Effect of insulin and sulfonylurea therapy, at the same level of blood glucose control, on low density lipoprotein subfractions in type 2 diabetic patients.

The aim of this study was to evaluate the effect of sc insulin (INS) compared with sulfonylurea (SUL) therapy, at the same level of blood glucose control, on the low density lipoprotein (LDL) subfraction profile in normolipidemic type 2 diabetic patients. Nine normolipidemic type 2 diabetic men (age, 56+/-3 yr; body mass index, 26.5+/-0.9 kg/m2; mean +/- SEM), after a 3-week wash-out period, were assigned to INS or SUL for 2 months in a randomized cross-over design. Doses were adjusted only during the first month and then were kept constant. At the end of the treatments, hemoglobin A1c, plasma lipids, LDL, and very low density lipoprotein (VLDL) subfraction profiles and plasma postheparin lipoprotein lipase and hepatic lipase (HL) activities were evaluated. Despite glucose control was similar at the end of both periods (hemoglobin A1c, 7.4+/-0.3% vs. 7.0+/-0.2%, INS vs. SUL), INS compared with SUL significantly reduced plasma triglyceride (0.9+/-0.1 vs. 1.1+/-0.1 mmol/L; P < 0.05). Although INS did not affect the LDL concentration, it induced a decrease in both the amount (59.0 = 9.8 vs. 76.1+/-16.8 mg/dL; P = NS) and the proportion (31.2+/-3.0% vs. 38.3+/-3.8%; P < 0.03) of small LDL. Moreover, the decrease in small LDL was positively related to the reduction of large VLDL (r = 0.67; P < 0.04) and HL (r = 0.69, P < 0.05) induced by insulin therapy. In conclusion, sc insulin therapy, independently of glucose control and even in the presence of quite low plasma triglyceride levels, is able to reduce small LDL particles in type 2 diabetic patients. This change is related to decreases in both HL activity and large VLDL particles.

Insulin and sulfonylurea therapy in NIDDM patients. Are the effects on lipoprotein metabolism different even with similar blood glucose control?

This study evaluates the effects of insulin versus glibenclamide on lipoprotein metabolism at comparable levels of blood glucose control, in particular on the concentration and distribution of VLDL subfractions and lipolytic enzyme activities in nine NIDDM men (aged 56 +/- 3 years, BMI 26.5 +/- 0.9 kg/m2) (means +/- SE) participating in a crossover study. After a 3-week washout period, patients were randomly assigned to 2-month treatment periods (insulin or glibenclamide); thereafter, each patient crossed to the other treatment. At the end of each period, mean daily blood glucose (MDBG), HbA1e, plasma lipids, lipoproteins (VLDL, LDL, HDL), lipoprotein subfractions (VLDL1, 2, 3; HDL2, HDL3), and post-heparin lipase activities (lipoprotein lipase [LPL], hepatic lipase [HL]) were evaluated. Although glucose control was similar at the end of both periods (MDBG 8.3 +/- 0.3 vs. 7.9 +/- 0.3 mmol/l; HbA1c 7.4 +/- 0.3 vs. 7.0 +/- 0.2%, insulin versus glibenclamide), insulin compared with glibenclamide induced a significant reduction in plasma triglycerides (0.9 +/- 0.1 vs. 1.1 +/- 0.1 mmol/l, P < 0.05), VLDL triglycerides (50.1 +/- 12.2 vs. 63.6 +/- 12.3 mg/dl, P < 0.02), VLDL1 lipid concentration (24.9 +/- 7.5 vs. 39.9 +/- 9.5 mg/dl, P < 0.006), and increased HDL2 cholesterol (25.2 +/- 1.6 vs. 20.3 +/- 1.3 mg/dl, P < 0.03). In terms of VLDL percentage subfraction distribution, with insulin, there was a decrease in the larger subfractions (VLDL1 26.5 +/- 3.0 vs. 37.8 +/- 3.4%, P < 0.02) and an increase in the smallest (VLDL3 47.3 +/- 3.8 vs. 37.3 +/- 3.3%, P < 0.05). Moreover, HL activity was significantly lower after insulin than after glibenclamide (HL 247.2 +/- 22.3 vs. 263.5 +/- 22.6 mU/ml, P < 0.05). In conclusion, compared with glibenclamide, insulin treatment (independent of variations in glucose control) is able to decrease significantly plasma triglycerides, to increase HDL2 cholesterol, and to reduce only the concentration of the larger VLDL subfractions, with a consequent redistribution of their profile.

