Fear of hypoglycaemia in adults with Type 1 diabetes.

AIMS: The aim of this study was to examine the fear of hypoglycaemia and its association with demographic and disease-specific variables in a large and unselective population of adult patients with Type 1 diabetes. METHODS: Questionnaires were sent by post to all patients with Type 1 diabetes who were identified in the local diabetes registries of two hospitals in Stockholm, Sweden (n=1387). Fear of hypoglycaemia was measured using the Swedish Hypoglycaemia Fear Survey, the Worry subscale and the Aloneness subscale. Demographic variables and disease-specific factors were collected from patients' self reports and medical records. Univariate analysis and multiple stepwise linear regression analysis were used in the statistical analyses of the data. RESULTS: Seven hundred and sixty-four (55%) patients participated in the study (mean age 43.3 years and mean HbA(1c) 7.0%, normal <5.0%). The Hypoglycaemia Fear Survey - Worry subscale was significantly associated with frequency of severe hypoglycaemia, number of symptoms during mild hypoglycaemia, gender, hypoglycaemic symptoms during hyperglycaemia and hypoglycaemic unawareness. The Hypoglycaemia Fear Survey - Aloneness subscale was significantly associated with frequency of severe hypoglycaemia, number of symptoms during mild hypoglycaemia, gender, frequency of mild hypoglycaemia, HbA(1c) , hypoglycaemic unawareness and visits to the emergency room because of severe hypoglycaemia. Fear of hypoglycaemia proved to be more prevalent in females and indicated a different pattern between genders in relation to factors associated with fear of hypoglycaemia. CONCLUSIONS: This study identifies the frequency of severe hypoglycaemia as the most important factor associated with fear of hypoglycaemia. Moreover, for the first time, we document gender differences in fear of hypoglycaemia, suggesting that females are more affected by fear of hypoglycaemia than men.

Dissociated incretin response to oral glucose at 1 year after restrictive vs. malabsorptive bariatric surgery.

AIM: Compare the response to oral glucose of the two incretin hormones, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) at 1 year after restrictive vs. malabsorptive bariatric surgery. METHODS: Vertical banded gastroplasty (VBG, n = 7) or jejunoileal bypass (JIB, n = 5) was performed in 12 women, aged 26-39 years, with severe obesity [body mass index (BMI) 46.6 +/- 2.3 kg/m(2)]. After 1 year, 75 g glucose was administered and plasma levels of glucose, insulin, GIP and GLP-1 were determined regularly during the following 2 h. RESULTS: At 1 year after operation, reduction in body weight, actual body weight, fasting glucose or insulin, or the glucose and insulin responses to oral glucose did not differ significantly between the groups. Similarly, fasting GIP and GLP-1 levels did not differ significantly between the groups. In contrast, the GIP and GLP-1 responses to oral glucose were different between the groups in a dissociated pattern. Thus, AUC(GIP) was significantly higher after VBG than after JIB (53 +/- 8 vs. 26 +/- 6 pmol/l/min, p = 0.003). In contrast, AUC(GLP-1) was significantly higher after JIB than after VBG (49 +/- 5 vs. 20 +/- 3 pmol/l/min, p = 0.007). CONCLUSIONS: We conclude that at 1 year after bariatric surgery, the two incretins show dissociated responses in that the GIP secretion is higher after VBG whereas GLP-1 secretion is higher after JIB. This dissociated incretin response is independent from reduction in body weight, glucose tolerance or insulin secretion.

Can glycaemic variability, as calculated from blood glucose self-monitoring, predict the development of complications in type 1 diabetes over a decade?

