Metabolic Characteristics of Gestational Diabetes Mellitus and the Effects on Pregnancy Outcomes

Figures & data

Table 1 Baseline Characteristics of the Study Population

Variables	NGT Group (n=191)	GDM Group (n=192)	p
Age (year)	29.62±3.79	29.91±4.12	0.484
Height (cm)	160.49±5.08	160.20±4.63	0.561
Prepregnancy weight (kg)	58.47±9.61	58.55±9.77	0.937
Prepregnancy BMI (kg/m^2)	22.68±3.47	22.79±3.57	0.748
Systolic blood pressure (mmHg)	109.97±9.81	112.80±10.98	0.008
Diastolic blood pressure (mmHg)	71.39±8.07	71.51±9.19	0.894
Gestational age at enrollment (week)	11.98±4.10	11.53±3.13	0.237
Occupation			0.165
Staff of administrative, enterprise or institution	121(63.3%)	112(58.3%)
Freelancer	37(19.4%)	37(19.3%)
Other practitioner	4(2.1%)	11(5.7%)
Not stated	29(15.2%)	32(16.7%)
Education			0.426
Primary school	1(0.5%)	1(0.5%)
Junior middle school	13(6.8%)	17(8.9%)
High school or technical school	115(60.2%)	116(60.4%)
College or above	36(18.8%)	24(12.5%)
Not stated	26(13.6%)	34(17.7%)
Permanent address			1.000
Local household registration	188(98.4%)	189(98.4%)
Non-local household registration	3(1.6%)	3(1.6%)
The nature of household registration			0.373
Agriculture	178(93.2%)	183(95.3%)
Non-agricultural	13(6.8%)	9(4.7%)
Gravidity			0.682
1	67(35.1%)	71(37.0%)
2–4	110(57.6%)	108(56.3%)
≥5	14(7.3%)	13(6.8%)
Parity			0.110
0	92(48.2%)	109(56.8%)
1	92(48.2%)	76(39.6%)
≥2	7(3.7%)	7(3.6%)

Notes: The p values were calculated using Two-sample t-test, Chi-square test or Mann–Whitney U-test according to the type of variables. Variables with statistical significance are shown in boldface.

Abbreviations: GDM, gestational diabetes mellitus; NGT, normal glucose tolerance; BMI, body mass index.

Figure 1 Metabolic characteristics of the NGT and GDM groups. (A) Glucose parameters; (B) Insulin parameters; (C) Insulin parameters adjusted by glucose; (D) Parameters of area under the curve; (E) Parameters for assessing insulin resistance and β cell function. ^†Variable was log-transformed before statistical analysis and is shown as median. *p<0.05; **p<0.01; ***p<0.001.

Abbreviations: GDM, gestational diabetes mellitus; NGT, normal glucose tolerance; FPG, fasting plasma glucose; 1hPG, 1-hour plasma glucose; 2hPG, 2-hour plasma glucose; FINS, fasting insulin; 1hINS, 1-hour insulin: 2hINS, 2-hour insulin; INS, insulin; GLU, glucose; AUC, area under the curve; HOMA-IR, homeostasis model assessment of insulin resistance; HOMA-β, homeostasis model assessment of beta cell function; ISI_Matsuda, Matsuda insulin sensitivity index; IGI₆₀, insulinogenic index at 60 min; DI, disposition index.

Figure 2 Prevalence of GDM subtypes in the GDM group.

Abbreviations: GDM, gestational diabetes mellitus; IFG, impaired fasting glucose; IGT, impaired glucose tolerance; IFSG, impaired fasting and stimulated glucose.

Figure 3 Metabolic characteristics of GDM subgroups. (A) Glucose parameters; (B) Insulin parameters; (C) Insulin parameters adjusted by glucose; (D) Parameters of area under the curve; (E) Parameters for assessing insulin resistance and β cell function. ^†Variables were log-transformed before statistical analysis and are shown as the median. *p<0.05; **p<0.01; ***p<0.001.

