Pilot study on omega-3 fatty acids in type I diabetes mellitus.

Patients with diabetes mellitus are prone to develop vascular complications. Because omega-3 polyunsaturated fatty acid (omega 3FA) intake has a potential protective effect on cardiovascular disease, we studied the influence of omega 3FA supplementation (5.4 g eicosapentaenoic acid and 2.3 g docosahexaenoic acid daily) for 4 wk in 13 well-controlled type I (insulin-dependent) diabetic subjects on a vascular risk profile. Each subject served as his/her own control in a pre- and post-omega 3FA-intake phase. In plasma and platelets, phospholipids eicosapentaenoic acid and docosahexaenoic acid increased at the expense of arachidonic acid and linoleic acid. There was no significant change in blood pressure and glycosylated proteins. Only small changes were noted in blood glucose levels and insulin dose. Side effects were not noted. Triglycerides decreased significantly in the first 14 days, and total cholesterol increased slightly, probably because of an elevation of high-density lipoprotein cholesterol, although low-density lipoprotein cholesterol remained unchanged. Platelet aggregation induced by low doses of ADP and collagen, which was higher in diabetic than nondiabetic subjects, decreased during omega 3FA intake to levels of healthy control subjects. Thromboxane production after ADP- and collagen-induced platelet aggregation decreased significantly. Thromboxane liberation during clotting of whole blood and urinary excretion of thromboxane were markedly lowered during omega 3FA supplementation. The results show that even short-term intake of omega 3FAs leads to beneficial changes of vascular risk factors without significant changes in glucose homeostasis.

Fate of late complications in type I diabetic patients after successful pancreas-kidney transplantation.

The success rate of pancreas transplantation allows us to study in more detail the potential beneficial effects of normoglycemia on secondary complications in diabetes mellitus. We report a prospective follow-up (mean 26 mo) of metabolic control, neuropathy, retinopathy, and peripheral microcirculation in 31 patients with type I (insulin-dependent) diabetes (mean age 33 +/- 1 yr; mean duration of diabetes 21 +/- 1 yr) after combined kidney and segmental pancreas grafting. All patients had normal HbA1 levels. Glucose tolerance (GT), insulin, C-peptide, and glucagon were normal in 22 patients, and impaired oral GT with reduced insulin secretory capacity was seen in 9 patients. During follow-up, there was no deterioration of GT and insulin release. Vascular risk factors, e.g., hypertension, cholesterol, and triglycerides, decreased after grafting. Autonomic neuropathy improved clinically, and R-R variation increased significantly in 3 of 18 patients. Peripheral neuropathy improved clinically in 46% of patients and did not deteriorate in the others. Motor nerve conduction velocity increased greater than 20% in 8, less than 20% in 12, and was unchanged in 8 of 28 recipients. Most of the patients (n = 30) had pretransplant laser treatment of their advanced retinopathy. Posttransplant visual acuity improved at least more than one line in 56%, stabilized in 32%, and deteriorated in 12% of patients. Patients with functioning grafts for greater than 1 yr had no further deterioration of visual acuity. Vitreous hemorrhage frequency and severity dropped markedly from pretransplant (from 69 to 24%) 10 mo after grafting. Retinal morphology remained stable in all eyes except two.(ABSTRACT TRUNCATED AT 250 WORDS)

Crossover study with human insulin (recombinant DNA) in type I diabetic subjects.

The activity of three combinations of regular and NPH human insulin (recombinant DNA) has been compared to that of an intermediate-acting pork insulin in a crossover study in type I diabetic subjects. After a prephase, the patients injected each insulin subcutaneously for 1 wk in different order. During the 5-wk period, daily glucose profiles were self-monitored, except at the end of each week, when blood was sampled for the determination of glucose, HbA1, glycosylated albumin, C-peptide, glucagon, and routine laboratory parameters. Fasting as well as mean daily glucose and mean amplitude of glucose excursions were similar during the treatment with pork and the various human insulin preparations. There was also no significant difference in C-peptide, glucagon, HbA1 or the routine laboratory parameters with each insulin tested. Glycosylated albumin, however, was significantly lower during the test period with intermediate-acting pork insulin and human insulin (25:75 regular:NPH), when compared with the prephase. We conclude that in type I diabetic subjects human insulin in special galenic preparations shows very similar metabolic activity to pork insulin.

The stimulatory and inhibitory function of theophylline on amino acid-induced insulin release: studies with the perfused rat pancreas.