AIMS: Is glycaemic variability an independent risk factor for the development of microvascular complications in addition to average glycaemia, as assessed by glycated haemoglobin (HbA(1c))? In this study, an 11-year follow-up was carried out in patients with type 1 diabetes. The standard deviation of blood glucose (SDBG) concentration, an index of glycaemic variability, was calculated from self-monitored blood glucose data at baseline. METHODS: A total of 100 patients were randomly selected from 442 consecutive type 1 diabetic patients attending our outpatients clinic. SDBG was calculated from 70 measurements taken over a period of four weeks. Onset and progression of micro- and macrovascular complications were recorded over the 11-year follow-up. RESULTS: As expected, the prevalence of complications increased over time. Statistical analyses showed that HbA(1c) was an independent predictor of the incidence (P=0.004) and prevalence (P=0.01) of nephropathy. SDBG was found to be a predictor of the prevalence of peripheral neuropathy (P=0.03), and showed borderline significance in predicting the incidence of peripheral neuropathy (P=0.07). SDBG was also a highly significant predictor of hypoglycaemic unawareness (P=0.001). CONCLUSIONS: We conclude that variability of blood glucose may be important in the development of peripheral neuropathy in patients with type 1 diabetes, and that the nervous system may be particularly vulnerable to glycaemic variability.

Immediate and time-dependent effects of glucose on insulin release from rat pancreatic tissue. Evidence for different mechanisms of action.

Glucose-induced insulin secretion is enhanced by a preceeding glucose stimulus. The characteristics of this action of glucose were investigated in perfused pancreas and collagenase-isolated islets of Langerhans. A 20- to 30-min pulse of 27.7 mM glucose enhanced both the first and second phase of insulin release in response to a second glucose stimulus by 76-201%. This enhancement was apparent as an augmented maximal insulin release response to glucose. The effect of priming with glucose was seen irrespective of whether the pancreatic tissue was obtained from fed or fasted rats. Separating the two pulses of hexose by a 60-min time interval of exposure to 3.3 mM glucose did not abolish the potentiation of the second pulse. Omission of Ca(++) as well as the inclusion of somatostatin or mannoheptulose during the first pulse abolished insulin secretion during this time period; however, only the inclusion of mannoheptulose deleted the potentiation of the second pulse. d-Glyceraldehyde, but not pyruvate, d-galactose, or 3-isobutyl-1-methylxanthine, could substitute for glucose in inducing potentiation. In islets labeled with [2-(3)H]adenine, the [(3)H]cyclic AMP response to glucose was increased by 35% when measured after 1 min, but was increased only marginally after 2-10 min of stimulation with a second pulse of glucose. The production of (3)H(2)O from glucose was not affected by glucose priming. It is concluded that (a) the induction of the glucose-induced, time-dependent potentiation described here is dependent on glucose metabolism but not on stimulation of cyclic AMP, calcium fluxes, or insulin release per se; (b) the mechanisms that mediate the pancreatic "memory" for glucose are unknown but do not seem to involve to a major extent an increased activity of the adenylate cyclase-cyclic AMP system of the beta-cell; (c) the evidence presented supports the hypothesis of a dual role of glucose for insulin release.

Glucose memory of pancreatic B and A2 cells: evidence for common time-dependent actions of glucose on insulin and glucagon secretion in the perfused rat pancreas.

The influence of previous exposure to glucose on the subsequent B- and A(2)-cell secretory responses to arginine was investigated in the perfused pancreas of the rat. Arginine (8 mM) was administered in two brief (9 min) pulses separated by a period of 66 min. In pancreata from 18-h-fasted animals the two pulses of arginine elicited biphasic glucagon secretory responses, while stimulation of insulin release was barely detectable. When 27.7 mM glucose was administered for 30 min during the intervening period up to 20 min before the second pulse of arginine, the glucagon response to arginine was diminished by 55% while the insulin release was markedly increased in comparison with the first pulse. 8.3 mM glucose, when administered before the second pulse of arginine, exerted effects that were smaller but otherwise similar to those of 27.7 mM glucose.The inclusion of 3.9 mM glucose during the stimulation periods with arginine decreased the glucagon and greatly increased the insulin secretory response. Under these conditions, previous exposure to 27.7 mM glucose inhibited the glucagon and enhanced the insulin response to the second stimulatory pulse of arginine to the same relative degree as when arginine was administered alone. Diazoxide (2 mM), when administered together with 27.7 mM glucose, almost completely inhibited insulin release induced by the presence of glucose, yet did not influence the modulation exerted by glucose on the subsequent insulin and glucagon secretory response to arginine. Conversely, these effects of the glucose pulse could not be reproduced by 1 mug/ml of porcine insulin. Previous exposure to glyceraldehyde (10 mM) mimicked the glucose effects.Also, in pancreata from fed rats, previous exposure to 27.7 mM glucose markedly inhibited subsequent arginine-induced glucagon secretion while the concomittant insulin response was enhanced.IT IS CONCLUDED THAT: (a) both A(2)- and B-cell responsiveness is modulated by a previous exposure to glucose which produces opposite effects in the two cell types, (b) this action of glucose does not depend on its insulin-releasing capacity, and (c) instead, a "memory" of glucose is induced as a consequence of the metabolism of the sugar in the A(2) and B cells.

