Fig. 1Prevalence of postpartum glucose intolerance in women with gestational diabetes mellitus according to the status of serum 25-hydroxyvitamin D level. aP<0.05.
Table 1Baseline Characteristics of Women with Gestational Diabetes Mellitus According to Serum 25(OH)D Level at Mid-Pregnancy
Characteristic |
Total |
Serum 25(OH)D <20 ng/dL |
Serum 25(OH)D ≥20 ng/dL |
P value |
Number |
348 (100.0) |
267 (76.7) |
81 (23.3) |
|
Age, yr |
33.1±3.5 |
33.1±3.6 |
33.2±3.0 |
0.870 |
Pre-pregnancy BMI, kg/m2
|
22.3±3.5 |
22.7±3.6 |
21.0±2.6 |
<0.001 |
Pre-pregnancy weight, kg |
58.0±10.1 |
58.8±10.4 |
55.2±8.7 |
0.005 |
Mid-pregnancy weight, kg |
64.9±10.1 |
66.0±10.2 |
61.3±8.9 |
<0.001 |
Weight gain, kg |
6.9±3.9 |
7.2±4.0 |
6.1±3.3 |
0.028 |
History of GDM |
10 (2.9) |
9 (3.4) |
1 (1.2) |
0.464 |
Family history of diabetes |
122 (35.1) |
88 (33.0) |
34 (42.0) |
0.145 |
Parity (% primiparous) |
203 (58.3) |
154 (57.7) |
49 (60.5) |
0.700 |
Gestational weeks |
27.8±1.7 |
27.8±1.8 |
27.8±1.4 |
0.994 |
Season |
|
|
|
0.139 |
Spring |
90 (25.9) |
66 (24.7) |
24 (29.6) |
Summer |
96 (27.6) |
71 (26.6) |
25 (30.9) |
Autumn |
97 (27.9) |
73 (27.3) |
24 (29.6) |
Winter |
65 (18.7) |
57 (21.3) |
8 (9.9) |
Systolic blood pressure, mm Hg |
112.3±13.9 |
113.5±14.1 |
108.4±12.6 |
0.002 |
Diastolic blood pressure, mm Hg |
67.9±9.9 |
68.8±10.2 |
65.1±8.5 |
0.001 |
FPG, mg/dL |
88.8±10.4 |
89.0±9.9 |
88.2±11.9 |
0.558 |
HbA1c, % |
5.2±0.4 |
5.3±0.4 |
5.1±0.3 |
0.001 |
Total cholesterol, mg/dL |
246.1±41.2 |
246.8±42.9 |
243.9±35.3 |
0.581 |
Triglyceride, mg/dL |
201.0±84.0 |
206.7±89.1 |
182.0±61.2 |
0.020 |
HDL-C, mg/dL |
72.6±12.6 |
72.7±12.8 |
72.5±12.1 |
0.910 |
Albumin, mg/dL |
3.79±0.23 |
3.78±0.24 |
3.80±0.22 |
0.436 |
Fasting C-peptide, ng/mL |
1.67±0.76 |
1.70±0.74 |
1.54±0.81 |
0.102 |
Fasting insulin, μU/mL |
6.67±4.33 |
6.95±4.37 |
5.75±4.12 |
0.029 |
HOMA-IR |
1.52±1.12 |
1.57±1.10 |
1.32±1.17 |
0.080 |
HOMA-β |
98.3±62.3 |
102.8±67.2 |
83.5±38.8 |
0.001 |
Plasma glucose at 50-g OGTT, mg/dL |
170.9±22.2 |
170.8±22.5 |
171.3±21.5 |
0.856 |
100-g OGTT |
|
|
|
|
0 min plasma glucose, mg/dL |
96.7±12.2 |
96.4±11.9 |
97.4±13.2 |
0.545 |
60 min plasma glucose, mg/dL |
193.5±28.2 |
192.4±28.4 |
196.9±28.4 |
0.204 |
120 min plasma glucose, mg/dL |
174.0±25.1 |
173.1±25.0 |
176.7±25.4 |
0.258 |
180 min plasma glucose, mg/dL |
144.5±27.6 |
145.2±26.5 |
141.9±30.9 |
0.338 |
Serum 25(OH)D |
14.3±8.2 |
10.8±4.9 |
26.0±5.2 |
<0.001 |
Table 2Pregnancy Outcomes of Women with Gestational Diabetes Mellitus According to Serum 25(OH)D Level
Variable |
Serum 25(OH)D <20 ng/dL (n = 267) |
Serum 25(OH)D ≥20 ng/dL (n = 81) |
P value |
Gestational age at delivery, wk |
38.3±1.7 |
38.5±2.2 |
0.543 |
Preterm deliverya
|
38 (14.5) |
11 (14.1) |
1.000 |
