Metabolic evaluation of urolithiasis patients from eastern Croatia

Metabolic parameters were determined in fasting blood serum, fasting first morning urine, and 24-hour urine of male patients with recurrent calcium oxalate stones (N = 26, age 39.1 +/- 6.2 years) as well as in male healthy controls (N = 18, age 35.0 +/- 7.1 years), recruited from the eastern part of Croatia. The 24-hour urinary calcium excretion was significantly higher (p < 0.01) for patients (5.6 +/- 2.5 mmol) than for controls (3.7 +/- 1.9 mmol), but potassium excretion was higher (p < 0.01) for controls (74.5 +/- 33.8 mmol) than for patients (49.2 +/- 15.7 mmol). The mean ionic activity product of calcium and oxalate ions, IAP(CaOx), calculated from the fasting first morning urine parameters, was 25% higher for patients than for controls, but the difference was not statistically significant (p > 0.05). Very strong correlation (r = 0.97) was obtained between IAP(CaOx) values and calculated Ogawa indices that were recommended for estimating the potential risk for calcium oxalate stone formation.     

Thyroid volume as measured by ultrasonography in patients With type 1 diabetes mellitus without thyroid dysfunction.

The aim of this cross-sectional study was to assess and compare thyroid volume and its derminants in a cohort of type 1 diabetes mellitus (DM1) and compare the results to a healthy control group. We studied 65 DM1 patients treated with an intensive insulin regimen and 65 matched controls. In all participants we evaluated weight, height, BMI, waist-hip ratio, body surface area and body composition variables determined by using a bioelectrical impedance analyser. Thyroid size was estimated by ultrasonography. We determined basal TSH, anti-thyroid antibodies and urinary iodine excretion. Body weight, height, BMI and body surface area were similar in DM1 patients and in controls. Fat-free mass was higher in both male and female DM1 patients than in controls (64.4 +/- 6.9 vs. 60.4 +/- 8.2 kg, p=0.03 and 48.3 +/- 5.7 vs. 45.4 +/- 6, p=0.04, respectively), and fat mass was lower in male DM1 patients than in controls (9.7 +/- 7 vs. 14.2 +/- 8.1 kg, p=0.01). Thyroid volume was greater in both male and female DM1 patients than in controls (11.12 +/- 2.87 vs. 9.63 +/- 2.27 ml, p=0.0001 and 9.5 +/- 2.3 vs. 7.7 +/- 2 ml, p=0.002, respectively). Urinary iodine excretion was similar in the two groups. In both DM1 patients and controls, thyroid volume correlated with weight, height, BMI, waist-hip ratio, body surface area, fat-free mass and the multivariate linear regression analysis with thyroid volume as the dependent variable showed that fat-free mass in either group was the only significant determinant of thyroid volume. We conclude that DM1 patients had larger thyroid volume compared with healthy controls with similar anthropometry; body composition is different in DM1 patients and that the anthropometric and body composition variables, especially fat-free mass and body surface area, predict thyroid volume either in DM1 patients or in healthy controls.     

Physiological relationships between growth hormone level, glycemia and metabolic control in dogs

This study was undertaken to explore the physiological relationships between fasting glycemia, antecedent glycemic control and fasting growth hormone levels in pancreatectomized dogs. In contrast to other studies, we used continuous intravenous infusions of insulin in an attempt not only to normalize fasting plasma glycemia but also to eliminate the characteristic fluctuations of diabetes usually encountered in the postprandial and postabsorptive periods. For comparison, a similar group of healthy animals served as normal controls. In the healthy dogs, fasting growth hormone (GH) levels were stable and well within normal limits for this species, demonstrating an overall mean +/- SD of 2.50 +/- 0.46 ng/ml. In the pancreatectomized group as a whole, the fasting GH levels were significantly elevated (4.63 +/- 2.42 ng/ml, P less than 0.01) and significantly (P less than 0.001) more variable than in the controls. Multiple regression and analysis of variance confirmed the expected significant positive correlation between fasting GH and fasting plasma glucose levels, but also elucidated a heretofore unknown direct relationship between fasting GH levels and the preceding instability of glycemic control.     

