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.

CE-MS-based serum fingerprinting to track evolution of type 2 diabetes mellitus.

Development of type 2 diabetes mellitus (T2DM) is preceded by insulin resistance (IR), which may evolve to impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT). IFG and IGT are considered as prediabetic states (PD). Prediabetes indicates the high risk for the future development of diabetes, it is estimated that up to 70% of prediabetics eventually develop T2DM. The risk of T2DM development is increased in overweight (OW) and obese (OB) people; however normal weight (NW) individuals also suffer from T2DM. The present study was designed to evaluate whether changes in polar metabolites induced by T2DM evolution are different between NW, overweight and obese individuals. CE-MS serum fingerprinting was performed on 197 serum samples obtained from OW, OB, and NW humans whom were IR, prediabetics, diabetics or with normal glucose homeostasis. Metabolic changes evoked by the progression of T2DM differ between obese, overweight, and normal weight subjects. Based on obtained results several metabolites can be proposed as a promising target to track T2DM evolution; BCAA in OW and NW humans, lysine in OB, while acetylcarnitine and methionine independently on body mass index. Validation of obtained results on larger population is required.

The rs340874 PROX1 type 2 diabetes mellitus risk variant is associated with visceral fat accumulation and alterations in postprandial glucose and lipid metabolism.

Large-scale meta-analyses of genome-wide association studies have recently confirmed that the rs340874 single-nucleotide polymorphism in PROX1 gene is associated with fasting glycemia and type 2 diabetes mellitus; however, the mechanism of this link was not well established. The aim of our study was to evaluate the functional/phenotypic differences related to rs340874 PROX1 variants. The study group comprised 945 subjects of Polish origin (including 634 with BMI > 25) without previously known dysglycemia. We analyzed behavioral patterns (diet, physical activity), body fat distribution and glucose/fat metabolism after standardized meals and during the oral glucose tolerance test. We found that the carriers of the rs340874 PROX1 CC genotype had higher nonesterified fatty acids levels after high-fat meal (p = 0.035) and lower glucose oxidation (p = 0.014) after high-carbohydrate meal in comparison with subjects with other PROX1 genotypes. Moreover, in subjects with CC variant, we found higher accumulation of visceral fat (p < 0.02), but surprisingly lower daily food consumption (p < 0.001). We hypothesize that lipid metabolism alterations in subjects with the PROX1 CC genotype may be a primary cause of higher glucose levels after glucose load, since the fatty acids can inhibit insulin-stimulated glucose uptake by decreasing carbohydrate oxidation. Our observations suggest that the PROX1 variants have pleiotropic effect on disease pathways and it seem to be a very interesting goal of research on prevention of obesity and type 2 diabetes mellitus. The study may help to understand the mechanisms of visceral obesity and type 2 diabetes mellitus risk development.

Reduced intake of dietary antioxidants can impair antioxidant status in type 2 diabetes patients.

INTRODUCTION: Oxidative stress plays a major role in the pathogenesis of type 2 diabetes. OBJECTIVES: The objective of this study was to investigate associations between dietary intake of antioxidants and antioxidant status in patients with type 2 diabetes. PATIENTS AND METHODS: In 80 patients with type 2 diabetes and 37 controls, total antioxidant status (TAS), activities of glutathione peroxidase (GPx) and superoxide dismutase (SOD), malondialdehyde (MDA), and 4­hydroxyalkenals (4­HAE) were measured. The 24­hour food recall method and our own dietary database were used to calculate dietary total antioxidant capacity (DTAC), polyphenol content (DTPC), and flavonoid content (DTFC). Dietary antioxidant vitamins were calculated using national food composition databases. RESULTS: Serum TAS was 1.57 mmol/l in controls, 1.41 mmol/l in patients with newly diagnosed type 2 diabetes, and 1.23 mmol/l in patients with long-standing type 2 diabetes. Serum MDA and 4­HAE levels were 0.78 µmol/l in controls, 1.45 µmol/l in newly diagnosed diabetes, and 1.74 µmol/l in long-standing diabetes. GPx and SOD activities were 42.6 and 1340 units/g hemoglobin (Hb), respectively, in controls, 47.3 and 2373 units/g Hb in long-standing diabetes, and 58.2 and 3093 units/g Hb in newly diagnosed diabetes. DTAC, DTPC, DTFC, and vitamin C content were 5697 µmol Trolox equivalents (TE), 1031 mg gallic acid equivalents (GAE), 223 mg quercetine equivalents (QE), and 82 mg, respectively, in control diet. In patients with long-standing diabetes, the values were 4271 µmol TE, 822 mg GAE, 173 mg QE, and 63 mg, respectively, and in those with newly diagnosed type 2 diabetes, they were 4545 µmol TE, 839 mg GAE, 180 mg QE, and 65 mg, respectively. CONCLUSIONS: The diet of type 2 diabetes patients is poor in antioxidants despite increased demand.

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.

Serum irisin concentration in women with gestational diabetes.

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 IS(OGTT) (R = 0.22, p = 0.04) and the disposition index (DI(120)) (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 DI(120) were the only variables significantly influencing serum irisin (ß = 0.158, p = 0.03 and ß = 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.

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 (ß = -0.68, p = 0.03) and IL-8 mRNA expression (ß = 0.66, p = 0.03), whereas SOCS3 mRNA expression in VAT was independently predicted by IL-6 mRNA expression (ß = 0.94, p = 0.0002, R(2) = 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.