Cardiac performance and mass in adults with hypopituitarism: effects of one year of growth hormone treatment.

We studied the effects of GH administration on myocardial structure and function in 20 patients with hypopituitarism (14 males and 6 females; mean +/- SE age, 47.2 +/- 2.6 yr; range, 31-59 yr) developed in adulthood because of pituitary or parapituitary tumors. All patients had GH deficiency (GHD), as assessed by a GH response of less than 4 micrograms/L to a standard insulin tolerance test (0.05 U kg, iv) and the combined pyridostigmine (120 mg, orally, at -60 min) plus GHRH (1 microgram/kg, iv, at 0 min) test. Patients received either placebo (n = 10) or GH substitution therapy (n = 10; 0.05 U/kg.day GH for 1 yr; 0.03 U/kg.day during the first month). M- and B-mode echocardiography and pulsed Doppler examination of transmitral flow were performed before treatment, 6 months and 1 yr after starting GH or placebo administration, and 15 days and 3 months after GH or placebo withdrawal. Twenty healthy subjects, matched for age, sex, body mass index, and physical activity, served as controls. Left ventricular dimensions, mass, and systolic function were normal in patients with adult-onset GHD; however, diastolic function, specifically E wave deceleration time, was altered. GH administration markedly increased left ventricular performance and reversed diastolic abnormalities at 6 and even more so at 12 months. On the other hand, a clear increase in left ventricular mass was seen after 12, but not after 6, months of GH administration (P < 0.01 vs. pretreatment values). In addition, although all changes induced by GH treatment disappeared within 3 months after GH withdrawal, at that time the increase in left ventricular mass was still detectable (P < 0.05 vs. pretreatment values). These data indicate that augmented left ventricular contractility is not strictly related to cardiac muscle growth, supporting the hypothesis that GH treatment increases the inotropic activity of myocardial fibers. In conclusion, GH treatment enhances cardiac function, increases cardiac mass, and reverses diastolic abnormalities in adults with hypopituitarism and GHD. However, long term studies are required to demonstrate that GH replacement therapy reduces cardiac death rate in these patients.

Partial recovery of insulin secretion and action after combined insulin-sulfonylurea treatment in type 2 (non-insulin-dependent) diabetic patients with secondary failure to oral agents.

Metabolic control, insulin secretion and insulin action were evaluated in seven Type 2 (non-insulin-dependent) diabetic patients with secondary failure to oral antidiabetic agents before and after two months of combined therapy with supper-time insulin (Ultratard: 0.4 U/kg body weight/day) plus premeal glibenclamide (15 mg/day). Metabolic control was assessed by 24 h plasma glucose, NEFA, and substrate (lactate, alanine, glycerol, ketone bodies) profile. Insulin secretion was evaluated by glucagon stimulation of C-peptide secretion, hyperglycaemic clamp (+ 7 mmol/l) and 24 h free-insulin and C-peptide profiles. The repeat studies, after two months of combined therapy, were performed at least 72 h after supper-time insulin withdrawal. Combining insulin and sulfonylurea agents resulted in a reduction in fasting plasma glucose (12.9 +/- 7 vs 10.4 +/- 1.2 mmol/l; p less than 0.05) and hepatic glucose production (13.9 +/- 1.1 vs 11.1 +/- 1.1 mumol.kg-1.min-1; p less than 0.05). Mean 24 h plasma glucose was also lower (13.7 +/- 1.2 vs 11.1 +/- 1.4 mmol/l; p less than 0.05). Decrements in fasting plasma glucose and mean 24 h profile were correlated (r = 0.90; p less than 0.01). HbA1c also improved (11.8 +/- 0.8 vs 8.9 +/- 0.5%; p less than 0.05). Twenty-four hour profile for NEFA, glycerol, and ketone bodies was lower after treatment, while no difference occurred in the blood lactate and alanine profile. Insulin secretion in response to glucagon (C-peptide = +0.53 +/- 0.07 vs +0.43 +/- 0.07 pmol/ml) and hyperglycaemia (freeinsulin = 13.1 +/- 2.0 vs 12.3 +/- 2.2 mU/l) did not change.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of maternal metabolic control and insulin antibodies on neonatal complications and B cell function in infants of diabetic mothers.

