Increasing incidence of type 2 diabetes is a major health problem of the modern world and requires new diagnostic tools to assess early metabolic disorders, particularly insulin resistance. The link between obesity, inflammation and insulin resistance indicates the important secretory role of adipose tissue. Proinflammatory factors (cytokines, adipokines) produced by enlarged adipose tissue are related to impaired glucose metabolism. Adipokines act as paracrine factors in adipose tissue and as endocrine hormones in the liver, muscles and central nervous system. Novel adipokines secreted from adipocytes such as retinol binding protein-4 (RBP-4), vaspin, omentin, chemerin, fibroblast growth factor 21 (FGF21), adipocyte fatty acid-binding protein (A-FABP) and dipeptidyl peptidase 4 (DPP4) demonstrate pleiotropic activity and their insulin-sensitizing or enhancing insulin resistance properties have not been clearly confirmed yet. In spite of the lack of standardized automated assay methods currently available for these novel biomarkers, promising results from several studies emphasize that they might potentially be useful prognostic factors for diabetes and its complications, especially in individuals without the typical symptoms of metabolic syndrome.

Is there an association of allergy and cardiovascular disease?

The aim of the study was to evaluate the effect of a single freeze/thaw cycle on HbA1c concentrations measured by commercially available HPLC method. Study included 128 whole blood samples collected from diabetic patients (N = 60) and healthy volunteers (N = 68). HbA1c concentrations were measured in fresh blood samples. Then samples were frozen at - 80 °C for up to 12 weeks. HbA1c was assayed by ion-exchange HPLC method on Bio-Rad D-10® analyzer. Variables were compared using Wilcoxon and ANOVA Kruskal-Wallis tests. Bias between HbA1c measured in fresh and frozen samples was calculated. The comparability of HbA1c concentrations was assessed by Bland-Altman plot. Median (IQR) HbA1c concentration was 45.3 (36.6-61.2) mmol/mol for fresh and 45.3 (36.6-60.6) mmol/mol for frozen/thawed samples. No significant difference in HbA1c concentrations was found comparing fresh and frozen/thawed samples (P = 0.070) in the whole group, as well as in healthy and diabetic subjects. The median calculated bias between fresh and frozen/thawed samples was 0% in whole group and healthy subjects, and 1.19% in diabetic patients. No significant difference was found between the biases according to baseline HbA1c values (P = 0.150). The Bland-Altman plot analysis showed a positive bias of 0.4% (95% CI: - 2.8 - 3.7%), which indicates high compliance between HbA1c values and no relevant influence of sample freezing on clinical significance of HbA1c measurement. Storage for up to 12 weeks at - 80 °C with a single freeze/thaw cycle does not affect HbA1c concentrations measured with HPLC method on Bio-Rad D-10® analyzer.

Background: The aim of this study was to assess the relationship between vitamin D status and the prevalence of dyslipidemia and impaired fasting glucose (IFG) in children. Methods and Summary: 284 children (150 boys and 134 girls) aged 9–11 were included in the study. Children with deficient 25(OH)D (25-hydroxycholecalciferol) levels ≤20 ng/mL (50 nmol/L) were characterized by a more frequent occurrence of impaired fasting glucose (IFG) (Odd ratios (OR) = 1.966, 95% confidence interval (CI): 1.055–3.663; p = 0.033) when compared to children with 25(OH)D >20 ng/mL. Serum 25(OH)D with concentration lower by 1 ng/mL (2.5 nmol/L) was linked to higher fasting glucose (by 0.25 mg/dL, 0.013 mmol/L; p = 0.017), higher total cholesterol (TC) by almost 1 mg/dL (0.96 mg/dL, 0.25 mmol/L; p = 0.006) and higher high-density lipoprotein cholesterol (HDL-C) (by 0.57 mg/dL, 0.015 mmol/L; p < 0.001). Conclusion: 25(OH)D deficiency may negatively affect fasting glucose and total cholesterol concentration in children aged 9–11. Vitamin D-deficient children are twice as likely to develop prediabetes as reflected by impaired fasting glucose when compared to those with a 25(OH)D level above 20 ng/mL (50 nmol/L).

The associations between individual components of metabolic syndrome (MetS) and bone health in children are complex, and data on this topic are sparse and inconsistent. We assessed the relationship between bone turnover markers and markers of the processes underlying MetS (insulin resistance and inflammation) in a group of presumably healthy children aged 9–11 years: 89 (51 girls, 38 boys) presenting without any features of MetS and 26 (10 girls, 16 boys) with central obesity and two features of MetS. Concentrations of glucose, triglycerides (TG), HDL cholesterol (HDL-C), C-reactive protein (CRP), HbA1c, total 25-hydroxyvitamin D (25(OH)D), intact-P1NP (N-terminal propeptide of type I procollagen), CTX-1 (C-terminal telopeptide of type I collagen) were assayed and insulin resistance was assessed (HOMA-IR). BMI centile, waist circumference (WC) and blood pressure were measured. The presence of MetS in girls resulted in significantly lower concentrations of CTX-1 and a trend to lower CTX-1 in boys. The concentrations of bone formation marker i-P1NP were not affected. Among the features associated with MetS, HOMA-IR appeared as the best positive predictor of MetS in girls, whereas CRP was the best positive predictor in boys. A significant influence of HOMA-IR on the decrease in CTX-1 in girls was independent of BMI centile and WC, and the OR of having CTX-1 below the median was 2.8-fold higher/1SD increased in HOMA-IR (p = 0.003). A weak relationship between CTX-1 and CRP was demonstrated in girls (r = −0.233; p = 0.070). Although TG, as a MetS component, was the best significant predictor of MetS in both sexes, there were no correlations between bone markers and TG. We suggest that dyslipidemia is not associated with the levels of bone markers in prepubertal children whereas CRP is weakly related to bone resorption in girls. In prepubertal girls, insulin resistance exerts a dominant negative impact on bone resorption, independent of BMI centile and waist circumference.