E. Vitacolonna

In Vivo Formation of 8-Iso-Prostaglandin F2α and Platelet Activation in Diabetes Mellitus Effects of Improved Metabolic Control and Vitamin E Supplementation

Background—Diabetes mellitus (DM) is associated with enhanced lipid peroxidation and persistent platelet activation. We tested the hypothesis that the in vivo formation of the F2-isoprostane 8-iso-prostaglandin (PG)F2α, a bioactive product of arachidonic acid peroxidation, is enhanced in DM and contributes to platelet activation. Methods and Results—Urine samples were obtained from 85 diabetic patients and 85 age- and sex-matched healthy subjects for measurement of immunoreactive 8-iso-PGF2α and 11-dehydro-thromboxane B2 (TXM), an in vivo index of platelet activation. Sixty-two had non–insulin-dependent (NID)DM, and 23 had insulin-dependent (ID) DM. Vitamin E supplementation, metabolic control, and cyclooxygenase inhibitors were used to investigate the mechanisms of formation of 8-iso-PGF2α in this setting. Urinary 8-iso-PGF2α excretion was significantly higher (P=0.0001) in NIDDM patients (419±208 pg/mg creatinine; range 160 to 1014) than in age-matched control subjects (208±92; 41 to 433). Urinary 8-iso...

The recovery of platelet cyclooxygenase activity explains interindividual variability in responsiveness to low-dose aspirin in patients with and without diabetes

See also Lordkipanidze M, Harrison P. Aspirin twice a day keeps new COX‐1 at bay. This issue, pp 1217–9.

Glucose and insulin independently reduce the fibrinolytic potential of human vascular smooth muscle cells in culture

Summary Hyperglycaemia and hyperinsulinaemia have both been related to accelerated atherosclerosis in non-insulin-dependent diabetes mellitus (NIDDM). Plasma fibrinolytic potential is reduced in NIDDM and it is known that glucose and insulin can modulate plasminogen activator inhibitor (PAI-1) and tissue-plasminogen activator (t-PA) secretion and can therefore regulate local fibrinolysis. Vascular smooth muscle cells (vSMC) play an important role in the development of atherosclerotic lesions; however, the role of insulin and glucose in regulating PAI-1 and t-PA production in vSMC is presently not known. Therefore, we cultured arterial vSMC explanted from human umbilical cords and exposed them to increasing concentrations of glucose (5, 12, 20, 27, 35 mmol/l) or insulin (0.1, 0.5, 1, 10 nmol/l) in a serum free medium. After 24 h, PAI-1 and t-PA antigens and activity were evaluated in the culture medium; in cells exposed to 20 mmol/l glucose and to 0.5 nmol/l insulin PAI-1 gene expression was also evaluated. An increase in PAI-1 antigen was observed at each glucose concentration (by 138, 169, 251 and 357 % as compared to 5 mmol/l glucose) which was paralleled by an increase in PAI-1 activity. t-PA concentration was also increased by glucose but its activity was sharply reduced. An increase in PAI-1 antigen was detected at each insulin level (by 121, 128, 156 and 300 % as compared to no insulin). PAI-1 activity was slightly increased at the lowest insulin concentrations but markedly increased by 10 nmol/l insulin. t-PA antigen was also increased by insulin; however, its activity was markedly reduced at each concentration. As compared to control cells, PAI-1 mRNA was increased by 2.5 and 2.0 fold by 20 mmol/l glucose and 0.5 nmol/l insulin, respectively. We conclude that in human vSMC both glucose and insulin can affect the fibrinolytic balance so as to reduce fibrinolytic potential. This might contribute to decreased local fibrinolysis and thereby might accelerate the atherothrombotic process in NIDDM subjects. [Diabetologia (1996) 39: 1425–1431]

Perinatal outcomes associated with the use of glargine during pregnancy

Aims  Insulin glargine (IG), with its non‐peaking action profile, might be useful in diabetic pregnancy. However, data on its safety are limited and its use during pregnancy is not recommended. This study focused on the effects of IG on perinatal outcome, particularly to estimate the rate of congenital anomalies and birthweight.

Type 1 diabetes control and pregnancy outcomes in women treated with continuous subcutaneous insulin infusion (CSII) or with insulin glargine and multiple daily injections of rapid-acting insulin analogues (glargine-MDI).