A morning dose of insulin glargine prevents nocturnal ketosis after postprandial interruption of continuous subcutaneous insulin infusion with insulin lispro.

AIM: The aim of this crossover trial was to evaluate the potential of partial substitution of basal insulin with glargine, administered once daily in the morning, to protect against nocturnal ketosis after postprandial interruption of continuous subcutaneous insulin infusion (CSII). METHODS: Seven patients with type 1 diabetes received 4 weeks of treatment with insulin lispro, administered by CSII, and 4 weeks of treatment with CSII and a partial basal replacement dose of insulin glargine administered in the morning. On day 28 of each treatment phase, patients were admitted to the research unit where dinner was served and their usual dinner insulin bolus dose given, after which CSII was discontinued at 7 pm. Plasma (p) beta-hydroxybutyrate and p glucose were measured every hour for 12 h thereafter. RESULTS: Plasma beta-hydroxybutyrate at 7 pm was 0.16+/-0.05 and 0.13+/-0.07 mmol/l with and without glargine, respectively, and increased to 0.17+/-0.10 and 0.60+/-0.3 mmol/l within 6 h (P=0.02). Plasma glucose increased without glargine, from 8.6+/-2.9 to 21.1+/-3.0 mmol/l (P=0.003), but did not rise significantly following glargine (13.6+/-4.7 vs. 12.6+/-5.6 mmol/l; P=0.65). CONCLUSIONS: Partial replacement with a morning dose of insulin glargine protects against the development of ketosis for as much as 12 h after postprandial interruption of CSII. This treatment strategy could, therefore, be useful for patients who are prone to ketosis but, for other reasons, are deemed suitable for CSII.

Minimal increases in glucagon levels enhance glucose production in man with partial hypoinsulinemia.

In man a small dose of somatostatin (50 micrograms/h) suppressed moderately basal insulin (5 microU/ml) and glucagon (40 pg/ml) levels. This resulted in a short-lasting hypoglycemia, which was then followed by marginal hyperglycemia throughout the experiment. The addition of a minimal dose of glucagon (0.50 ng/kg/min) to somatostatin normalized basal glucagon levels and resulted in a significant and sustained hyperglycemia. During the first 2 h, hyperglycemia was mainly due to increased glucose production, whereas later on it was maintained by decreased glucose uptake. We conclude that, in man moderately deprived of insulin, even a marginal change in glucagon level induces a long-lasting hyperglycemia.

Nocturnal differences in subcutaneous tissue glucose between forearm and abdominal sites during continuous glucose monitoring in normal subjects.

