Justyna Pliszka

Serum irisin concentration in women with gestational diabetes

Abstract Irisin is a novel myokine and adipokine which induces an increase in total body energy expenditure, improving insulin sensitivity and glucose tolerance in experimental animals. In the present study, serum irisin concentration was measured by an enzyme immunoassay in 130 women with gestational diabetes mellitus (GDM) and 140 BMI-matched patients with normal glucose tolerance (NGT). Median irisin level was significantly lower in the patients with GDM than in the NGT subjects (1703.3 [1354.8–2097.9 ng/ml] versus 1873.8 [1519.8–2294.8 ng/ml], p = 0.01); however, 3 months after childbirth its concentrations did not differ markedly between the two groups (1165.9 [872.1–1497.5] ng/ml versus 1139.0 [984.0–1376.7] ng/ml). In the whole group, irisin concentration correlated negatively with 2 h glucose level (R = −0.14, p = 0.03). In the women with NGT, irisin concentration correlated positively with ISOGTT (R = 0.22, p = 0.04) and the disposition index (DI120) (R = 0.24, p = 0.03), as well as negatively with 2 h insulin level (R = −0.23, p = 0.03) and HOMA-IR (R = −0.24, p = 0.02). Multiple regression analysis revealed that 2 h glucose and DI120 were the only variables significantly influencing serum irisin (β = 0.158, p = 0.03 and β = 0.159, p = 0.02, respectively). Our results suggest that serum irisin concentration increases markedly in pregnant women, but this increase seems to be significantly lower in patients with GDM. Chinese abstract 鸢尾素是一种新发现的肌细胞因子和脂肪因子，在动物实验中，可以提高全身能量消耗，提高胰岛素敏感性和糖耐量。本研究通过酶免测定法测定了130名妊娠糖尿病(GDM)妇女和140名BMI值相匹配的糖耐量正常(NGT)妇女血清鸢尾素浓度。GDM患者中位血清鸢尾素浓度较NGT妇女明显降低(1703.3 [1354.8–2097.9 ng/ml] 比1873.8 [1519.8–2294.8 ng/ml], p=0.01)；而在分娩三个月后两组妇女血清鸢尾素浓度并无明显差异(1165.9 [872.1–1497.5] ng/ml 比 1139.0 [984.0–1376.7]ng/ml)。所有受试对象的血清鸢尾素浓度均与餐后2h 血糖呈负相关(R=－0.14, p=0.03)。NGT妇女血清鸢尾素浓度与处置指数（DI120）(R=0.24, p=0.03)和ISOGTT(R=0.22, p=0.04)正相关，与2h胰岛素水平(R=－0.23, p=0.03)和HOMA-IR (R=﹣0.24, p=0.02)负相关。多元回归分析显示只有餐后2h血糖与DI120是显著影响血清鸢尾素浓度的变量(分别为β=0.158, p=0.03 和β=0.159, p=0.02)。研究结果显示妊娠妇女血清鸢尾素浓度明显增高，而在GDM妇女这种升高值则明显降低。

Increased Maternal and Cord Blood Betatrophin in Gestational Diabetes.

Aim The aim of the study was to compare maternal and cord blood levels of betatrophin – a new peptide potentially controlling beta cell growth - as well as in its mRNA expression in subcutaneous adipose tissue, visceral adipose tissue and placental tissue obtained from pregnant women with normal glucose tolerance (NGT) and gestational diabetes (GDM). Methods Serum betatrophin and irisin concentrations were measured by ELISA in 93 patients with GDM and 97 women with NGT between 24 and 28 week of gestation. Additionally, maternal and cord blood betatrophin and irisin, as well as their genes (C19orf80 and Fndc5) expression were evaluated in 20 patients with GDM and 20 women with NGT at term. Results In both groups, serum betatrophin concentrations were significantly higher in the patients with GDM than in the controls (1.91 [1.40-2.60] ng/ml vs 1.63 [1.21-2.22] ng/ml, p=0.03 and 3.45 [2.77-6.53] ng/ml vs 2.78 [2.16-3.65] ng/ml, p=0.03, respectively). Cord blood betatrophin levels were also higher in the GDM than in the NGT group (20.43 [12.97-28.80] ng/ml vs 15.06 [10.11-21.36] ng/ml, p=0.03). In both groups betatrophin concentrations in arterial cord blood were significantly higher than in maternal serum (p=0.0001). Serum irisin levels were significantly lower in the patients with GDM (1679 [1308-2171] ng/ml) than in the healthy women between 24 and 28 week of pregnancy (1880 [1519-2312] ng/ml, p=0.03). Both C19orf80 and Fndc5 mRNA expression in fat and placental tissue did not differ significantly between the groups studied. Conclusions Our results suggest that an increase in maternal and cord blood betatrophin might be a compensatory mechanism for enhanced insulin demand in GDM.