Effect of Various Clinical Variables on Total Intracellular Magnesium in Hospitalized Normomagnesemic Diabetic Patients before Discharge

Deficiency of intracellular magnesium (icMg) may coexist with normal serum Mg levels. Little is known about clinical and pharmacological factors affecting icMg in normomagnesemic patients with diabetes mellitus (DM). Moreover, no information exists regarding the icMg state in diabetic patients after acute illness and before hospital discharge. We have evaluated the effect of antihyperglycemic medications and other relevant clinical variables on icMg in 119 such patients. Total icMg was measured in peripheral blood mononuclear cells. Twenty healthy volunteers served as controls. IcMg content (μg/mg cell protein) was lower in DM compared to controls (1.74 ± 0.44 vs 2.4 ± 0.39, p < 0.001). It was also significantly lower in patients treated with insulin (1.57 ± 0.31 vs 1.8 ± 0.46, p = 0.01), while metformin treatment was associated with higher icMg (1.86 ± 0.49 vs 1.63 ± 0.35, p = 0.003). After adjustment for age, gender, and concomitant use of other hypoglycemic drugs, only treatment with metformin was independently associated with increased icMg (p = 0.03). No statistically significant association or correlation was found between icMg content and age, causes of hospitalization, comorbid conditions, treatment with other drugs, concentrations of HbA_1c, serum glucose, Mg, or creatinine. In conclusion, icMg is depleted in normomagnesemic DM patients. Insulin treatment is associated with worsening of icMg status, while metformin treatment may confer protective effect.     

MCA供血区急性脑梗死SWI图像与脑血管反应性的相关性

目的:分析大脑中动脉供血区(MCA)急性脑梗死患者的磁敏感加权成像(SWI),探讨梗死侧侧脑室旁深部髓质静脉(DMV)数量与脑血管反应性(CVR)的相关性。方法:回顾性纳入首次发生患侧MCA供血区卒中患者109例,并已完成TCD CO_2负荷实验和SWI等检查。根据SWI图像将DMV数量分为3级,5条为1级;5-10条为2级;10条为3级,分析DMV分级与CVR的关系。结果:根据排除标准共纳入MCA供血区急性脑梗死患者53例,DMV 1级、2级和3级分别有29、18、6例患者,MCA平均CVR为0.40±0.18。DMV 1级CVR为(0.45±0.22)、2级为(0.35±0.15)和3级为(0.20±0.11),3组患者间CVR存在明显差异(P0.05),且DMV 3级组较DMV 1级组、2级组显著降低(P0.05);Spearman相关分析表明,DMV分级与CVR间存在明显的负性相关关系(P0.001)。结论:MCA供血区脑梗死患者DMV分级与患侧MCA CVR呈负相关关系。     

Lysophosphatidylcholine molecular species in low density lipoprotein of type 2 diabetes.

To reveal the importance of lysoposphatidylcholine (LPC) in patients with Type 2 diabetes (DM), LPC in low density lipoprotein (LDL) was determined by high performance liquid chromatography in 38 patients with Type 2 DM and 31 age and sex-matched non-diabetic controls. Stearoyl LPC (SLPC) and palmitoyl LPC (PLPC) were detected in LDL. The contents of both LPCs per gram protein in LDL were increased in diabetic patients compared with the non-diabetics (1.99+/-0.94mg SLPC and 3.02+/-1.81 mg PLPC vs 1.47+/-0.57 mg SLPC and 2.30+/-0.83 mg PLPC, mean +/- SD, p < 0.01 and p < 0.05, respectively). PLPC showed a weak correlation with the levels of fasting plasma glucose (FPG) and HbA1c (r=0.27 and r=0.33, p < 0.05 and p < 0.01, respectively). The diabetic patients with macroangiopathy showed higher levels of PLPC per gram protein compared to those without macroangiopathy (4.60+/-2.61 mg vs 2.53+/1.15 mg, respectively, p < 0.05). The LPC molecular species may participate in the atherogenicity of LDL in patients with Type 2 diabetes.     