OBJECTIVE: A number of short-term studies using the continuous glucose monitoring system (CGMS) indicate that improved metabolic control can be observed in patients with type 1 diabetes when CGMS is applied in clinical practice. Data have also accumulated to suggest that spot measurements of glucose performed four times a day would not detect as much as 70% of all hypoglycaemic episodes registered by CGMS. When more frequent reference values were obtained however it was inferred that nighttime hypoglycaemia reported by CGMS may be spurious. As most assessments with CGMS have been utilizing abdominal subcutaneous tissue, we were interested to evaluate whether differences between blood glucose and sensor readings obtained from different sites exist. RESEARCH DESIGN AND METHODS: Two viscometric affinity glucose sensors, applicable to subcutaneous tissue of both forearm and abdomen, were inserted subcutaneously in 12 non-diabetic subjects. Sensors generated glucose data at 3 min intervals and venous blood glucose was determined in duplicates by HemoCue at 15-90 min intervals for 24 hours. Each subject consumed three carbohydrate-rich meals, performed an exercise test, and was observed during nocturnal bed-rest at the research center. RESULTS: The initial decrease of blood glucose during exercise was not fully detected by the sensors. Otherwise, no significant differences between sensor values and blood glucose were observed during day-time. During nocturnal bed-rest abdominal sensor values came approximately 20% lower than blood glucose (P<0.001) and forearm sensor readings. CONCLUSION: It is concluded that a difference between glucose values obtained from abdominal and forearm subcutaneous fat can be observed during nocturnal bed-rest in non-diabetics.

Psychosocial state of patients with IDDM prone to recurrent episodes of severe hypoglycemia.

OBJECTIVE: The aim of this study was to investigate the psychosocial situation in patients with insulin-dependent diabetes mellitus (IDDM) with recurrent attacks of severe hypoglycemia (SH). RESEARCH DESIGN AND METHODS: The study group consisted of 17 adult patients with SH and 17 patients matched to the study group with regard to sex, age, and duration of diabetes without severe attacks. The psychosocial situation was measured by means of self-rated questionnaires and an observer's rating scale. RESULTS: Parameters such as social support, life events, type A behavior, neuroticism, and vital exhaustion were not different, although a higher anxiety rating (P less than 0.05) and a lower rating of happiness (P less than 0.01) were found in the SH group. CONCLUSIONS: We conclude that the anxiety level is increased and that experienced happiness is decreased in patients prone to recurrent severe hypoglycemia.

Comparison of bedtime NPH or preprandial regular insulin combined with glibenclamide in secondary sulfonylurea failure.

OBJECTIVE: To compare the effect of bedtime NPH insulin or preprandial regular insulin combined with glibenclamide on metabolic control in non-insulin-dependent diabetes mellitus (NIDDM) patients with secondary failure to sulfonylurea therapy. RESEARCH DESIGN AND METHODS: Eighty NIDDM patients were randomized to treatment with either three preprandial doses of regular insulin (daytime group D) or a bedtime dose of NPH insulin (nocturnal insulinization, group N), both regimens being combined with 10.5 mg of glibenclamide. Metabolic profiles were obtained at 0, 6, 16 weeks. RESULTS: Glycemic control had improved significantly in both groups after 4 months. Fasting blood glucose was significantly lower compared with baseline in both groups. The mean change +/- SD in group D was -2.8 +/- 3.5 mmol/l and in group N -6.4 +/- 3.0 mmol/L, the reduction being more pronounced in group N compared with group D (P < 0.0001). HbA1c was lowered similarly, from 9.2 +/- 1.4 to 7.1 +/- 1.2% in group D (P < 0.0001) and from 9.1 to 1.1 to 7.5 +/- 1.5% in group N (P < 0.0001). The total daily insulin doses were similar, 29 +/- 11 U in group D and 26 +/- 9 U in group N, and the circulating insulin levels during daytime were higher in group D than in group N. Total serum cholesterol and triglycerides were similarly and significantly lowered compared with baseline in both groups. Weight gain was more pronounced in group D (3.4 +/- 0.3 kg) than in group N (1.9 +/- 1.9 kg; D vs. N, P < 0.002), and the change was inversely correlated with initial eight but not with the improvement in HbA1c. CONCLUSIONS: The two insulin regimens exert similar effect on glucose metabolism and serum lipids in NIDDM patients on combination therapy. Weight gain is more pronounced in patients given insulin during the daytime when preprandial doses of short-acting insulin are used.

