The effect of basal-bolus therapy varies with baseline 1,5-anhydroglucitol level in people with Type 2 diabetes: a post hoc analysis.

AIMS: To investigate the impact of baseline 1,5-anhydroglucitol on the treatment effect of basal-bolus therapy in people with Type 2 diabetes. METHODS: Post hoc analysis of onset 3, an 18-week, randomized, phase 3 trial evaluating the efficacy and safety of fast-acting insulin aspart in basal-bolus therapy (n = 116) vs. basal insulin-only therapy (n = 120) in people with Type 2 diabetes. The estimated treatment difference in change from baseline in HbA1c was investigated for different cut-off values of baseline 1,5-anhydroglucitol (2, 3, 4, 5 and 6 µg/ml). RESULTS: The estimated treatment difference in change from baseline in HbA1c between basal-bolus therapy and basal insulin-only therapy was statistically significantly greater in participants with baseline 1,5-anhydroglucitol ≤3 µg/ml (n = 34) vs. >3 µg/ml (n = 198) [estimated treatment difference (95% CI): -1.53% (-2.12; -0.94) vs. -0.82% (-1.07; -0.57); P-value for interaction = 0.03]. The estimated treatment difference became more pronounced when comparing participants with 1,5-anhydroglucitol ≤2 µg/ml (n = 15) vs. >2 µg/ml (n = 217) [estimated treatment difference (95% CI): -2.26% (-3.15; -1.36) vs. -0.85% (-1.08; -0.62); P-value for interaction = 0.003]. For cut-off values ≥4 µg/ml, estimated treatment differences were numerically greater below the cut-off compared with above, although the interaction terms were not statistically significant. CONCLUSION: This analysis indicates that people with Type 2 diabetes with low 1,5-anhydroglucitol have an added treatment benefit with basal-bolus therapy compared with people with higher 1,5-anhydroglucitol. Further research is needed to clarify any clinical utility of these findings. Clinical Trials Registry No: NCT01850615.

AMG 151 (ARRY-403), a novel glucokinase activator, decreases fasting and postprandial glycaemia in patients with type 2 diabetes.

Phase I studies have shown that AMG 151 activates glucokinase, a key enzyme in glucose homeostasis. The present randomized, placebo-controlled phase IIa study evaluated the dose-effect relationship of the glucokinase activator AMG 151 relative to placebo on fasting plasma glucose (FPG) in 236 patients (33-35 patients per arm) with type 2 diabetes treated with metformin. Patients received oral AMG 151 at 50, 100 or 200 mg twice daily, AMG 151 at 100, 200 or 400 mg once daily or matching placebo for 28 days. A significant linear dose-effect trend was observed with the twice-daily regimen (p = 0.004) for change in FPG to day 28. No trend was observed with the once-daily regimen. A higher incidence of hypoglycaemia and hypertriglyceridaemia was observed with AMG 151 administration. AMG 151 significantly reduced FPG when administered twice daily but not when administered once daily in patients with type 2 diabetes treated with metformin.

Effect of adding insulin degludec to treatment in patients with type 2 diabetes inadequately controlled with metformin and liraglutide: a double-blind randomized controlled trial (BEGIN: ADD TO GLP-1 Study).