Circulating insulin antibodies at birth and the degree of maternal metabolic control were measured in 68 infants of insulin-treated diabetic mothers. Their correlation with neonatal B cell function and with the clinical features of the infants was evaluated in order to better understand their influence on fetal outcome. Maternal metabolic control was assessed on the basis of blood glucose levels, glycosuria and the occurrence of hypoglycemia and/or ketonuria. All infants were clinically evaluated for gestational age, macrosomia, hypoglycemia, hyperbilirubinemia, hypocalcemia, and respiratory distress syndrome. Cord blood plasma glucose, C peptide, and IgG insulin antibodies were also measured. It was shown that poor maternal metabolic control was associated with a higher prevalence of fetal morbidity as well as with signs of B cell hyperfunction. Also the presence of circulating insulin antibodies correlated well with higher C peptide levels and with several neonatal complications. B cell hyperfunction, indicated by high C peptide levels in the infants of diabetic mothers, may possibly play a causal role in the pathogenesis of fetal morbidity. In conclusion, a good fetal outcome in insulin-treated diabetic pregnancies was associated with and may have depended upon: (1) good maternal metabolic control, and (2) absence or low levels of circulating insulin antibodies.

Blood glucose control and insulin secretion improved with combined therapy in type 2 diabetic patients with secondary failure to oral hypoglycaemic agents.

The influence of combined therapy using insulin and oral hypoglycaemic agents on blood glucose control and on insulin secretion in Type 2 diabetic patients with secondary failure to oral hypoglycaemic agents was evaluated. Type 2 diabetic patients (n = 180) (98 normal-weight, 82 over-weight), at least 3 years from diagnosis, and having poor blood glucose control on oral hypoglycaemic agents for at least 3 months (fasting plasma glucose greater than 10.0 mmol l-1) despite intensive efforts at improvement, were included in the study. A single daily insulin injection (human ultralente), at a dose of 0.22 +/- 0.07 U kg-1 d-1 in normal-weight and 0.33 +/- 0.10 U kg-1 d-1 in over-weight patients, was added to the previous dietary and drug treatment for 6 months. A progressive and significant (2p less than 0.001) reduction of the mean daily blood glucose was observed during the first 3 months of combined therapy (from 13.2 +/- 3.2 to 8.1 +/- 2.1 mmol l-1 in normal-weight and from 13.4 +/- 3.1 to 8.8 +/- 2.3 mmol l-1 in over-weight patients), with no further significant changes thereafter. A significant increase (2p less than 0.001) in the mean daily C-peptide concentration (from 0.50 +/- 0.30 to 0.71 +/- 0.29 nmol l-1 in normal-weight and from 0.78 +/- 0.36 to 1.00 +/- 0.41 nmol l-1 in over-weight patients) took place during combined therapy. No changes of body weight (+ 1.5 +/- 1.2 kg in normal-weight and + 1.0 +/- 1.0 kg in over-weight patients) were observed.

Reduction in insulin antibodies 42 months after transfer from porcine to human monocomponent insulins.