AIM The best way to treat pregnant patients who have type 1 diabetes is still unclear. For this reason, the present study compared metabolic control and maternal-fetal outcomes in patients treated with continuous subcutaneous infusions of rapid-acting insulin analogues (CSII) or with insulin glargine and multiple daily injections of rapid-acting insulin analogues (glargine-MDI). METHODS This retrospective multicentre study involved 144 women with type 1 diabetes, 100 of whom were using CSII and 44 glargine-MDI. Outcomes analyzed were metabolic control, diabetes complications, pregnancy outcome, perinatal morbidity and mortality, and fetal malformations. RESULTS The two groups were comparable for age, prepregnancy BMI, primiparous rate and diabetes complications, although patients using CSII had longer duration of diabetes (P=0.03) and higher White classifications (P=0.04). In both groups, metabolic control improved during pregnancy, but good control was reached earlier among patients using CSII. At parturition, patients using CSII had lower HbA(1c) (6.2±0.7% vs 6.5±0.8%; P=0.02) and required less insulin (P<0.01). Weight gain was similar in both groups, and maternal-fetal outcomes did not differ. CONCLUSION In pregnant patients with type 1 diabetes, MDI and CSII are equivalent in terms of metabolic control and fetal-maternal outcomes, although patients using CSII achieved good control earlier and with less insulin.

A novel flow cytometric approach to distinguish circulating endothelial cells from endothelial microparticles: Relevance for the evaluation of endothelial dysfunction

Circulating endothelial cells (CEC) and endothelial microparticles (EMP) are emerging as markers of endothelial repair and activation/apoptosis. Although significant changes in the number of CEC and EMP in pathological conditions have been reported, their reliable identification and quantification still remain a technical challenge. Here, we present a novel methodology for the identification and quantitation of CEC and EMP based on multicolor flow cytometry. Using a lyse/no wash protocol, we observed that in 50 μl of peripheral blood, the large majority of events expressing an endothelial phenotype (CD45-/CD146+/CD34+) are due to non-nucleated particles (DRAQ5-) carrying mitochondrial activity (MitoTracker+) and, therefore, classified as EMP. We enumerated circulating EMP by single platform absolute count in a lyse/no wash four-color flow-cytometric procedure, which allowed the distinction, within the whole endothelial compartment, of EMP derived from endothelial progenitors (CD45-/CD146+/CD34+/CD117+) and from mature endothelial cells (CD45-/CD146+/CD34+/CD117-). A significant increase in both subsets was observed in patients with diabetes mellitus. Thus, this simple and highly reproducible method may be useful for monitoring endothelial dysfunction in clinical settings.

Neuroretinal alterations in the early stages of diabetic retinopathy in patients with type 2 diabetes mellitus.

PurposeTo study neuroretinal alterations in patients affected by type 2 diabetes with no diabetic retinopathy (DR) or mild nonproliferative diabetic retinopathy (NPDR) and without any sign of diabetic macular edema.Patients and methodsIn total, 150 type 2 diabetic patients with no (131 eyes) or mild NPDR (19 eyes) and 50 healthy controls were enrolled in our study. All underwent a complete ophthalmologic examination, including Spectral-Domain optical coherence tomography (SD-OCT). Ganglion cell-inner plexiform layer (GC-IPL) and retinal nerve fiber layer (RNFL) thickness values were calculated after automated segmentation of SD-OCT scans.ResultsMean best-corrected visual acuity was 0.0±0.0 LogMAR in all the groups. Mean GC-IPL thickness was 80.6±8.1 μm in diabetic patients and 85.3±9.9 μm in healthy controls, respectively (P=0.001). Moreover, evaluating the two different diabetic groups, GC-IPL thickness was 80.7±8.1 μm and 79.7±8.8 μm in no-DR and mild-NPDR group (P=0.001 and P=0.022 compared with healthy controls, respectively). Average RNFL thickness was 86.1±10.1 μm in diabetes patients and 91.2±7.3 μm in controls, respectively (P=0.003). RNFL thickness was 86.4±10.2 μm in no-DR group and 84.1±9.4 μm in mild-NPDR group (P=0.007 and P=0.017 compared with healthy controls, respectively).ConclusionWe demonstrated a significantly reduced GC-IPL and RNFL thickness values in both no-DR and mild-NPDR groups compared with healthy controls. These data confirmed neuroretinal alterations are early in diabetes, preceding microvascular damages.