Inhibitory effect of circulating insulin on glucagon secretion during hypoglycemia in type I diabetic patients.

OBJECTIVE: To clarify whether the circulating insulin level influences hormonal responses, glucagon secretion in particular, during hypoglycemia in patients with insulin-dependent (type I) diabetes. RESEARCH DESIGN AND METHODS: Nine type I diabetic patients were studied. During two separate experiments, hypoglycemia was induced by low-dose (244 pmol.kg-1.h-1) and high-dose (1034 pmol.kg-1.h-1) intravenous insulin infusions for 180 min in each case. The arterial blood glucose level was directly monitored every 1.5 min, and glucose was infused in the high-dose test to clamp the arterial blood glucose level to be identical as in the low-dose test. RESULTS: Despite the fact that the plasma insulin level was four times higher in the high-dose than in the low-dose test (740 +/- 50 vs. 180 +/- 14 pM), a close to identical arterial hypoglycemia of approximately 3.3 mM was obtained in the two experiments. During hypoglycemia, a significant rise of the plasma glucagon level was found only in the low-dose test (188 +/- 29 vs. 237 +/- 37 ng/L, P less than 0.05), and the incremental area under the glucagon curve was significantly greater in the low-dose than in the high-dose test (140 +/- 19 vs. -22.7 +/- 34 ng/L.h-1, P less than 0.005). The responses of plasma epinephrine, norepinephrine, growth hormone, pancreatic polypeptide, and somatostatin were similar in both tests and, consequently, were not significantly modified by the circulating insulin level. CONCLUSIONS: This study demonstrates that, in type I diabetic patients, the glucagon response to hypoglycemia is suppressed by a high level of circulating insulin within the physiological range. Our findings may help to explain the impairment of glucagon secretion during hypoglycemia frequently seen in these patients.

Oral glibenclamide suppresses glucagon secretion during insulin-induced hypoglycemia in patients with type 2 diabetes.

Intensifying pharmacological therapy in patients with type 2 diabetes increases the risk of hypoglycemia and often requires the simultaneous use of more than one agent. Combining insulin and sulfonylurea is an effective and frequently used therapy in such patients. However, sulfonylurea derivatives have been shown to affect the release of glucagon, indicating a possible effect of such therapy on hormonal counterregulation to hypoglycemia. Thirteen patients receiving combined therapy were studied on two occasions: 1) after a wash-out period of glibenclamide (-GLIB), and 2) after resuming combined treatment for 6 months (+GLIB). We performed nonstep-wise, hyperinsulinemic hypoglycemic clamps using a constant i.v. insulin infusion and clamping blood glucose at 2.7 mmol/L (48 mg/dL) for 60 min. C Peptide levels were significantly higher during + GLIB, but no significant differences were seen in peripheral plasma insulin levels (+GLIB mean +/- SD, 70 +/- 17 mU/L vs. -GLIB, 75 +/- 14; P = 0.26). Epinephrine responses were similar in the two tests, but when glibenclamide was present the glucagon response was smaller, both the peak value (P = 0.016) and the incremental area under the curve (P = 0.011) as well as the total area under the curve (P = 0.016). These results suggest that intraislet insulin secretion is of importance for the alpha-cell responsiveness to hypoglycemia in these patients.

A high concentration of circulating insulin suppresses the glucagon response to hypoglycemia in normal man.