Abbreviations: GDM, gestational diabetes mellitus; NGT, normal glucose tolerance; IFG, impaired fasting glucose; IGT, impaired glucose tolerance; IFSG, impaired fasting and stimulated glucose; FPG, fasting plasma glucose; 1hPG, 1 hour plasma glucose; 2hPG, 2 hour plasma glucose; FINS, fasting insulin; 1hINS, 1 hour insulin: 2hINS, 2 hour insulin; INS, insulin; GLU, glucose; AUC, area under the curve; HOMA-IR, homeostasis model assessment of insulin resistance; HOMA-β, homeostasis model assessment of beta cell function; ISI_Matsuda, Matsuda insulin sensitivity index; IGI₆₀, insulinogenic index at 60 min; DI, 75 g OGTT-derived disposition index.

Table 2 Delivery Outcomes of Participants

Variables	NGT Group (n=191)	GDM Group (n=192)	p
Gestational age at delivery (week)	38.55±1.50	38.42±1.20	0.356
Preterm delivery			0.144
No	175(91.6%)	183(95.3%)
Yes	16(8.4%)	9(4.7%)
Birth weight of the newborns (g)	3255±439	3316±428	0.170
Macrosomia			0.151
No	185(96.9%)	180(93.8%)
Yes	6(3.1%)	12(6.3%)
Length of the baby (cm)	50.08±1.78	50.26±1.39	0.272
Delivery mode			0.149
Natural childbirth	71(37.2%)	58(30.2%)
Cesarean section	120(62.8%)	134(69.8%)
Episiotomy during vaginal delivery			0.326
No	70(98.6%)	55(94.8%)
Yes	1(1.4%)	3(5.2%)
Postpartum hemorrhage			0.499
No	190(99.5%)	192(100%)
Yes	1(0.5%)	0(0)
Infant health			0.857
Poor	0(0)	1(0.5%)
Average	22(11.5%)	20(10.4%)
Good	169(88.5%)	171(89.1%)
Birth defects			0.248
No	191(100%)	189(98.4%)
Yes	0(0)	3(1.6%)

Notes: The p values were calculated using Two-sample t-test, Chi-square test or Mann–Whitney U-test according to the type of variables.

Abbreviations: GDM, gestational diabetes mellitus; NGT, normal glucose tolerance.

Figure 4 Stepwise linear regression analyses of glucose metabolism parameters and pregnancy outcomes (A): birth weight of infants. Independent variables included in the analysis were age, height, weight, prepregnancy BMI, systolic blood pressure, diastolic blood pressure, delivery gestational age and all glucose metabolism parameters of pregnant women; (B): delivery gestational age. Independent variables included in the analysis were age, weight, height, prepregnancy BMI, systolic blood pressure, diastolic blood pressure and all glucose metabolism parameters.

Abbreviations: FPG, fasting plasma glucose; 1hPG, 1 hour plasma glucose; FINS/FPG, the ratio of fasting insulin to fasting plasma glucose; BMI, body mass index.

Figure 5 Risk factors for adverse perinatal outcomes in glucose metabolism parameters. (A) Odds ratios for premature delivery risk. ^★OR was adjusted for prepregnancy BMI, systolic blood pressure and diastolic blood pressure; (B) Odds ratios for cesarean section risk. ^★OR was adjusted for age, prepregnancy BMI, systolic blood pressure and diastolic blood pressure; (C) Odds ratios for macrosomia risk. ^★OR was adjusted for prepregnancy BMI.

Abbreviations: OR, odds ratio; CI, confidence interval; DI, 75 g OGTT-derived disposition index; IGI₆₀, insulinogenic index at 60 min; AUC-INS, area under the insulin curve; ISI_Matsuda, Matsuda insulin sensitivity index; BMI, body mass index; GDM, gestational diabetes mellitus; IFG, impaired fasting glucose; FPG, fasting plasma glucose; HOMA-β, homeostasis model assessment of beta cell function; AUC-INS/AUC-GLU, ratio of total area under the insulin curve to area under the glucose curve; AUC-GLU, area under the glucose curve; FINS/FPG, the ratio of fasting insulin to fasting plasma glucose; IFSG, impaired fasting and stimulated glucose.