The present study was planned to evaluate if a longterm follow-up would show any modification of insulin antibodies in IDDs transferred from porcine to human monocomponent insulins. Nineteen IDDs, treated for more than one year with porcine monocomponent insulins, were transferred to the equivalent formulations of human insulin (Actrapid HM, Monotard HM); insulin antibodies, metabolic control, insulin dose, adverse drug reactions were evaluated during a 42-month follow-up. A reduction of IgG insulin antibodies was observed after 22 months of the follow-up and became significant (2p less than 0.05) at the 42nd month. No significant modification of metabolic control, insulin requirement, or hypoglycaemic episodes were recorded. No adverse events were reported.

Humoral immunity in diabetic pregnancy: interrelationships with maternal/neonatal complications and maternal metabolic control.

The presence of islet cell antibodies (ICA), complement fixing islet cell antibodies (CF-ICA), other organ-specific autoantibodies, insulin antibodies and two different types of immune complexes (AgAb) in diabetic pregnant women treated with insulin during pregnancy was investigated and compared with maternal metabolic control and with the course and outcome of pregnancy. One hundred and eighteen pregnant diabetic women were grouped according to type of diabetes: 56 were insulin-dependent diabetic patients who had been previously treated with insulin (Group 1); 23 were non-insulin-dependent diabetic patients who had previously received diet or oral treatment (Group 2); 39 had gestational diabetes (Group 3). 94 patients were subjected to regular check-ups during pregnancy and blood samples were taken during the last month of pregnancy (phase A); some were treated with standard preparations of insulin, the remainder with purified insulins. 24 patients were treated with purified insulins (a bovine and porcine mixture) on entering the study and blood samples were taken at regular intervals during pregnancy (phase B). ICA were detected in 12% of the patients in Group 1 and in 5% of those in Group 3. There was no significant variation in the titre during the gestational period. ICA were not detected in the patients in Group 2. No CF-ICA were found in any of the patients. The positivity of the other organ-specific autoantibodies was similar to that the normal control group. Insulin antibodies were found in concentrations of 67%, 73% and 25% in Groups 1,2 and 3 respectively during the last month of pregnancy.(ABSTRACT TRUNCATED AT 250 WORDS)

Semisynthetic human insulin: biologic and immunologic activity in newly treated diabetic subjects during a six-month follow-up.

Biologic and immunogenic activities of semisynthetic human monocomponent insulins were examined in insulin-dependent diabetic patients (group 1). Patients treated with porcine monocomponent (group 2) and conventional (group 3) insulins were studied for control purposes. The patients were examined before the beginning of insulin treatment and for a 6-mo follow-up period. The data collected during the study show that insulin antibody levels were significantly lower in group 1 than in groups 2 and 3. Furthermore, the prevalence of immune complexes assays with the C1q solid phase technique failed to reveal any differences between the three groups. When the conglutinin binding test was used, the prevalence of immune complexes showed a slight but not significant reduction in group 1 and a significant increase in group 3. The metabolic control was similar in the three groups during follow-up and the insulin requirement was lower, but not significantly, in group 1 than in groups 2 and 3. These data suggest that with human monocomponent insulins equivalent glycemic control may be achieved at similar doses than those required with porcine monocomponent insulins. Furthermore, human insulin is the least immunogenic of the present available insulins.

Lymphocyte subsets and immune complexes in long-standing diabetic patients: relation with the presence of microangiopathy.

Subsets of peripheral T lymphocytes by monoclonal antibodies and circulating immune complexes by two different methods were evaluated in 36 long-standing diabetic patients, 19 Type 1 (insulin dependent) and 17 Type 2 (non-insulin dependent). In all patients the presence of microangiopathy was assessed by retinal fluoroangiography, albuminuria and creatinine clearance. In patients with Type 1 diabetes a significant decrease of total T and of T cells with helper phenotype (T4), together with an increase of T cells with suppressor/cytotoxic phenotype (T8), were observed. No significant modifications in the percentage of T lymphocyte subsets were detected in patients with Type 2 diabetes. Immune complexes were found to be significantly increased in Type 1 compared with Type 2 diabetic patients. Patients with very high levels of T8+ cells did not have detectable immune complexes and had no evidence of microangiopathy. By contrast, patients with normal levels of these cells were found to have raised immune complexes and showed retinopathy of varying degree. The results of this study indicate that: (1) a relationship exists between cells with T8 phenotype, some immune complexes and the presence of microangiopathy; (2) the decrease of T4+ cells in Type 1 diabetics with long duration of disease may be responsible for the known susceptibility to infections in these patients.

