Biomedical subjects

S Giunti

Publications and source records attributed to S Giunti.

7 recordsLinked to original sources

PubMed2001

Myocardial infarction before the age of 40 years is associated with insulin resistance.

Insulin resistance is associated with atherosclerosis, and hyperinsulinemia is predictive of coronary heart disease. However, a quantitative estimation of in vivo insulin sensitivity in juvenile myocardial infarction is still lacking and the mechanism of hyperinsulinemia is unknown. We estimated insulin sensitivity, beta-cell secretion, and hepatic insulin extraction using the minimal model analysis of a frequently sampled intravenous glucose tolerance test (FSIGT) in 25 normal-weight subjects without glucose intolerance and hypertension who had an acute myocardial infarction before the age of 40 years, and 10 control subjects comparable for age, sex, body mass index, and blood pressure. All patients underwent a coronary angiography. Insulin sensitivity was significantly lower in patients than in control subjects (mean +/- SEM, 4.6 +/- 0.6 v8.5 +/- 1.2 10(-4). min(-1)(microU/mL), P = .002). The basal C-peptide secretion rate (P = .02), total C-peptide secretion (P = .005), area under the curve (AUC) of insulin (P = .04) and C-peptide (P = .01), and hepatic insulin extraction (P = .04) were higher in patients versus control subjects. In conclusion, insulin resistance is evident in subjects with early myocardial infarction accurately selected to avoid the influence of other factors known to reduce insulin sensitivity, and hyperinsulinemia is due to an increase in beta-cell secretion rather than a decrease in hepatic insulin extraction.

Adult↗

PubMed2001

Autoantibody response to CD38 in Caucasian patients with type 1 and type 2 diabetes: immunological and genetic characterization.

Insulin secretion is one of the functions mediated by CD38, a nonlineage pleiotropic cell surface receptor. The molecule is the target of an autoimmune response, because serum autoantibodies (aAbs) to CD38 have been detected in diabetic patients. In the healthy Caucasian population, the CD38 gene is bi-allelic (86% CD38*B and 14% CD38*A), whereas an Arg140Trp mutation has been identified in Japanese diabetic patients. We investigated the relationship between CD38 and diabetes in Caucasian patients by characterizing anti-CD38 aAbs in terms of prevalence and function (agonistic/nonagonistic activity) and by exploring the potential influence of the CD38 genetic background. A novel enzymatic immunoassay, using recombinant soluble CD38 as the target antigen, was developed for the analysis of anti-CD38 aAb titers. Sera from 19.15% of type 1 and 16.67% of type 2 diabetic patients were positive. The majority of anti-CD38 aAbs (57.14%) displayed agonistic properties, i.e., they demonstrated the capability to trigger Ca2+ release in lymphocytic cell lines. In agreement with these functional features, the presence of anti-CD38 aAbs in type 2 diabetic patients was associated with significantly higher levels of fasting plasma C-peptide and insulin, as compared with anti-CD38-counterparts. No diabetic subject carrying the Arg140Trp mutation and no preferential association between diabetes or aAb status and the CD38*A allele was found in the study population. These results show the significance of anti-CD38 aAbs as a new diagnostic marker of beta-cell autoimmunity in diabetes. Moreover, the prevalent agonistic activity of these aAbs suggests that they could mediate relevant effects on target cells by means of Ca2+ mobilization.

ADP-ribosyl Cyclase↗

PubMed2000

Microvascular angina (cardiological syndrome X) per se is not associated with hyperinsulinaemia or insulin resistance.

BACKGROUND: Microvascular angina has been found to be associated with insulin resistance. However, many factors known to affect insulin sensitivity were not excluded in patient selection. We aimed to evaluate whether microvascular angina is per se associated with insulin resistance. MATERIALS AND METHODS: We performed a Frequently Sampled Intravenous Glucose Tolerance Test (0.33 g kg(-1) b.w.) in 10 normal weight and normotensive patients with microvascular angina, with normal glucose tolerance and normal plasma lipids. Ten healthy subjects, comparable for age, sex, body mass index, blood pressure and plasma lipids, were used as control group. RESULTS: Fasting serum glucose (4.49+/-0.2 SEM vs. 4.52+/-0.13 mmol L(-1), P = 0.9), insulin (39.46 +/-3.68 SEM vs. 47.12+/-4.6 pmol L(-1), P = 0.21) and C-peptide (0.56 +/-0.05 SEM vs. 0.53+/-0.05 nmol L(-1), P = 0. 68) values, as well as estimated parameters of insulin secretion and hepatic insulin extraction were similar in the two groups. Insulin sensitivity values (median, range) were also similar in the patients and control subjects (5.76 (3.39-12.30) vs. 7.54 (3.68-13.89. 10(-4) x min(-1)/(microU/mL), P = 0.97). CONCLUSION: Microvascular angina per se is not associated with hyperinsulinaemia or insulin resistance when other confounding factors are excluded in patient selection.

Adult↗

PubMed2000

[Epidemiologic analysis of the incidence of new diabetic patients on dialysis as a basis for a clinical study].