The effects of 5 mM theophylline on L-phenylalanine, L-alanine, and L-leucine-induced insulin secretion were studied using the isolated perfused rat pancreas, varying the sequence of the stimuli. Theophylline in the absence or presence of 3 mM D-glucose caused a small amount of insulin release with a slow onset and a slight and steady increase. Theophylline had no effect on phenylalanine (5, 10, or 20 mM)-induced insulin release independent of the sequence of stimuli. Alanine (20 mM), in the absence of glucose, had no significant insulin stimulatory action. When theophylline was added during the alanine perfusion only a small insulin release, comparable to that given by theophylline alone, could be observed. However, superimposing alanine on a theophylline perfusion led to a potentiation of insulin release. The leucine-induced insulin secretion was significantly altered by the addition of theophylline. At a low concentration of leucine (5 mM) theophylline caused potentiation of leucine-induced insulin secretion. At 10 and 20 mM leucine, theophylline led to a rapid concentration-dependent inhibitory period, followed by a potentiation in the case of 10 mM leucine, and by a restoration of the secretion rate at 20 mM leucine which did not exceed the secretion rate of 20 mM leucine alone. Subsequent removal of theophylline caused a marked "off effect." When 5 or 20 mM leucine was superimposed on a theophylline perfusion, a marked dose-dependent potentiation of the biphasic leucine-induced insulin release and no inhibitory phase could be observed. From these data it must be concluded that the effect of theophylline on the insulin secretory reposure of the beta cell to theophylline and the stimulus. Possible explanations for these phenomena are discussed.

Plasmatic factors of haemostasis remain essentially unchanged except for PAI activity during n-3 fatty acid intake in type I diabetes mellitus.

Diabetic patients are prone to develop vascular complications. Increased procoagulatory factors and a reduced fibrinolytic potential are considered as thrombogenic risk factors, although controversy remains. In epidemiological and dietary intervention studies fish or fish oil, rich in the two n-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have demonstrated a potential to reduce cardiovascular disease. We compared the plasmatic coagulatory and fibrinolytic profile of 13 near normoglycaemic type I diabetics almost free of cardiovascular disease with healthy volunteers, matched for age and sex. Except for fibrinogen levels and tPA activity being elevated and soluble fibrin and fibrinopeptide A being reduced, no differences could be discerned between type I diabetics and controls in all investigated plasmatic parameters. In a dietary intervention study we investigated the effects of 5.4 g EPA and 2.7 g DHA per day during and after a 4-week dietary supplementation in the diabetic patients. The factors, inhibitors and activation products of coagulation and fibrinolysis measured were at best transiently affected by the diet. Only plasminogen activator inhibitory activity in plasma significantly increased during the dietary supplementation and returned to prediet values after cessation of n-3 fatty acids. Changes in PAI activity were negatively correlated to changes in serum triglycerides. We conclude that well adjusted type I diabetics show an almost unchanged haemostatic profile compared to matched healthy controls. A dietary intervention with n-3 fatty acids in these patients does not affect the plasmatic haemostatic pattern except for an increase in PAI activity.

[Differences in application and granting benefits for severely disabled patients before and after introduction of new benefits within the scope of the public health reform law]. / Unterschiede in der Beantragung und Gewährung von Leistungen für Schwerpflegebedürftige vor und nach Einführung neuer Leistungen im Rahmen des Gesundheitsreformgesetzes.

Constituting part of the health reform in Germany ("Bundesgesundheits-Reformgesetz"), an extension of health insurance benefits for severely disabled persons was introduced in 1991. The assessment of eligibility for benefits is based on standardised medical examinations. Examinations performed in the state of Baden-Württemberg in 1990 (n = 6401) were compared with a 20% random sample of those performed in 1991 (n = 7563) in order to analyse eventual changes in acceptance rates of applications. Acceptance rates decreased from 87.9% in 1990 to 70.8% in 1991. The difference could not be explained by differences in age, sex, medical diagnosis or dependence on help in daily activities. This suggests that acceptance criteria were less restrictive before introduction of the extension of benefits.

The prostaglandins system and insulin release. Studies with the isolated perfused rat pancreas.

Using the isolated perfused rat pancreas PGE2 (1 MUM and 10 muM) had no effect on basal or glucose (10 and 20 mM)-induced insulin release (IR). PGF2 alpha stimulated basal IR at 1 muM and inhibited IR at 10 muM. The glucose-induced IR was unaffected by this PG. Furosemide (5 and 10 mM) led to a monophastic IR at low glucose (glu) and to a potentiation of IR at high glu. Only high indomethacin (Indo) (50 microgram/ml) inhibited glu-induced IR. The stimulatory effect of furosemide on IR could not be inhibited by indomethacin. However mepacrine (0.1 mM) abolished the furosemide effect. Also glu-induced IR was inhibited by mepacrine. Acetylsalicylic acid (30 mg/100 ml) had no significant influence on glu-induced IR. These findings provide evidence that phospholipase activation rather than increased PG synthesis might primarily be involved in the secretory process of insulin.