Periodontal disease status of pregnant women with diabetes mellitus

The aim of the present study was to evaluate the association between type I diabetes mellitus (DM) and periodontal disease in pregnant women. Fifty-two pregnant women aged 27.9 +/- 6.9 years with type I DM participated in the present study. Forty-two non-pregnant type I female diabetics (mean age: 27.9 +/- 6.1 years) and 121 healthy non-pregnant women (mean age: 29.1 +/- 5.7 years) without diabetes formed the control group. All subjects were given a clinical periodontal examination including probing pocket depth (PPD), probing attachment level (PAL), assessment of plaque and gingivitis scores (SBI). Blood parameters included levels of hemoglobin, glycosylated hemoglobin, total cholesterol, triglyceride and leukocytes. The pregnant diabetic subjects showed despite a good metabolic control significantly higher values for the SBI compared to the controls. Pregnant diabetic subjects displayed a significant correlation between the dose of insulin per day and PPD (p < or = 0.05) as well as the PAL (p < or = 0.05). In conclusion, the results of the study indicate that pregnant diabetics demonstrate a higher degree of periodontal inflammation and destruction compared to non-pregnant diabetics and healthy non-pregnant patients.     

Advanced glycation end-products and advanced oxidation protein products in patients with diabetes mellitus

Accelerated glycoxidation takes part in the development of diabetic complications. We determined advanced glycation end-products (AGEs) and advanced oxidation protein products (AOPP) in the sera of 52 patients with diabetes mellitus (DM) - 18 with DM Type 1 and 34 with DM Type 2 and examined their relationship to the compensation of the disease. AGEs were estimated spectrofluorimetrically (350 nm/440 nm) whereas AOPP were determined spectro-photometrically (340 nm). AGEs were elevated only in DM Type 2 (DM2 5.11+/-1.15 x 10(3) AU/g vs controls 4.08+/-0.71 x 10(3) AU/g, p<0.001, vs DM1 4.14+/-0.86 x 10(3) AU/g, p<0.005, DM1 vs controls were not significant). AOPP were elevated significantly in both types of DM with higher levels in DM Type 2 (DM2 157.50+/-75.15 micromol/l vs healthy subjects 79.80+/-23.72 micromol/l, p<0.001, vs DM1 97.50+/-30.91 micromol/l, p<0.005, DM1 vs controls p<0.05). There was a tight correlation between AGEs and AOPP in both types of DM (DM1 r=0.75, DM2 r=0.47 (p<0.05)) and both AGEs and AOPP correlated with triglycerides. In DM Type 1 only, AGEs correlated with HbA1c r=0.47 (p<0.05) and with blood glucose. Slight but not significant differences in AGEs and AOPP levels were observed in patients with or without diabetic complications. Oxidative stress is increased in both types of DM, more in Type 2 where it contributes to the formation of glycoxidation products.     

Reduced serum acylated ghrelin levels in patients with hyperthyroidism

BACKGROUND AND OBJECTIVE: Recent studies have revealed that circulating ghrelin levels seem to play a role in energy homeostasis. The effect of hyperthyroidism on ghrelin levels is not fully known. METHODS: Serum levels of ghrelin and its relationship with insulin resistance were evaluated in 48 patients with hyperthyroidism and 43 euthyroid healthy controls. Thyroid hormones, insulin, glucose, ghrelin levels and lipid parameters were measured in all subjects. Insulin sensitivity was determined using the homeostasis model assessment. RESULTS: Serum ghrelin levels were significantly decreased in hyperthyroid patients than in controls (32.5 +/- 23.3 vs. 54.1 +/- 35.5 pg/ml, p < 0.001). Circulating ghrelin levels significantly correlated with age (r = -0.26, p = 0.01), fasting glucose (r = -0.21, p = 0.01), free triiodothyronine (r = -0.18, p = 0.04), free thyroxine (r = -0.23, p = 0.02) and thyroid stimulating hormone (r = 0.21, p = 0.04), but not with blood pressure, body mass index, lipid parameters, insulin and homeostasis model assessment (p > 0.05). Multiple regression analysis revealed glucose level to be the most important predictor of circulating ghrelin level. CONCLUSION: These results indicate that hyperthyroidism has effect on serum ghrelin levels. Further studies are needed for the exact mechanism.     

