Maternal serum level of resistin is associated with risk for gestational diabetes mellitus: A meta-analysis

Table 1 Detailed characteristics of all eligible studies for the association between serum resistin levels and gestational diabetes mellitus

Ref.	Location	Study design	Number GDM/C	GDM diagnosis	Time for sampling	Assay method	Need for insulin n (%)	Resistin level, ng/mL mean ± SD
								GDM	Control	P
Tsiotra et al[49], 2018	Greece	CC	15/23	75 g ADA	39 wk	LUMINEX xMAP	4 (26.7)	26.147 ± 7.337	23.440 ± 1.567	NS
Lobo et al[42], 2018	Brazil	CC	15/30	75 g IADPSG	< 14 wk	ELISA	0	14.047 ± 5.334	12.357 ± 4.747	NS
			18/28		14-20 wk		0	14.420 ± 6.157	14.219 ± 5.721	NS
Siddiqui et al[25], 2018	Saudi Arabia	CC	14/21	100 g ADA	24-32 wk	Randox evidence biochip analyzer	NI	9.1 ± 4.2	6.1 ± 1.6	0.02
Bagci et al[21], 2018	Turkey	CC	40/40	100 g NDDG	24-28 wk	ELISA	NI	16.78 ± 6.83	12.79 ± 5.02	0.004
Khanam et al[37], 2017	Australia	Cohort	52/71	75 g ADIPS	14 wk	Multiplex assay kits	0	0.667 ± 0.515	0.697 ± 0.249	NS
			52/71		18 wk		0	0.896 ± 0.547	0.806 ± 0.416	NS
Ravnsborg et al[45], 2016	Denmark	CC	199/208	75 g 2 h ≥ 9.0 mmol/L	8+1-13+6 wk	ELISA	78 (39.2)	14.06 ± 6.43	13.22 ± 4.87	NS
Huang et al[13], 2016	China	CC	43/24	75 g IADPSG	37-40 wk	ELISA	17 (39.5)	19240 ± 5860	14570 ± 4890	< 0.05
Takhshid and Zare[48], 2015	Iran	CC	75/70	100 g Carpenter and Coustan	30 wk	ELISA	NI	13.0 ± 6.6	11.4 ± 6.9	NS
Boyadzhieva et al[32], 2013	Bulgaria	CC	127/109	75 g IADPSG	24-28 wk	BioVendor® kits	0	10.11 ± 2.2	9.09 ± 3.2	NS
Nanda et al[43], 2012	UK	CC	60/240	75 g fasting ≥ 6.0 mmol/L or 2 h ≥ 7.8 mmol/L	11-13 wk	ELISA	0	8.32 ± 4.58	8.28 ± 3.38	NS
Skvarca et al[47], 2012	Slovenia	CS	30/25	100 g Carpenter and Coustan	Approximately 27 wk	ELISA	0	2.00 ± 0.68	2.40 ± 1.26	NS
Akdeniz et al[31], 2011	Turkey	CC	20/22	ADA	Before delivery	ELISA	20 (100)	8.7 ± 2.1	8.1 ± 2.5	NS
Vitoratos et al[18], 2011	Greece	Cohort	30/30	100 g Carpenter and Coustan	26-28 wk	Sandwich immunoassay kit	0	0.21 ± 0.08	0.19 ± 0.12	NS
			30/30		38 wk		0	0.28 ± 0.2	0.21 ± 0.13	0.02
			30/30		The third postpartum day		0	0.25 ± 0.11	0.19 ± 0.10	0.03
Kleiblova et al[38], 2010	Czech Republic	CC	10/13	75 g Czech Diabetes Association	At delivery	ELISA	10 (100)	12.6 ± 4.2	10.9 ± 2.1	NS
Vitoratos et al[50], 2010	Greece	CC	30/30	100 g Carpenter and Coustan	24-26 wk	Sandwich immunoassay kit	0	0.1913 ± 0.1096	0.21 ± 0.0822	NS
Kralisch et al[39], 2009	Germany	CC	40/80	75 g ADA	G: 29 ± 3 wk; C: 28 ± 4 wk	ELISA	NI	6.5 ± 2.7	7.4 ± 3.3	NS
Kuzmicki et al[14], 2009	Poland	CC	81/82	75 g WHO	24-31 wk	Quantikine immunoassay kit	0	21.9 ± 5.9	19.0 ± 5.9	< 0.001
Palik et al[17], 2007	Hungary	CS	30/15	75 g WHO	26-30 wk	ELISA	30 (100)	15.76 ± 3.52	13.0 ± 3.60	< 0.001

CC: Case-control study; CS: Cross-sectional study; ADA: American Diabetes Association; IADPSG: International Association of Diabetic Pregnancy Study Group; WHO: World Health Organization; NDDG: National Diabetes Data Group; ADIPS: Australasian Diabetes in Pregnancy Society; RIA: Radio Immunoassay; NI: No information; NS: Non-significant.