The correlation between insulin antibodies and circulating immune complexes in diabetics with and without microangiopathy.

The relationship between immune complexes and insulin antibodies was evaluated in 237 insulin treated subjects with a duration of diabetes of more than 1 year. Ninety-seven diabetics were selected at random (group 1) whereas 140 according to the presence of diabetic microangiopathy (group 2). Immune complexes were evaluated by the solid phase C1q binding test in all patients and by conglutinin radioimmune assay in most of them. Insulin antibodies were determined by Christiansen's and Anderson's methods. Immune complexes as detected by the solid phase C1q method were found increased in group 1 and there was an inverse correlation between these complexes and insulin antibody levels. In group 2 patients with microangiopathy the amount of this kind of complex was significantly greater than in those without microvascular lesions and there was no correlation with insulin antibodies. Immune complexes as detected by conglutinin were found increased in group 2 patients and these were significantly correlated with the level of insulin antibodies. No increase in these immune complexes was found in patients with microangiopathy when compared with patients without microangiopathy. Insulin antibodies were not correlated with the presence of complications. Overall, immune complexes detected by C1q binding were significantly correlated with the presence of microangiopathy. In patients with high insulin antibody levels the complexes formed were not detected by C1q binding. The immune complexes detected by conglutinin are correlated with insulin antibodies, but not with the presence of microangiopathy.

Circulating immune complexes in diabetics: the influence of sex, age, duration of disease and type of treatment.

The influence of sex, age, duration of diabetes and type of antidiabetic treatment on soluble immune complexes levels was investigated in the sera of 276 randomly selected diabetics. Immune complexes were detected by the solid phase C1q binding test. The prevalence of immune complexes was significantly higher in insulin treated than in non-insulin treated diabetics. Within the insulin treated group, the prevalence in diabetics of 11-20 yr duration was significantly higher than in the remainder. No difference in immune complexes levels was found between males and females. The age of the patients did not have any correlation with the levels of immune complexes. These findings suggest that some of the immune complexes detected in randomly selected diabetics are related to insulin treatment, reflecting either differences in the type of diabetes or the effects of heterologous insulin.

Aspects of humoral immunity in a prospective study of Type I (insulin-dependent) diabetic subjects treated with insulins of different purity.

In 41 Type 1 (insulin-dependent) diabetic patients, islet cell antibodies, anti-insulin antibodies, and immune complexes measured by two different methods (the C1q solid phase assay and the conglutinin binding test) were studied at diagnosis, and the influence of treatment with insulins of different purity was investigated during the first year of treatment. Twenty subjects were treated with conventional insulins (group 1) while 21 were treated with monocomponent porcine insulins (group 2). The prevalence of islet cell antibodies significantly decreased during the 12-month study period in the 41 patients. From the first month anti-insulin antibodies were always significantly higher in group 1 than in group 2. At diagnosis the prevalence of both types of immune complexes in the 41 patients was higher than in normal subjects. The immune complexes measured by the C1q solid phase method showed a significant and progressive reduction during the follow-up period, whereas the immune complexes assayed by conglutinin showed no significant variation in the same period. The presence of C1q immune complexes was found to correlate with the occurrence of islet cell antibodies both at diagnosis and during the follow-up period. The presence of conglutinin immune complexes, on the other hand, tended to parallel the increase of anti-insulin antibody levels.

Monoclonal antibodies defined abnormalities of T-lymphocytes in type I (insulin-dependent) diabetes.