Effect of Acute Inspiratory Muscle Exercise on Blood Flow of Resting and Exercising Limbs and Glucose Levels in Type 2 Diabetes

To evaluate the effects of inspiratory loading on blood flow of resting and exercising limbs in patients with diabetic autonomic neuropathy. Ten diabetic patients without cardiovascular autonomic neuropathy (DM), 10 patients with cardiovascular autonomic neuropathy (DM-CAN) and 10 healthy controls (C) were randomly assigned to inspiratory muscle load of 60% or 2% of maximal inspiratory pressure (PImax) for approximately 5 min, while resting calf blood flow (CBF) and exercising forearm blood flow (FBF) were measured. Reactive hyperemia was also evaluated. From the 20 diabetic patients initially allocated, 6 wore a continuous glucose monitoring system to evaluate the glucose levels during these two sessions (2%, placebo or 60%, inspiratory muscle metaboreflex). Mean age was 58 ± 8 years, and mean HbA1c, 7.8% (62 mmol/mol) (DM and DM-CAN). A PImax of 60% caused reduction of CBF in DM-CAN and DM (P<0.001), but not in C, whereas calf vascular resistance (CVR) increased in DM-CAN and DM (P<0.001), but not in C. The increase in FBF during forearm exercise was blunted during 60% of PImax in DM-CAN and DM, and augmented in C (P<0.001). Glucose levels decreased by 40 ± 18.8% (P<0.001) at 60%, but not at 2%, of PImax. A negative correlation was observed between reactive hyperemia and changes in CVR (Beta coefficient = -0.44, P = 0.034). Inspiratory muscle loading caused an exacerbation of the inspiratory muscle metaboreflex in patients with diabetes, regardless of the presence of neuropathy, but influenced by endothelial dysfunction. High-intensity exercise that recruits the diaphragm can abruptly reduce glucose levels.     

Soluble LDL-immune complexes in type 2 diabetes and vascular disease.

BACKGROUND AND AIMS: The oxidative modification of LDL has been shown to affect its clearance and to exert cytotoxic and immunogenic effects. The objective of our study was to analyse markers of LDL oxidation-soluble LDL containing immune complexes (LDL-ICs) in type 2 diabetes with micro- and macrovascular disease. PATIENTS AND METHODS: The study included 69 diabetic patients with coronary artery disease (DM + CAD), 78 non-diabetics with CAD, 47 controls, and 27 diabetics with nephropathy and 36 free from complications. OxLDL antibodies and advanced glycated end-products were measured by ELISA, and LDL-IC apo B content after PEG precipitation. RESULTS: Determination of a broad range of oxLDL antibody activity in all study groups showed no significant differences. In contrast, the content of apo B, a component of the antigen moiety of oxLDL-ICs, was higher in CAD and diabetes (+ CAD) than in LDL-ICs isolated from controls (p < 0.001). LDL-ICs did not differ between patients with CAD + DM and CAD patients free from diabetes. LDL-IC levels in diabetic patients with or without microangiopathy were significantly higher than in healthy volunteers (PEG-apo B 0.278 +/- 0.107 vs. 0.165 +/- 105 g/l, p < 0.002; PEG-IgG 151.7 +/- 76 vs. 115.4 +/- 62 g/l, p < 0.05). However, there was no significant difference in the level of circulating LDL-ICs between the subgroup of diabetic patients with nephropathy/retinopathy and patients free of microvascular disease (Ab-oxLDL 27.7 +/- 10.4 vs. 27.1 +/- 9.3 AU, NS; PEG-apo B 0.324 +/- 0.111 vs. 0.287 +/- 0.124 g/l, NS; PEG-IgG 1.68 +/- 0.68 vs. 1.42 +/- 0.80 g/l, NS). There was a statistically significant positive correlation between AGE content and LDL-ICs (r = 0.35, p < 0.009). A significant but inverse correlation was recorded between triglyceride concentration and level of LDL-ICs in DM + CAD (r = - 0.32, p < 0.016) and CAD patients (r = - 0.35, p < 0.002). A highly significant negative correlation between triglycerides and circulating LDL-ICs (r = - 0.54, p < 0.039) was observed in patients with early nephropathy, but not in those with physiological proteinuria. It is known that at a high triglyceride level in type 2 diabetes, the majority of LDL are small and dense, thus being more susceptible to oxidative modification. This could be a possible mechanism explaining why more LDL-ICs, with a level inversely correlating with triglyceride concentration, are generated in diabetes. CONCLUSION: The increased level of circulating LDL-ICs is a risk factor for the general population, including those with diabetes. Our results suggested the contribution of LDL-ICs to the development of atherosclerosis to probably be more significant than the direct contribution of oxLDLAb itself.     