Table 2 Quality assessment of the included studies based on scores of Newcastle-Ottawa Scale (case-control study version and cohort version)

Ref.	Case definition adequacy	Representativeness of cases	Selection of controls	Definition of controls	Comparability of cases and controls	Ascertainment of exposure	Same method of ascertainment for cases and controls	Non-response rate	Total quality score
Tsiotra et al[49], 2018	1	0	0	1	1	1	1	NI	5
Lobo et al[42], 2018	1	1	1	1	2	1	1	1	9
Siddiqui et al[25], 2018	1	0	0	1	1	1	1	NI	5
Bagci et al[21], 2018	1	0	0	1	1	1	1	NI	5
Ravnsborg et al[45], 2016	1	1	1	1	2	1	1	1	9
Huang et al[13], 2016	1	0	0	1	2	1	1	NI	6
Takhshid and Zare[48], 2015	1	0	0	1	2	1	1	NI	6
Boyadzhieva et al[32], 2013	1	1	1	1	1	1	1	NI	7
Nanda et al[43], 2012	1	1	0	1	1	1	1	NI	6
Skvarca et al[47], 2012	1	0	0	1	2	1	1	NI	6
Akdeniz et al[31], 2011	1	0	0	1	1	1	1	NI	5
Kleiblova et al[38], 2010	1	0	0	1	1	1	1	NI	5
Vitoratos et al[50], 2010	1	0	0	1	2	1	1	NI	6
Kralisch et al[39], 2009	1	0	0	1	2	1	1	NI	6
Kuzmicki et al[14], 2009	1	0	0	1	2	1	1	NI	6
Palik et al[17], 2007	1	0	0	1	1	1	1	NI	5
Ref.	Representativeness of the exposed cohort	Selection of the non-exposed cohort	Ascertainment of exposure	Demonstration that outcome of interest was not present at start of study	Comparability of cohorts	Assessment of outcome	Follow-up long enough for outcomes to occur	Adequacy of follow -up of cohorts	Total quality score
Khanam et al[37], 2017	0	1	1	1	2	1	1	0	7
Vitoratos et al[18], 2011	0	1	1	1	2	1	1	1	8

NI: No information.

Table 3 Summary of different comparative results of serum resistin level with gestational diabetes mellitus risk

Category		No. of comparisons	No. of cases	No. of controls	SMD (95%CI)	Z	P	I2%	Phet
Overall		22	1041	1292	0.250 (0.116, 0.384)	3.65	0.000	53.1	0.002
Gestational age at blood sampling	Before 14 wk	4	326	549	0.087 (-0.055, 0.230)	1.20	0.229	0.0	0.550
	14-28 wk	8	408	415	0.217 (-0.003, 0.436)	1.93	0.053	55.5	0.028
	After 28 wk	9	277	298	0.394 (0.108, 0.680)	2.70	0.007	60.5	0.009
	Postpartum	1	30	30	0.571 (0.054, 1.087)	-	-	-	-
Need for insulin	No need for insulin	12	555	776	0.177 (0.018, 0.336)	2.18	0.029	43.7	0.052
	Need for insulin	6	317	305	0.403 (0.119, 0.687)	2.78	0.005	44.9	0.106
	No information	4	169	211	0.356 (-0.143, 0.855)	1.40	0.162	80.6	0.001

P_het: P value for heterogeneity; OR: Odds ratio; CI: Confidence interval; SMD: Standardized mean difference.

Table 4 Meta-regression analysis results

Covariate	Coefficient	Std. error	t	P	95%CI lower	95%CI upper
No need for insulin	-0.482	0.183	-2.64	0.017	-0.868	-0.097
Need for insulin	-0.169	0.190	-0.89	0.388	-0.570	0.233
Age distribution similar	0.298	0.126	2.37	0.030	0.033	0.563
ELISA	-0.399	0.160	-2.50	0.023	-0.737	-0.062