Cesarean sectionb
|
116 (48.7) |
33 (45.8) |
0.688 |
Treatment of GDM |
|
|
0.211 |
Diet and exercise only |
221 (82.8) |
73 (90.1) |
Insulin |
40 (15.0) |
6 (7.4) |
Metformin |
6 (2.2) |
2 (2.5) |
Neonate weight, g |
3097.7±508.6 |
3121.4±421.6 |
0.708 |
Table 3Clinical Characteristics of Women with Gestational Diabetes Mellitus According to Serum 25(OH)D Level at Postpartum 6 to 12 Weeks
Characteristic |
Serum 25(OH)D <20 ng/dL (n = 267) |
Serum 25(OH)D ≥20 ng/dL (n = 81) |
P value |
75-g OGTT |
|
|
|
0 min plasma glucose, mg/dL |
96.3±9.4 |
93.7±9.0 |
0.024 |
30 min plasma glucose, mg/dL |
155.4±24.6 |
145.7±27.7 |
0.016 |
60 min plasma glucose, mg/dL |
161.4±37.5 |
152.8±34.3 |
0.142 |
90 min plasma glucose, mg/dL |
150.4±40.7 |
144.1±34.7 |
0.314 |
120 min plasma glucose, mg/dL |
133.3±33.4 |
126.2±30.7 |
0.090 |
HbA1c, % |
5.5±0.3 |
5.4±0.3 |
0.100 |
Fasting C-peptide, ng/mL |
1.51±0.65 |
1.39±0.70 |
0.145 |
Fasting insulin, μU/mL |
5.38±5.22 |
5.31±9.46 |
0.929 |
HOMA-IR |
1.32±1.34 |
1.31±2.81 |
0.976 |
HOMA-β |
57.2±49.3 |
84.2±261.3 |
0.360 |
Table 4Correlations between Serum 25-Hydroxyvitamin D Levels and Glycemic Parameters
Variable |
Unadjusted |
Adjusted |
r
|
P value |
r
|
P value |
Antepartum period |
|
|
|
|
Plasma glucose at 50-g OGTT, mg/dL |
−0.031 |
0.571 |
−0.032 |
0.564 |
100-g OGTT |
|
|
|
|
0 min plasma glucose, mg/dL |
−0.011 |
0.831 |
0.008 |
0.891 |
60 min plasma glucose, mg/dL |
0.046 |
0.393 |
0.011 |
0.838 |
120 min plasma glucose, mg/dL |
0.031 |
0.565 |
−0.140 |
0.011 |
180 min plasma glucose, mg/dL |
−0.058 |
0.280 |
−0.186 |
0.001 |
HbA1c, % |
−0.266 |
< 0.001 |
−0.186 |
0.001 |
Fasting C-peptide, ng/mL |
−0.084 |
0.117 |
0.019 |
0.725 |
Fasting insulin, μU/mL |
−0.111 |
0.039 |
0.010 |
0.849 |
HOMA-IR |
−0.092 |
0.088 |
0.017 |
0.751 |
HOMA-β |
− 0.113 |
0.035 |
0.041 |
0.461 |
Postpartum period |
|
|
|
|
75-g OGTT |
|
|
|
|
0 min plasma glucose, mg/dL |
−0.151 |
0.005 |
−0.158 |
0.015 |
30 min plasma glucose, mg/dL |
−0.168 |
0.009 |
−0.174 |
0.007 |
60 min plasma glucose, mg/dL |
−0.116 |
0.071 |
−0.091 |
0.165 |
90 min plasma glucose, mg/dL |
−0.119 |
0.063 |
−0.103 |
0.114 |
120 min plasma glucose, mg/dL |
−0.129 |
0.016 |
−0.147 |
0.024 |
HbA1c, % |
−0.129 |
0.017 |
−0.129 |
0.047 |
Fasting C-peptide, ng/mL |
−0.112 |
0.037 |
−0.027 |
0.676 |
Fasting insulin, μU/mL |
−0.004 |
0.936 |
−0.049 |
0.45 |
HOMA-IR |
−0.004 |
0.943 |
−0.075 |
0.248 |
HOMA-β |
0.081 |
0.134 |
0.138 |
0.035 |
Table 5OR for Postpartum Glucose Intolerance According to Serum 25(OH)D Level in Pregnancy
Vitamin D status |
Unadjusted OR (95% CI) |
P value |
Adjusted OR (95% CI) |
P value |
Serum 25(OH)D ≥20 ng/dL |
Reference |
|
Reference |
|
Serum 25(OH)D <20 ng/dL |
2.01 (1.19–3.39) |
0.009 |
2.00 (1.13–3.55) |
0.018 |