Alteraciones del metabolismo glucídico en el estudio de control de factores de riesgo de Extremadura (estudio COFRE)

AimsTo assess the prevalence and control of glucose metabolism disorders in a population of Extremadura (Spain) with at least one cardiovascular risk factor and to compare the characteristics of these patients with those who were normoglycemic in the risk factor control in Extremadura (COFRE study).Patients and methodsThe prevalence and control of cardiovascular risk factors were recorded in a sample of 1,022 patients with at least one cardiovascular risk factor consecutively visiting a primary care office. Of these, 951 patients were included in the analysis. In all patients, fasting glycemia was recorded. Glycated hemoglobin was recorded in diabetic patients.ResultsA total of 320 patients (33.6%) were previously known to be diabetic (DM) and 84 (8.8%) had glycemia ≥126 mg/dl without a previous diagnosis of diabetes (12 with glycemia above 200 mg/dl). Impaired fasting glycemia (IFG) was found in 211 (22.2%) and normoglycemia (NG) in 336 (35.3%). Within the DM group, glycemia <126 mg/dl was found in only 31.4% but glycated hemoglobin lower than 7% was found in 46.8%. Triglyceride concentrations were higher in the IFG group than in the NG group (137±65 mg/dL vs 124±65 mg/dL, p=0,041). Pulse pressure was also higher, but no differences were found in diastolic blood pressure (DBP) or heart rate. Differences in systolic blood pressure (SBP) were at the limit of significance (DM 139.5±17 vs NG 136.5±16 mmHg; p=0.056). No significant differences were found in any of these parameters between the DM and IFG groups.ConclusionsThe prevalence of glucose metabolism disorders was very high in the recruited sample. Patients with IFG showed higher pulse pressure and triglyceride concentrations than those with NG but there were no differences in comparison with DM patients. Diabetic control was poor when assessed by fasting glycemia but glycated hemoglobin showed better control.     

Correlation between heat shock proteins,adiponectin, and T lymphocyte cytokine expression in type 2 diabetics

Type 2 diabetes mellitus (T2DM) features insulin resistance, hyperglycemia, dyslipidemia, overproduction of inflammatory cytokines, and systemic oxidative stress. Here, heat shock proteins Hsp70 and Hsp 90, adiponectin, and heme oxygenase-1 (HO-1, Hsp32) are profiled in peripheral blood mononuclear cells (PBMC) and serum from 25 T2DM patients and 25 healthy control subjects. Cells cultured with phorbol 12-myristate 13-acetate/ionomycin were evaluated by three-color flow cytometry for immunophenotypic biomarkers. Plasma HO-1, Hsp, and adiponectin levels were assayed by enzyme-linked immunosorbent assay (ELISA). Relative to healthy controls, T2DM patients exhibited significantly elevated plasma Hsp70, and representation of T helper immunophenotypes activated to express inflammatory cytokines, including CD4+ IFN-γ+, CD4+ TNF-α+, CD4+ IL-6+, CD4+ IL-1β+ T cells, significantly lower representation of CD4+ IL-10+ T cells, plasma adiponectin and cell-associated HO-1 expression—with no significant differences in plasma Hsp90 between T2DM and healthy controls. Plasma HO-1 and adiponectin in T2DM patients inversely correlated with TNF-α and showed inverse correlation between serum LDL and plasma HO-1. Moreover, TNF-α and Hsp90 in T2DM patients correlated positively with fasting blood glucose (FBG). These results demonstrate correlation between potentially pathogenic T cells, HO-1, and adiponectin, additionally revealing a T helper (Th)1-related character of T2DM immunopathogenesis, suggesting potential for novel T cell-related management strategies for T2DM and related co-morbidities.     