Gestational Diabetes and Thyroid Autoimmunity

Background. About 10% of pregnancies are complicated by previously unknown impairment of glucose metabolism, which is defined as gestational diabetes. There are little data available on prevalence of thyroid disorders in patients affected by gestational diabetes, and about their postgestational thyroid function and autoimmunity. We therefore investigated pancreatic and thyroid autoimmunity in gestational diabetic patients and in women who had had a previous gestational diabetic pregnancy. Methods. We investigated 126 pregnant women at the time of a 100-g oral glucose tolerance test: 91 were classified as gestational diabetics, and 35 were negative (controls). We also studied 69 women who had delivered a baby 18–120 months prior to this investigation and who were classified at that time gestational diabetics (38 women) or normally pregnant (31 women; controls). Results. Our data show no differences for both thyroid function and prevalence of autoimmune disorders during pregnancy; however, a significant increase in thyroid autoimmunity was seen in women previously affected by gestational diabetes. This increased prevalence of thyroid autoimmunity was not associated with the development of impaired glucose metabolism after pregnancy. Conclusions. Our data suggest that maternal hyperglycemia is a risk factor for the development of thyroid autoimmunity, a conclusion that should now be confirmed in a larger cohort of patients.

Insulin requirement of simple and complex carbohydrate foods in type 1 (insulin-dependent) CSII-treated diabetic subjects, obtained by Biostator. Correlation with glycaemic index

SummaryThe aim of this work was to observe whether different types of carbohydrates might require different insulin doses. Five type 1 CSII-treated diabetic subjects (age 39±4 years), C-peptide negative and in optimal metabolic control (HbA1c 7.5±0.2) were selected for the study. They were connected to the Biostator 6 times with an interval of 4–10 days between sessions and fed a meal containing 75 g of carbohydrates of different types: bread, pasta, potatoes, apples, oranges and sucrose. The following net (above basal) insulin requirement for the 30 meals were found (IU-mean+SD): bread 9.15±1.97; pasta 6.00±1.37; potatoes 7.05±2.58; apples 4.54±1.42; oranges 6.21±2.62; sucrose 7.83±2.33. A statistically significant difference was found by ANOVA among insulin requirements for foods (p<0.05). Single comparisons between bread and the other foods showed a statistically significant difference only between bread and apple (p<0.05). Mean coefficient of variation was 33.9% for the subjects and 30.7% for the meals. A significant correlation was found between Jenkins’ glycaemic index and insulin requirement (r=0.897; p<0.001). In conclusion, the high intraindividual variability of insulin requirement does not advice the use of the glycaemic index during optimized insulin therapy.

Nutrigenetic variants and cardio-metabolic risk in women with or without gestational diabetes

AIM Gestational diabetes mellitus (GDM) is the most frequent metabolic disorder in pregnancy and it can be considered a silent risk associated to T2DM and CVD later in life. The aim of this study was to investigate the association of clinical parameters with nine single nucleotide polymorphisms (SNPs) involved with nutrients and metabolism in women with or without GDM in order to identify potential routine clinical markers for early prevention. METHODS Nine gene variants associated with nutrients and metabolism, namely PPARG2 rs1801282 (C > G); PPARGC1A rs8192678 (C > T); TCF7L2 rs7903146 (C > T); LDLR rs2228671 (C > T); MTHFR rs1801133 (C > T); APOA5 rs662799 (T > C); GCKR rs1260326 (C > T); FTO rs9939609 (T > A); MC4R rs17782313 (T > C) were genotyped in 104 GDM cases and 124 controls using High Resolution Melting (HRM) analysis. RESULTS The genetic variant rs7903146 (C > T) in TCF7L2 gene showed a strong association with GDM risk (OR: 2.56; 95% CI: [1.24-5.29]). Moreover, a significant correlation was observed between lipid parameters and polymorphisms in other genes, namely PPARG2 [p = 0,03], APOA5 [p = 0,02], MC4R [p = 0,03], LDLR [p = 0,04] and FTO [p = 0,03]. In addition, rs17782313 variant, mapped close to MC4R gene, was associated to BMI in pre-pregnancy [p = 0,02] and at the end of pregnancy [p = 0,03] in GDM group. CONCLUSION In our study, we found significant associations between routine clinical parameters and some gene variants connected with nutrients and metabolism in women with GDM. These results can provide useful information to develop effective tools and possible personalized intervention strategies in a timely manner.