[Effect of caerulein on blood glucose, serum insulin, glucagon, prolactin and growth hormone before and after oral glucose load in healthy volunteers and diabetic patients (author's transl)]. / Wirkung von Caerulein auf Blutglukose, Seruminsulin, Glucagon, Prolaktin und Wachstumshormon vor und während einer oralen Glukosebelastung bei Gesunden und Diabetikern.

Eleven healthy volunteers, five type I diabetics, and one type II diabetic man were examined. After an overnight fast caerulein (20 ng/kg) was injected intravenously and 60 min later an oral glucose tolerance test was performed with 100 g glucose in the normals and 25 g glucose in the diabetics. Blood pressure, pulse rate, blood glucose, serum insulin, glucagon, prolactin and growth hormone values were measured during the whole period of 240 min and compared with the same parameters in control tests in the same persons without caerulein application. None of the measured parameters were significantly influenced by caerulein. It is therefore concluded that in contrast to the stimulation of the exocrine pancreas functions of the endocrine pancreas, the pituitary gland and glucose tolerance are unchanged after caerulein.

Sulphydryl requirement for insulin release from the perfused pancreas. Studies with ethacrynic acid and dithiothreitol.

Using the isolated, perfused rat pancreas the importance of sulphydryl groups for the secretory process of insulin was investigated. It was found that ethacrynic acid (EA, 0.075-0.6 mmol/1) caused a dose-dependent, monophasic insulin release. Addition of EA to a glucose-stimulated (20 mmol/1) pancreas led to a sudden increase in hormone release, followed by a dose-dependent inhibition of release, which was not reversible after removal of EA. The same phenomenon was seen in the presence of 20 mmol/1 leucine. Dithiothreitol (DTT, 0.1 and 1 mmol/1) had no effect on basal insulin secretion. Added to a glucose-stimulated pancreas DTT (1 mmol/1) caused a reversible inhibition of insulin release. The persistent inhibitory action of EA on glucose-induced insulin release could be reversed by simultaneous perfusion of EA and DTT. Sequential exposure of a glucose-stimulated pancreas to EA and DTT led to a rapid release of insulin, due to DTT; however, the EA-induced inhibition of insulin secretion could not be prevented. Two kinds of thiol groups in the plasma membrane and in the beta cell might be responsible for the various kinetics of insulin release induced by EA and DTT.

Immunoturbidimetric assay for the determination of microalbuminuria using the Hitachi analyser.

A sensitive and specific immunoturbidimetric method is described for the determination of low concentrations of urinary albumin using a Hitachi 704 or 705 analyser. The sensitivity was 1 mg/l and the precision attained was good (CV 15%, 7% and 6% for low, medium and higher albumin concentrations). The assay was used to determine urinary albumin excretion rates in healthy controls (less than 15 micrograms/min) and in type I diabetics. Since microalbuminuria (30-200 micrograms/min) seems to be a good predictor for the development of diabetic nephropathy and other late diabetic complications, this assay is suitable for the necessary screening and follow-up of diabetic nephropathy. In contrast to RIA methods, no radioactive tracers are needed.

Counterregulatory hormone release after human and porcine insulin in healthy subjects and patients with pituitary disorders.

Human and porcine insulin were administered intravenously to a group of healthy volunteers in two different doses (0.075 IU/kg body weight and 0.12 IU/kg body weight) and to two groups of randomly selected patients with pituitary disorders in a dose adapted to their individual glucose tolerance (0.12-0.17 IU/kg body weight for porcine and 0.15-0.18 IU/kg body weight for human insulin). The blood glucose and potassium lowering effect, the feedback regulation of endogenous insulin release, and the liberation of the counterregulatory hormones glucagon, cortisol, adrenocorticotropic hormone (ACTH), prolactin (hPRL), human growth hormone (hGH), and catecholamines were measured before and after injection of human or porcine insulin. The maximal effect, the area under the concentration-time curve, the percentage effect, and the increase above baseline for the two doses of insulin and the two types of insulin were compared. There were no significant differences in the calculated parameters between the two insulin types at the same doses except with prolactin. At 0.075 IU/kg human insulin induced significantly less prolactin release than porcine insulin. Comparing the two doses of the same insulin serum insulin levels, blood glucose, glucagon, norepinephrine, and prolactin were lower at the low dose of each insulin. In addition ACTH and epinephrine were also lower after human insulin at 0.075 IU/kg. The subjective signs of hypoglycemia were less pronounced after human insulin. It is concluded that the biological effects of human insulin are comparable to porcine insulin although prolactin release is significantly reduced after human insulin. If this difference is an indication of different receptor sensitivities for human and porcine insulin in the central nervous system and if the diminished signs of hypoglycemia are a consequence of this, then further studies are required.