Serum nickel levels of diabetic patients and healthy controls by AAS with a graphite furnace

In this study, serum nickel levels of diabetic patients and healthy controls were determined by AAS with a graphite furnace. The serum nickel concentrations were found to be 1.15 +/- 1.89 micrograms/L in healthy controls and 0.82 +/- 0.74 microgram/L in diabetics. There was, however, no statistically significant difference between the two groups (p = 0.13). The relationship of nickel levels to diabetes type and duration, diabetic complications and treatment, sex, age, and heredity was investigated. However, again no significant differences were found, nor was there any correlation between serum nickel levels and blood sugar, HBa1c, fructosamine, sialic acid levels, and age.     

Association of serum adiponectin concentration to lipid and glucose metabolism in healthy humans.

BACKGROUND: Adiponectin is a recently discovered plasma protein with many associations to glucose and lipid metabolism. Due to its central role in cardiovascular diseases and insulin resistance, we studied the relationship between serum adiponectin and factors reflecting glucose and lipid metabolism. METHODS AND RESULTS: Thirty healthy participants (20M/10F, age 32.0 +/- 2.1 years, BMI 25.8 +/- 0.9 kg/m (2) and HbA (1c) 5.2 +/- 0.1 %) were studied four times at approximately one week intervals. The effects of a 4-hour euglycemic hyperinsulinemia (40 mU/m (2)/min), saline infusion (control), oral glucose, and oral fat load on serum adiponectin were studied. No significant correlation was found between serum adiponectin and insulin sensitivity before (r = 0.25) or after adjustment for age, BMI and gender (r = 0.04). Adiponectin concentration correlated inversely with HbA (1c) (r = - 0.43, p < 0.05), insulin concentration (r = - 0.38, p < 0.05) and triglyceride concentration (r = - 0.42, p < 0.05) but positively with HDL cholesterol (r = 0.38, p < 0.05). Metabolic procedures had no effect on serum adiponectin. CONCLUSIONS: Our findings favor the interpretation that adiponectin is not causally related to insulin sensitivity in healthy participants. The strongest associations of adiponectin in healthy participants are to be found to lipid metabolism. Serum levels of adiponectin are very stable and not acutely affected by hyperinsulinemia, oral glucose or fat load.     

Effect of Diabetes Mellitus Type 2 on Salivary Glucose – A Systematic Review and Meta-Analysis of Observational Studies

Background

Early screening of type 2 diabetes mellitus (DM) is essential for improved prognosis and effective delay of clinical complications. However, testing for high glycemia often requires invasive and painful blood testing, limiting its large-scale applicability. We have combined new, unpublished data with published data comparing salivary glucose levels in type 2 DM patients and controls and/or looked at the correlation between salivary glucose and glycemia/HbA1c to systematically review the effectiveness of salivary glucose to estimate glycemia and HbA1c. We further discuss salivary glucose as a biomarker for large-scale screening of diabetes or developing type 2 DM.

Methods and Findings

We conducted a meta-analysis of peer-reviewed published articles that reported data regarding mean salivary glucose levels and/or correlation between salivary glucose levels and glycemia or HbA1c for type 2 DM and non-diabetic individuals and combined them with our own unpublished results. Our global meta-analysis of standardized mean differences on salivary glucose levels shows an overall large positive effect of type 2 DM over salivary glucose (Hedge''s g = 1.37). The global correlation coefficient (r) between salivary glucose and glycemia was large (r = 0.49), with subgroups ranging from medium (r = 0.30 in non-diabetics) to very large (r = 0.67 in diabetics). Meta-analysis of the global correlation between salivary glucose and HbA1c showed an overall association of medium strength (r = 0.37).