In an attempt to clarify whether circulating insulin per se exerts an inhibitory effect on the hormonal responses to hypoglycemia, with special emphasis on glucagon secretion, nine healthy volunteers were exposed to low dose (244 pmol/kg.h) and high dose (1034 pmol/kg.h) iv insulin infusions for 3 h on two separate occasions. A close to identical arterial hypoglycemia of about 3.4 mmo/L was obtained in both tests by glucose clamping during the high dose test. The corresponding glucose concentration in the venous blood was significantly lower in the high dose test (2.5 +/- 0.1 vs. 3.0 +/- 0.1 mmol/L; P less than 0.01), while the plasma free insulin level was 4 times higher in the high dose test (897 +/- 50 vs. 208 +/- 14 pmol/L). Plasma glucagon was elevated in both experiments, but its rise was reduced during the high dose test after 1 h, yielding an incremental area under the glucagon curve that was significantly smaller than that obtained during the low dose test (213 +/- 70 vs. 348 +/- 81 ng/L.h; P less than 0.05). The plasma adrenaline, noradrenaline, GH, C-peptide, pancreatic polypeptide, and somatostatin profiles were similar in the two tests. We conclude that an inhibitory effect of circulating insulin on the glucagon response to hypoglycemia can be demonstrated in normal man during an infusion of insulin yielding a plasma concentration of about 900 pmol/L. The responses of other hormones studied are not significantly influenced by the circulating insulin level.

Circulating insulin inhibits glucagon secretion induced by arginine in type 1 diabetes.

OBJECTIVE: To evaluate if insulin has a suppressive effect on the glucagon secretion stimulated by arginine in type 1 diabetes. RESEARCH DESIGN AND METHODS: The alpha-cell response to an i.v. bolus of arginine (150mgkg(-1)) followed by an infusion of arginine (10mgkg(-1)min(-1)) was studied in random order during either low dose infusion (LDT) or high dose infusion (HDT) of insulin in ten patients with type 1 diabetes. The blood glucose level was clamped at an arterialized level of 5mmoll(-1) by a variable infusion of glucose. Venous C-peptide, glucagon, growth hormone, and insulin were analyzed. RESULTS: The mean plasma concentration of insulin was four times higher during the HDT. The C-peptide level did not differ between the LDT and the HDT. During the LDT in response to arginine the blood glucose level increased from 5.0 to 5.8mmol l(-1) although the glucose infusion was markedly reduced, while no change was seen during the HDT. A significantly smaller increase in the glucagon levels during the HDT was seen (area under the curve of 413+/-45 vs 466+/-44pgml(-1)h(-1), P=0.03) while the growth hormone levels were almost identical. CONCLUSION: This study demonstrates that a high level of circulating insulin exerts an inhibitory effect on the glucagon response to arginine in type 1 diabetes. Thus, the suppressive effect of insulin on the glucagon release from the alpha-cell seems to be general and not only dependent on stimulation by hypoglycemia.

Improved beta cell function after short-term treatment with diazoxide in obese subjects with type 2 diabetes.

OBJECTIVE: Our aim was to distinguish beneficial effects of B-cell rest from other effects of correction of hyperglycaemia. For this purpose we used diazoxide which reversibly blocks insulin secretion. MATERIAL AND METHODS: Eight obese (age 53 +/- 1 yr: BMI 33 +/- 2 kg/m2: 4 females) type 2 diabetic patients with poor metabolic control (HbA1c 8.7 +/- 0.9% ref.<5.2%) were studied twice after a randomly ordered treatment period of five days of intensive i.v. insulin treatment alone or i.v. insulin with peroral diazoxide (300 mg/day, divided into 3 doses). The glycaemic control was not altered between the two treatment periods. Insulin secretion was measured in response to i.v. glucose and arginine. RESULTS: Insulin infusion was used to achieve close to identical degrees of glycaemia during the two treatment periods. Previous treatment with diazoxide was associated with a moderate 1.9 +/- 0.6 fold rise in insulin response to intravenous glucose (p=0.04) and 1.6 +/- 0.4 fold increased glucose potentiation of arginine-induced insulin secretion (GPAIS) (p=0.04). Conversely, after insulin alone there was no response to i.v. glucose and no change in GPAIS. CONCLUSIONS: Short-term diazoxide treatment improved important parameters of B-cell function and these effects could be dissociated from confounding effects of changes in glycaemia. Consequently, the results indicate beneficial effects of B-cell rest.

Continuous intraperitoneal insulin infusion partly restores the glucagon response to hypoglycaemia in type 1 diabetic patients.