The expression of genes involved in NF-κB activation in peripheral blood mononuclear cells of patients with gestational diabetes

OBJECTIVE In patients with obesity and type 2 diabetes, the changes in insulin resistance are associated with the changes in expression of genes involved in nuclear factor-κB (NF-κB) activation in peripheral blood mononuclear cells (PBMCs). As such studies have never been carried out in patients with gestational diabetes (GDM), in this study, we evaluated the expression of genes involved in NF-κB activation and related to glucose metabolism in PBMCs obtained from pregnant women with GDM and normal glucose tolerance (NGT). DESIGN AND METHODS RT-PCR was performed in 60 pregnant women divided into three groups: GDM at the 1st visit, i.e. in the 24th-28th weeks of gestation (GDM1), NGT at the first visit and GDM in the 29th-32nd weeks (GDM2), and NGT at both visits. The tests were repeated 3 months postpartum. RESULTS The GDM1 group had significantly higher TLR2 (P=0.024), TLR4 (P=0.037), STAT1 (P=0.027), and CX3CL1 (P=0.017) mRNA expression, whereas the GDM2 group showed markedly lower TNFRSF1A (P=0.042), PPARG (P=0.018), STAT3 (P=0.013), and CX3CL1 (P=0.038) mRNA expression in comparison with the NGT group. The women with NGT at the 1st visit who later developed GDM had significantly higher fasting glucose (P=0.01), HOMA-IR (P=0.004), and TLR2 mRNA expression (P=0.04), as well as lower ISSI2 (P=0.01) and disposition indices, DI₃₀ (P=0.03) and DI₁₂₀ (P=0.01), than had the women who remained normoglycemic. CONCLUSIONS Our results suggest that elevated TLR2 expression, as well as higher fasting glucose and lower compensation for increased insulin resistance, may represent early metabolic disturbances in the development of GDM.

The expression of suppressor of cytokine signaling 1 and 3 in fat and placental tissue from women with gestational diabetes

The suppressor of cytokine signaling (SOCS) proteins are feedback inhibitors of signaling pathways induced by cytokines, hormones and growth factors. In the present study we measured the expression of SOCS1, SOCS3, interleukin-6 (IL-6), IL-6 receptor, IL-8 and leptin mRNA in paired samples of subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT) and placental tissue obtained from 18 pregnant women with normal glucose tolerance (NGT) and 20 subjects with gestational diabetes mellitus (GDM), using quantitative RT-PCR. The patients with GDM had significantly higher IL-8 mRNA expression in VAT than the women with NGT (p = 0.007), whereas the expression of SOCS1, SOCS3 and other genes study did not differ significantly between the two groups. Stepwise regression analysis revealed that SOCS1 mRNA expression in VAT was significantly associated with prepregnancy BMI (β = −0.68, p = 0.03) and IL-8 mRNA expression (β = 0.66, p = 0.03), whereas SOCS3 mRNA expression in VAT was independently predicted by IL-6 mRNA expression (β = 0.94, p = 0.0002, R2 = 0.88). In conclusion, our results did not show significant differences in SOCS1 and SOCS3 mRNA expression in adipose and placental tissue obtained from pregnant women with and without GDM.

The IL-6/IL-6R/sgp130 system and Th17 associated cytokines in patients with gestational diabetes

INTRODUCTION Interleukin-6 (IL-6) is a pleiotropic cytokine which signals through a cell surface receptor complex consisting of a cognatereceptor subunit (IL-6R) and glycoprotein 130 (gp130), which is considered an antagonist to the IL-6R/IL-6 pathway. The aim of the present study was to assess IL-6/IL-6R/gp130 system and Th17 associated cytokines in different time points during and after pregnancy in women with gestational diabetes mellitus (GDM) and normal glucose tolerance (NGT). MATERIAL AND METHODS Serum levels of IL-6, sIL6R, sgp130, IL-17 and IL-23 were measured in 91 women divided into three groups: GDMin the 24th-28th week of gestation (visit 1), NGT at the 1st visit and GDM in the 29th-32nd week, and NGT at both visits. RESULTS The patients with GDM recognised at the 1st visit had significantly higher IL-6 (p = 0.02) and sgp130 (p = 0.03) concentrations than had the women with NGT, whereas the women with GDM diagnosed at the 2nd visit had elevated sIL-6R concentrations (p = 0.03). The patients with low sIL-6R but high sgp130 concentration had significantly higher glucose levels (p = 0.04) and lower IL-6 values (p = 0.04) than had the patients with low sIL-6R and sgp130 concentrations. IL-17 and IL-23 were detected in approximately one-third of the population studied. A trend towards higher IL-17 levels was observed in the subjects with GDM, but the differences were not significant. CONCLUSIONS Our results suggest that an increased serum sgp130 concentration in the patients with GDM might represent a compensatory mechanism, controlling intracellular IL-6 signalling and preventing the activation of the IL-6/IL-6R pathway.

The association of bone turnover markers with pro- and anti-inflammatory adipokines in patients with gestational diabetes

OBJECTIVE The aim of the study was to assess differences in circulating osteocalcin (OC) and osteoprotegerin (OPG), as well as in their expression in subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT) and placental tissue obtained from patients with gestational diabetes mellitus (GDM) and normal glucose tolerance (NGT). MATERIALS AND METHOD Serum levels of OC, OPG and soluble nuclear factor-kB ligand (sRANKL) were measured in 49 women with GDM and 30 subjects with NGT between weeks 24-32 of gestation, and three months after childbirth. OC and OPG mRNA expression was measured in 23 patients with GDM and 23 women with NGT at term, using quantitative real-time RT-PCR. RESULTS The patients with GDM had decreased OC mRNA expression in SAT (p=0.015), lower adiponectin mRNA expression in VAT (p=0.039), and a lower circulating adiponectin level (p=0.04). Multiple regression analysis revealed that serum adiponectin was significantly associated with OC mRNA expression in SAT (b=0.49, p=0.03). Three months postpartum, the OPG/sRANKL ratio was markedly higher in the subjects with prior GDM (p=0.03) and correlated positively with HbA1c (R=0.33; p=0.04), fasting insulin (R=0.35; p=0.03) and HOMA-IR (R=0.34; p=0.04). CONCLUSIONS In the patients with GDM decreased OC mRNA expression in SAT might be associated with a reduced stimulatory effect on adiponectin expression in adipose tissue. On the other hand, higher OPG/sRANKL ratio suggests a better protection against bone loss in the subjects with prior GDM.