Conclusions

Our systematic review reports an overall meaningful salivary glucose concentration increase in type 2 DM and a significant overall relationship between salivary glucose concentration and associated glycemia/HbA1c values, with the strength of the correlation increasing for higher glycemia/HbA1c values. These results support the potential of salivary glucose levels as a biomarker for type 2 DM, providing a less painful/invasive method for screening type 2 DM, as well as for monitoring blood glucose levels in large cohorts of DM patients.     

Effect of nutrient ingestion on glucagon-like peptide 1 (7-36 amide) secretion in human type 1 and type 2 diabetes.

Exogenous glucagon-like peptide 1(GLP-1) bioactivity is preserved in type 2 diabetic patients, resulting the peptide administration in a near-normalization of plasma glucose mainly through its insulinotropic effect. GLP-1 also reduces meal-related insulin requirement in type 1 diabetic patients, suggesting an impairment of the entero-insular axis in both diabetic conditions. To investigate this metabolic dysfunction, we evaluated endogenous GLP-1 concentrations, both at fasting and in response to nutrient ingestion, in 16 type 1 diabetic patients (age = 40.5 +/- 14yr, HbA1C = 7.8 +/- 1.5%), 14 type 2 diabetics (age = 56.5 +/- 13yr, HbA1C = 8.1 +/- 1.8%), and 10 matched controls. In postabsorptive state, a mixed breakfast (230 KCal) was administered to all subjects and blood samples were collected for plasma glucose, insulin, C-peptide and GLP-1 determination during the following 3 hours. In normal subjects, the test meal induced a significant increase of GLP-1 (30', 60': p < 0.01), returning the peptide values towards basal concentrations. In type 2 diabetic patients, fasting plasma GLP-1 was similar to controls (102.1 +/- 1.9 vs. 97.3 +/- 4.01 pg/ml), but nutrient ingestion failed to increase plasma peptide levels, which even decreased during the test (p < 0.01). Similarly, no increase in postprandial GLP-1 occurred in type 1 diabetics, in spite of maintained basal peptide secretion (106.5 +/- 1.5 pg/ml). With respect to controls, the test meal induced in both diabetic groups a significant increase in plasma glucagon levels at 60' (p < 0.01). In conclusion, either in condition of insulin resistance or insulin deficiency chronic hyperglycemia, which is a common feature of both metabolic disorders, could induce a progressive desensitization of intestinal L-cells with consequent peptide failure response to specific stimulation.     

Logistic model of glucose-regulated C-peptide secretion: hysteresis pathway disruption in impaired fasting glycemia

The present analysis tests the hypothesis that quantifiable disruption of the glucose-stimulated insulin-secretion dose-response pathway mediates impaired fasting glycemia (IFG) and type 2 diabetes mellitus (DM). To this end, adults with normal and impaired fasting glycemia (NFG, n = 30), IFG (n = 32), and DM (n = 14) were given a mixed meal containing 75 g glucose. C-peptide and glucose were measured over 4 h, 13 times in NFG and IFG and 16 times in DM (age range 50-57 yr, body mass index 28-32 kg/m(2)). Wavelet-based deconvolution analysis was used to estimate time-varying C-peptide secretion rates. Logistic dose-response functions were constructed analytically of the sensitivity, potency, and efficacy (in the pharmacological sense of slope, one-half maximal stimulation, and maximal effect) of glucose's stimulation of prehepatic insulin (C-peptide) secretion. A hysteresis changepoint time, demarcating unequal glucose potencies for onset and recovery pathways, was estimated simultaneously. According to this methodology, NFG subjects exhibited distinct onset and recovery potencies of glucose in stimulating C-peptide secretion (6.5 and 8.5 mM), thereby defining in vivo hysteresis (potency shift -2.0 mM). IFG patients manifested reduced glucose onset potency (8.6 mM), and diminished C-peptide hysteretic shift (-0.80 mM). DM patients had markedly decreased glucose potency (18.8 mM), reversal of C-peptide's hysteretic shift (+4.5 mM), and 30% lower C-peptide sensitivity to glucose stimulation. From these data, we conclude that a dynamic dose-response model of glucose-dependent control of C-peptide secretion can identify disruption of in vivo hysteresis in patients with IFG and DM. Pathway-defined analytic models of this kind may aid in the search for prediabetes biomarkers.     