Peripheral T-lymphocytes subsets have been investigated in 36 patients with type I (insulin-dependent) diabetes of varying duration, 18 patients with type II (non-insulin-dependent) diabetes, and in 23 healthy subjects, using six different monoclonal antibodies. At the time of diagnosis of type I diabetes, there was evidence of an increase in cytotoxic T-lymphocytes, a decrease in suppressor T-lymphocytes, but a normal proportion of helper/inducer T-lymphocytes. In six of seven newly diagnosed cases studied, there was evidence of an increased number of activated T cells. An increase in activated T-cells was also found in 5 of 10 genetically susceptible islet cell antibody positive unaffected siblings in type I diabetic probands. In type I diabetes of long standing, the total T-cell population was decreased, largely due to a marked decrease in helper/inducer T-lymphocytes. Type II diabetic patients showed no abnormalities in T-lymphocyte subsets, making it unlikely that hyperglycemia was responsible for the changes observed. These results suggest that an imbalance of T-lymphocyte regulation is an important feature of type I diabetes and lend support for an immunologic role in its early pathogenesis.

Circulating immune complexes in diabetics with severe microangiopathy: evaluation by two different methods.

An investigation on circulating immune complexes (AgAb) was carried out in 80 diabetics with severe microangiopathy and in 71 diabetics without microvascular lesions. The duration of the disease, the type of diabetes, the type of treatment and the main localization of microangiopathy (retinopathy and nephropathy) were taken into account. AgAb were detected by two different methods: the solid phase Clq binding test (ClqSP) and the conglutinin binding test (KgBt). AgAb detected by ClqSP were increased both in prevalence and quantities in diabetics with severe microangiopathy regardless of the duration of the disease and the type of diabetes. Long standing diabetics without microangiopathy had similar prevalence of AgAb as normal controls. The presence of AGAb was not in correlation with the type of treatment and was similar in diabetics with retinopathy and in those with nephropathy. When AgAb were detected by KgBt, they were found with higher prevalence in diabetics than in normal controls but no correlation with microangiopathy was observed. AgAb, detected by KgBt, were higher in long standing type I diabetics. Since the two methods detect different AgAb it is concluded that AgAb present in diabetics seem to be heterogenous and part of them are related to the presence of microangiopathy.

Impaired phagocytic function and increased immune complexes in diabetics with severe microangiopathy.

An increase in circulating immune complexes (AgAb) of medium size has been observed in diabetics with late complications. This increase may be related either to an increased formation or reduced clearance. Alternatively, both mechanisms may be involved. As medium-sized AgAb determined by the C1q solid phase method are mainly removed from circulation by the fixed phagocytes of the reticulo-endothelial system, we investigated the function of these cells using a colloid clearance test in diabetics with various degrees of microangiopathy. Microaggregated iodinated human serum albumin was injected into 30 diabetic volunteers with severe (group 1), moderate (group 2), and absent (group 3) microangiopathy, and into 40 normal volunteers. The colloid clearance was significantly reduced in diabetics with severe microangiopathy in comparison with patients who had no sign of microangiopathy, or with normal subjects. A significant correlation was found between reduced colloid clearance and increased levels of circulating AgAb determined by C1q solid phase method. Results of this study suggest that the increase in circulating AgAb observed in patients with severe microangiopathy may result from an impaired function of mixed phagocytes.

New evidence of circulating immune complexes in Crohn's disease using two sensitive methods.

Circulating immune complexes (AgAb) were studied in 183 serum samples from 119 patients with Crohn's Disease. AgAb were studied by the solid phase C1q binding test in all sera and also by the conglutinin binding assay in 161 sera. A significantly higher prevalence of circulating AgAb was observed in Crohn's disease patients in comparison with the control population. About one half of the sera were AgAb positive when the results of both tests were combined whereas AgAb were found in about one third of the sera by each individual method. Complexes revealed by the C1q-SP appeared to be related to the disease activity and to the occurrence of complications. Such a correlation was not observed as far as conglutinin results are concerned. Data emerging from the present investigation indicate that circulating AgAb may be present in Crohn's disease and suggest that the AgAb material is heterogeneous. They also suggest the possibility that AgAb represent a secondary phenomenon.