Increased thromboplastic potential in diabetes: a multifactorial phenomenon.

Coagulation parameters, platelet aggregation, and thromboxane production as well as metabolic parameters were measured in 31 diabetic patients, 12 without and 19 with clinically manifest late complications, and in 14 healthy control subjects. Spontaneous in vitro aggregation as well as ADP, collagen, and arachidonic acid induced aggregation were higher in both groups of diabetic patients, without an increase in thromboxane B2 production. In diabetic patients with late complications an increase in fibrinogen, fibrinogen cyanogen bromide peptide, factor VIII related antigen, C1-esterase inhibitor, and antithrombin III was observed in comparison to healthy subjects. Fibrinogen, C1-esterase inhibitor, and factor VIII related antigen were already elevated in diabetic patients without clinically manifest late vascular complications. No strict correlations were found between serum glucose, glycosylated hemoglobin, and glycosylated albumin, on the one hand, and coagulation promoting or inhibiting factors, aggregation or thromboxane B2 production, on the other, in either control or diabetic subjects. Also no correlations existed between the coagulation parameters and the aggregation results. In vitro incubation of pooled normal plasma with different glucose concentrations had no influence on the methods by which the coagulation parameters were measured. These data indicate that rather early in the diabetic state many changes take place in different phases of the thrombostatic process, all resulting in an increased hemostatic diathesis.

Hormonal profile and glucose tolerance in late pregnancy and postpartum.

Oral glucose tolerance, plasma insulin and basal levels of glucagon, hGH, hPRL, hPL, TSH, T4, T3, thyroxine-binding globulin (TBG), cortisol, corticosteroid-binding globulin (CBG) and estriol were measured in 23 normal pregnant women in late gestation (31 +/- 0.4 weeks of pregnancy). Twelve of these subjects could be re-examined 14 +/- 2 weeks postpartum. Blood glucose was lower basal and after glucose load (100 g) in the pregnant group. Fasting plasma insulin and glucose-induced insulin release were higher in pregnancy. The insulinogenic index and the beta cell response were significantly greater antepartum, while peripheral insulin activity was unchanged. The insulin:glucagon ratio as well as TSH and hGH showed no significant differences between ante- and postpartum values. However, T4, T3, TBG, cortisol, CBG, estriol, hPRL and hPL were significantly higher during gestation than after delivery. T4:TBG and T3:TBG ratios were much lower antepartum, while the cortisol:CBG ratio was comparable ante- and postpartum. To our knowledge this is the first report in which such an extensive hormonal and metabolic analysis was performed in the same women ante- and postpartum. It could be shown that glucose tolerance is not worsened during pregnancy in healthy subjects. The higher gestational insulin values are discussed with respect to the various significant hormonal changes.

Follow-up study of sensory-motor polyneuropathy in type 1 (insulin-dependent) diabetic subjects after simultaneous pancreas and kidney transplantation and after graft rejection.

The influence of successful simultaneous pancreas and kidney transplantation on peripheral polyneuropathy was investigated in 53 patients for a mean observation period of 40.3 months. Seventeen patients were followed-up for more than 3 years. Symptoms and signs were assessed every 6 months using a standard questionnaire, neurological examination and measurement of sensory and motor nerve conduction velocities. While symptoms of polyneuropathy improved (pain, paraesthesia, cramps, restless-legs) and nerve conduction velocity increased, there was no change of clinical signs (sensation, muscle-force, tendon-reflexes). Following kidney-graft-rejection there was a slight decrease of nerve conduction velocity during the first year, which was not statistically significant. Following pancreas-graft rejection there was no change of nerve conduction velocity during the first year. Comparing the maximum nerve conduction velocity of the patients with pancreas-graft-rejection to the nerve conduction velocities of these patients at the end of the study, there was a statistically significant decrease of 6.5 m/s. In conclusion, we believe that strict normalization of glucose metabolism alters the progressive course of diabetic polyneuropathy. It may be stabilized or partly reversed after successful grafting even in long-term diabetic patients.