BACKGROUND@#
Gestational diabetes mellitus (GDM) is a common complication during
pregnancy .
Obesity and
overweight are closely related to
metabolic diseases and diabetes. However, the
role of
adipose tissue in the pathogenesis of GDM remains to be studied. The aim of this study was to investigate the correlation of
vitamin D (VD) levels, VD receptor (VDR), and
peroxisome proliferator-activated receptor γ (
PPAR γ) expression with GDM in
overweight or obese
women .@*
METHODS @#One hundred and forty
pregnant women with full-term single-
birth cesarean-section were selected as the study subjects and grouped (70 GDM
women , including 35 non-
overweight /non-obese
women [group G1] and 35
women with
overweight or
obesity [group G2]; 70
pregnant women with normal
glucose tolerance, including 35 non-
overweight /non-obese
women [group N1] and 35
overweight /obese
women [group N2]). The levels of
serum VD,
blood biochemistry , and
adiponectin were compared in these
women .
Subcutaneous adipose tissue was isolated from the
abdominal wall incision. VDR and
PPAR γ
messenger RNA (
mRNA ) transcript levels in these adipose
tissues were quantified by
real-time polymerase chain reaction . The differences between the levels of
PPAR γ
protein and phosphorylated
PPAR γ Ser273 were detected by
Western blotting .@*RESULTS@#The
serum VD level of GDM
women was lower in comparison to that of
women with normal
glucose tolerance (G1 vs. N1 20.62 ± 7.87 ng/mL vs. 25.85 ± 7.29 ng/mL, G2 vs. N2 17.06 ± 6.74 ng/mL vs. 21.62 ± 7.18 ng/mL, P < 0.05), and the lowest in
overweight /obese GDM
women . VDR and
PPAR γ
mRNA expression was higher in the adipose
tissues of GDM
women in comparison to that of
women with normal
glucose tolerance (VDR
mRNA G1 vs. N1 210.00 [90.58-311.46] vs. 89.34 [63.74-159.92], G2 vs. N2 298.67 [170.84-451.25] vs. 198.28 [119.46-261.23],
PPAR γ
mRNA G1 vs. N1 100.72 [88.61-123.87] vs. 87.52 [66.37-100.04], G2 vs. N2 117.33 [100.08-149.00] vs. 89.90 [76.95-109.09], P < 0.05), and their expression was the highest in GDM +
overweight /obese
women . VDR
mRNA levels positively correlated with the pre-
pregnancy body mass index (BMI), pre-delivery BMI,
fasting blood glucose (FBG),
homeostasis model assessment of
insulin resistance (HOMA-IR), and
PPAR γ
mRNA while it negatively correlated with the VD and the
adiponectin levels (r = 0.395, 0.336, 0.240, 0.190, 0.235, -0.350, -0.294, respectively, P < 0.05). The degree of
PPAR γ Ser273
phosphorylation increased in obese and GDM
pregnant women .
PPAR γ
mRNA levels positively correlated with pre-
pregnancy BMI, pre-delivery BMI, FBG, HOMA-IR,
serum total
cholesterol ,
triglyceride ,
free fatty acid , and VDR
mRNA , while it negatively correlated with the VD and
adiponectin levels (r = 0.276, 0.199, 0.210, 0.230, 0.182, 0.214, 0.270, 0.235, -0.232, -0.199, respectively, P < 0.05).@*CONCLUSIONS@#Both GDM and
overweight /obese
women had decreased
serum VD levels and up-regulated VDR and
PPAR γ
mRNA expression in
adipose tissue , which was further higher in the
overweight or obese
women with GDM. VD may regulate the formation and differentiation of
adipocytes through the VDR and
PPAR γ pathways and participate in the occurrence of GDM.