BACKGROUND: Aim of this study is to analyse the incidence of diabetic patients starting dialysis in Piedmont (Italy) during the period 1981-1996 and to evaluate, in a subgroup of patients, the causes of uremia (diabetic nephropathy or other), and the type and seriousness of comorbid factors, in order to define the clinical conditions and try to explain the causes incidence increase. METHODS: Data are taken from the RPDT (Regional Registry of Dialysis and Transplantation of Piedmont). RESULTS: Total incidence of new patients starting dialysis in this Region increased from 65 pmp in 1981-1982 to 116 pmp in 1995-1996 and the mean age increased from 55.4 +/- 15.5 years in 1981-1982 to 61.5 +/- 15.6 in 1995-1996; 49% of patients had at least one of the 13 conditions of comorbidity considered by the Registry (including severe vascular, cardiac, systemic diseases and diabetes). In the same period the incidence of diabetic patients increased from 6 pmp (1981-1982) to 19 for males and 12 pmp for females (1995-1996); this increase is higher for males and limited to patients with age > or = 60 years (for example: group 70-79 years from 7 to 56 pmp). A study performed in a group of 64 patients (52 type 2 and 12 type 1) showed the incidence of multiple comorbid factors: the most important in type 2 are vascular diseases (44/52) and heart diseases (20/52); blindness and amputations are relatively rare (2 each). An important comorbid factor in type 1 diabetes is blindness (3/12) and in this group the most frequent cause of uremia is diabetic nephropathy (DN) (9/12); in the group of type 2 patients nephroangiosclerosis and a clinical picture of progressive renal failure, without nephrotic syndrome, represents 48% of all diagnoses. CONCLUSIONS: These results underline the necessity of a strict collaboration with diabetologists and of an improvement of dedicated structures in order to meet the increase of this critical population.

Adult↗

PubMed2000

Apolipoprotein H is increased in type 2 diabetic patients with microalbuminuria.

BACKGROUND AND AIM: Serum apolipoprotein H (Apo H) levels are increased in hyperlipidemic subjects and type 2 diabetics, but unknown in microalbuminuria, another disorder with an increased cardiovascular risk. We looked to see whether increased Apo H levels are associated with microalbuminuria in type 2 diabetes. METHODS AND RESULTS: Serum Apo H was calculated in 20 normoalbuminuric and 17 microalbuminuric type 2 diabetics matched for age, sex, body mass index (BMI), glycosylated haemoglobin, plasma lipids and duration of diabetes, and also compared with 20 non-diabetic controls matched for age, sex, BMI and plasma lipids. Mean serum Apo H was significantly higher in the microalbuminuric patients (31.12 +/- 1.58 SEM vs 25.25 +/- 1.52 and 24.72 +/- 0.99 mg/dL, p = 0.003). CONCLUSION: Serum apo H levels are increased in type 2 diabetics with microalbuminuria.

Albuminuria↗

PubMed1998

Microalbuminuria in IDDM is associated with increased expression of monocyte procoagulant activity.

Microalbuminuria, the early phase of diabetic nephropathy, is associated with an increased risk of atherothrombosis. Monocytes play an important part in the pathogenesis of atherosclerosis and in the activation of haemostasis. However, procoagulant activity is poorly understood in Type I (insulin-dependent) diabetes mellitus, particularly in the presence of microalbuminuria. This study aimed to evaluate spontaneous and endotoxin-induced monocyte procoagulant activity in insulin-dependent diabetic patients with normoalbuminuria or microalbuminuria. Seventeen patients with microalbuminuria, 28 with normoalbuminuria and 26 healthy control subjects matched for age, sex, body mass index and smoking habit were studied. Mononuclear cells from peripheral venous blood were incubated with or without bacterial lypopolysaccharide. Spontaneous procoagulant activity and procoagulant activity after 3 h and 6 h of incubation were calculated. Spontaneous procoagulant activity values were similar in the three groups. After 3 h and 6 h incubation with bacterial lypopolysaccharide, procoagulant activity values were slightly, but not statistically significantly, higher in the normoalbuminuric diabetic group than in control group, and significantly higher in microalbuminuric diabetic group than in control group (p < 0.01). The increased endotoxin-induced monocyte procoagulant activity helps to explain the link between microalbuminuria and the increased risk of atherothrombosis in patients with Type I diabetes.

Adult↗

PubMed1994

Single-sweep analysis using an autoregressive with exogenous input (ARX) model.

Single-sweep visual evoked potential analysis would be useful in clinical electrophysiology practice because it would make possible the evaluation of transient phenomena, but recording single-sweep visual evoked potentials is difficult because of the low signal-noise ratio. To increase this ratio we used a filter based on an autoregressive with exogenous input model. We studied a group of 12 diabetic patients matched with a control group of 14 normal subjects. The model, in most cases, allowed us to extrapolate the P100 component from each single sweep of visual evoked potential. The visual evoked potential values obtained by means of averaging were not significantly different in the groups studied, but single-sweep analysis showed different distribution of the P100 component amplitude. The preliminary results of our study evidenced differences in the amplitude and latency distribution of normal and diabetic subjects, thus confirming the power of this new technique and its ability to obtain some information that is masked by the averaging method.

Adult↗