The glycaemic and hormonal responses to a hypoglycaemic event induced by an i.v. bolus of insulin was studied in seven type 1 diabetic patients treated first with continuous subcutaneous insulin infusion (CSII) and subsequently with continuous intraperitoneal insulin infusion (CIPII). Arterialised blood glucose and venous hormonal responses were analyzed. HbA1c was improved by CIPII. Although a regimen of a higher basal insulin infusion rate was applied during CIPII the basal peripheral venous insulin levels were lower. The i.v. bolus of insulin resulted in hypoglycaemia in both tests but was more pronounced during the CSII test expressed as a smaller area under the curve (AUC) for the first hour (13.0 +/- 2.3 vs. 13.7 +/- 1.2 mmol l(-1) h(-1), p=0.016, CSII vs. CIPII). The hypoglycaemia resulted in a significant and similar increase in the plasma levels of adrenaline, cortisol and growth hormone in both experiments. A significant increase in the glucagon level was only observed during CIPII. The incremental glucagon response was also significantly more pronounced in the CIPII test expressed as maximal responses (7.5 +/- 3.0 vs. 17.0 +/- 3.1 pg ml(-1), p =0.048, CSII vs. CIPII) as well as incremental AUC (5.1 +/- 12.0 vs. 44.4 +/- 13.2 pg ml(-1) h(-1), p =0.027, CSII vs. CIPII). It seems that CIPII in type 1 diabetic patients could improve the glucagon release to hypoglycaemia. This observation may contribute in explaining why CIPII is associated with a lower incidence of hypoglycaemia in spite of an improvement in metabolic control.

Acute effects of the alpha 2-adrenoreceptor antagonist idazoxan on hormonal responses and symptoms of hypoglycaemia in patients with type 1 diabetes mellitus.

The aim of the present study was to evaluate the effect of the alpha 2-adrenoceptor antagonist idazoxan on hormonal responses and hypoglycaemia symptoms in patients with insulin-dependent (Type 1) diabetes mellitus. Six male Type 1 diabetic patients were studied with and without intravenous infusion of idazoxan. Hypoglycaemia was induced by an intravenous infusion of insulin (100 mU.kg-1.h-1), together with a glucose clamp, to obtain an arterialised venous blood glucose level of 2.3 mmol/l. Idazoxan was given at a dose of 295 micrograms/kg. Venous blood samples were obtained for analyses of free insulin, growth hormone (GH), glucagon and catecholamines. Symptoms were scored on a visual-analogue rating scale. Areas under the curves with and without idazoxan were respectively 22.4 +/- 7.0 vs 33.0 +/- 9.6 micrograms.l-1.h (p = 0.17) for GH, 4.1 +/- 1.1 vs 2.4 +/- 0.9 nmol.l-1h (p < 0.05) for adrenaline, 5.6 +/- 0.9 vs 1.3 +/- 0.5 nmol.l-1.h (p < 0.05) for noradrenaline and 51 +/- 38 vs -40 +/- 11 ng.l-1.h (p < 0.05) for glucagon. Sweating and palpitations were more pronounced during idazoxan infusion than during the control test. It is concluded that idazoxan increases catecholamine and glucagon responses as well as some of the warning signals of hypoglycaemia in Type 1 diabetic patients, whereas the GH response seems less affected by idazoxan.

Accuracy of continuous nocturnal glucose screening after 48 and 72 hours in type 2 diabetes patients on combined oral and insulin therapy.

