finally, the prevalence of MetS in LMICs among the general population children and adolescents was plotted in linear graph using the number of cases with publication year (2004 to 2020). The graph depicted that there is an increasing trend in the two diagnostic methods (IDF & de Ferranti) and the reverse was true in ATP III criteria (Fig. 8).