Postocclusive reactive hyperemia inversely correlates with urinary 15-F2t-isoprostane levels in systemic sclerosis

Microvascular dysfunction and increased oxidative stress are major hallmarks of the systemic sclerosis disease process. The primary objective of this study was to test whether there is a link between peak postocclusive hyperemia and urinary levels of the F2-isoprostane 15-F2t-IsoP (8-iso-PGF2alpha) in patients suffering from systemic sclerosis. We enrolled 43 patients suffering from systemic sclerosis, 33 patients with primary Raynaud's phenomenon (RP), and 25 healthy volunteers. Microvascular function was assessed using the postocclusive hyperemia monitored by laser Doppler flowmetry. Endothelium-independent response was monitored after 0.4 mg sublingual nitroglycerin. Oxidative stress status was assessed by urinary levels of the F2-isoprostane 15-F2t-IsoP using GC-MS. The peak postocclusive vascular conductance was altered in subjects with systemic sclerosis and primary RP compared to controls (respectively 28 (7-48), 30 (13-48), and 39.9 (13-63) mV/mm Hg, p = 0.01). F2-isoprostanes were increased in the systemic sclerosis group compared to primary Raynaud's phenomenon and healthy controls (respectively 230 (155-387), 182 (101-284), and 207 (109-291) pg/mg, p = 0.006). In patients suffering from systemic sclerosis, there was a significant inverse correlation between F2-isoprostanes and postocclusive hyperemia, expressed as raw data (R = -0.45, p = 0.007) or as an increase over baseline (R = -0.28, p = 0.04). Conversely, no correlation was found with the nitroglycerin response. In conclusion, we provide evidence that there is an inverse correlation between postocclusive hyperemia and urinary F2-isoprostane levels in patients suffering from systemic sclerosis. Whether oxygen free radicals initiate the vascular dysfunction or whether there is an initial trigger that initiates both processes will need to be further clarified in future studies.     

Circulating expression levels of CircHIPK3 and CDR1as circular-RNAs in type 2 diabetes patients

Background

Recent investigations suggested that deregulated levels of Circular RNAs (circRNAs) could be associated with type 2 diabetes mellitus (T2DM) pathogenesis. Accordingly, this study aimed to determine the expression levels of circulating CircHIPK3, CDR1as and their correlation with biochemical parameters in patients with T2DM, pre-diabetes and control subjects.

Methods and results

The expression of circRNAs in peripheral blood was determined using QRT-PCR in 70 patients with T2DM, 60 pre-diabetes and in 69 age and sex matched healthy controls. Moreover, bioinformatics tools were applied to explore and predict the potential interactions between circRNAs and other non-coding RNAs (ncRNAs). Our analysis revealed that the expression level of CircHIPK3 was significantly elevated in T2DM patients compared to healthy participants (P?<?0.001) and pre-diabetes subjects (P?=?0.018). In addition, ROC analysis suggested that at the cutoff value of 0.24 and the sensitivity and specificity of 50% and 88.4%, respectively, CircHIPK3 could distinguish between T2DM patients and control subjects. Furthermore, it was observed that the expression level of CDR1as is higher in pre-diabetic individuals than healthy individuals (P?=?0.004). Finally, Spearman correlation analysis showed that there was a significant correlation between CircHIPK3 and CDR1as expression levels and clinical and anthropometrical parameters such as BMI, systolic and diastolic blood pressure, HbA1c and fasting blood glucose (P?<?0.005).

Conclusions

The data of this study provided evidence that the expression levels of CircHIPK3, CDR1as increased in T2DM and pre-diabetes subjects, respectively.