OBJECTIVE: To evaluate the accuracy of nocturnal continuous glucose monitoring by CGMS. RESEARCH DESIGN AND METHODS: A CGMS was inserted in 14 type 2 diabetic patients on combined oral and insulin therapy at altogether 15 occasions. During the second (48 hours) and third (72 hours) night of registration each subject was observed and plasma glucose was analysed seven times during the night by venous sampling and compared to CGMS. These venous values were not used for calibration of the sensor. Pairs of data were analysed using correlation coefficient, Bland-Altman graphs and Clarke Error Grid analysis. RESULTS: 32% of CGMS data did not meet the quality criteria for optimal accuracy and were excluded. A correlation coefficient of 0.80 (p < 0.0001) was seen after 48 hours and a lower coefficient of 0.33 (p = 0.0082) after 72 hours. Bland-Altman analyses demonstrated that the dispersion of the values around the mean of differences was wider after 72 hours as compared to after 48 hours. In the Clark Error Grid analysis 100% of data were within zones A and B after 48 hours, with 60% in zone A. After 72 hours only 44% were in zone A and 7% of data were in the clinically unacceptable zone D. CONCLUSION: The MiniMed Medtronic CGMS has acceptable nocturnal accuracy after 48 hours of registration, but the accuracy thereafter deteriorates with time, implicating that the CGMS thereafter may prove less useful for nocturnal monitoring.

Improved blood glucose variability, HbA1c insuman Infusat and less insulin requirement in IDDM patients using insulin lispro in CSII. The Swedish Multicenter Lispro Insulin Study.

The aim of the study was to compare lispro (LP) and Insuman(R) (I) insulin in continuous subcutaneous insulin infusion (CSII) therapy with respect to blood glucose control as expressed by the standard deviation of blood glucose (SD(BG) ) and HbA(1c) and to monitor the well-being (WBQ) and treatment satisfaction (DTSQ) parameters during such treatment. Forty-one IDDM patients who had used CSII for at least 6 months participated in an open-label, randomized, cross-over, multicenter study for 4 months (2 months LP and 2 months I or vice versa). Boluses with LP were given 5 min before each meal and with I 30 min before each meal. During LP administration compared with I, the SD(BG) of all blood glucose values (3.6 mmol/l vs. 3.9 mmol/l, p=0.012), as well as the SD(BG) of the postprandial, blood glucose values (3.6 mmol/l vs. 4.0 mmol/l, p=0.006), were significantly reduced. The HbA(1c) was significantly lower during LP administration (7.4% vs. 7.6%, p=0.047). The incidence of hypoglycemic events per 30 days (capillary blood glucose<3.0 mmol/l and/or symptoms) did not significantly differ between LP and I (9.7 vs. 8.0 per month, p=0.23). The total amount of daily insulin was slightly but significantly lower with LP, compared to I (38.0 IU vs. 40.3 IU, p=0.004). There was no treatment effects of LP compared to I concerning WBQ and DTSQ. It is concluded that in CSII therapy LP is superior to I with respect to the stability of blood glucose control, a lower HbA(1c), a less insulin requirement without increasing the frequency of hypoglycemia.

A randomised study evaluating the effects of cisapride on glucose variability and quality of life parameters in insulin-dependent diabetes mellitus patients.

This study evaluated the effect of cisapride on glycaemic control, well-being and treatment satisfaction in insulin-dependent diabetes mellitus (IDDM) patients with documented moderate to severe glycaemic instability. Thirty-seven patients with glycaemic instability were included in a randomized, double-blind, placebo-controlled, cross-over study. Patients were instructed to take cisapride 10 mg q.i.d. or placebo tablets q.i.d. (15 to 30 min before each of the three main meals and before bedtime) for two periods of four weeks. The first treatment period was followed by a wash-out period of four weeks, with placebo treatment. Patients measured blood glucose with a glucometer before breakfast, lunch, dinner, 90 min after dinner and before bedtime every two days. After each treatment period, glucose data were collected from the glucometer to calculate the standard deviation (SDBG) of self-monitored blood glucose (SMBG). Questionnaires designed to measure well-being and treatment satisfaction were also completed initially and after each of the two treatment periods. There were no treatment effects of cisapride compared to placebo with respect to SDBG, mean glucose, percentage of extremes, number of hypoglycaemic episodes, insulin requirement, insulin variability, well-being, or treatment satisfaction. Cisapride 10 mg q.i.d. given for four weeks did not affect diabetic control or well-being and treatment satisfaction in a group of IDDM patients with glycaemic instability, i.e. a standard deviation of blood-glucose > 3.9 mmol/l.