AIM: To evaluate the efficacy and safety of adding insulin degludec (IDeg) to treatment in patients with type 2 diabetes receiving liraglutide and metformin and qualifying for treatment intensification because of inadequate glycaemic control. METHODS: In this 26-week, double-blind trial, patients who still had inadequate glycaemic control after a 15-week run-in period with initiation and dose escalation of liraglutide to 1.8 mg in combination with metformin (≥1500 mg) were randomized to addition of once-daily IDeg ('IDeg add-on to liraglutide' arm; n = 174) or placebo ('placebo add-on to liraglutide' arm; n = 172), with dosing of both IDeg and placebo based on titration guidelines. RESULTS: At 26 weeks, the mean change in glycated haemoglobin level was greater in the IDeg add-on to liraglutide arm (-1.04%) than in the placebo add-on to liraglutide arm (-0.16%; p < 0.0001). Similarly, the mean fasting plasma glucose reduction was greater, and self-measured plasma glucose values were lower at all eight time points, with IDeg add-on versus placebo add-on (both p < 0.0001). At 26 weeks, the IDeg dose was 51 U (0.54 U/kg). During the run-in period with liraglutide, body weight decreased by ∼3 kg in both groups. After 26 weeks, the mean change was +2.0 kg (IDeg add-on to liraglutide) and -1.3 kg (placebo add-on to liraglutide). Confirmed hypoglycaemia rates were low in both groups, although higher with IDeg than with placebo (0.57 vs. 0.12 episodes/patient-years of exposure; p = 0.0002). Nocturnal confirmed hypoglycaemia was infrequent in both groups, with no episodes of severe hypoglycaemia, and no marked differences in adverse events with either treatment approach. CONCLUSION: The addition of liraglutide and IDeg to patients sub-optimally treated with metformin and liraglutide and requiring treatment intensification was found to be effective and well-tolerated.

Pulmonary function over 2 years in diabetic patients treated with prandial inhaled Technosphere Insulin or usual antidiabetes treatment: a randomized trial.

AIMS: Development of inhaled insulin has increased the need to understand its pulmonary safety. This study evaluated pulmonary function changes in diabetes patients receiving inhaled Technosphere Insulin (TI) or usual antidiabetes treatment (usual care). METHODS: This randomized, open-label study was conducted at 220 sites (25 July 2005 to 29 August 2008). Pulmonary function tests [forced expiratory volume in 1 s (FEV(1)), forced vital capacity (FVC), total lung capacity (TLC) and lung diffusion capacity for carbon monoxide (DL(CO))] were prospectively followed over 2 years in patients with type 1 or type 2 diabetes receiving TI (n = 730) or usual care (n = 824), along with a cohort without diabetes not receiving any specific therapy (n = 145). RESULTS: Baseline demographics and pulmonary function were similar between diabetes treatment groups. Lung function declined from baseline in all groups. TI was non-inferior to usual care for mean change in FEV(1) from baseline to month 24 [mean (s.e.m.) 0.037 (0.0119) l; 95% CI 0.014 to 0.060] using mixed-model repeated-measure with a pre-specified non-inferiority margin of 50 ml/year. After a greater initial decline at month 3 with TI, rate of change (slope) in FEV(1), FVC and DL(CO) (months 3-24) was not statistically different between treatment groups. TI was well tolerated; no serious safety concerns emerged. The most common respiratory event associated with TI was mild, transient cough, occurring within minutes of inhalation. CONCLUSIONS: Observed changes in lung function with TI were small, occurred early after therapy initiation, remained non-progressive over 2 years and were unlikely to be clinically meaningful.

Glycaemic control with liraglutide: the phase 3 trial programme.

AIMS: To review the efficacy and safety of liraglutide from the phase 3 trials, focusing primarily on glycaemic control. KEY FINDINGS: Liraglutide was shown to reduce glycated haemoglobin (HbA(1c) ) levels by up to 1.5% from baseline, significantly more than the comparators sitagliptin (-0.9%), glimepiride (-0.5%), rosiglitazone (-0.4%), insulin glargine (-1.1%) and exenatide (-0.8%). Both fasting plasma glucose (FPG) and postprandial plasma glucose (PPG) levels were shown to be significantly reduced from baseline [up to -2.4 mmol/l (-43.2 mg/dl) and -2.7 mmol/l (-48.6 mg/dl) for FPG and PPG in the liraglutide 1.8 mg group, respectively]. Changes in HbA(1c) , FPG and PPG levels were sustained for the duration of the studies (up to 52 weeks). The glycaemic control offered by liraglutide was not associated with an increased rate of minor hypoglycaemic events compared with comparator treatments, with rates significantly lower than those of glimepiride and exenatide. Major hypoglycaemic events were rare and only occurred in combination with a sulfonylurea. Nausea was the most frequent adverse event, but subsided within the first few weeks. CONCLUSIONS: Liraglutide has been shown to offer effective glycaemic control for patients with type 2 diabetes and is appropriate for use across the conventional continuum of care. Despite the sustained reductions in HbA(1c) , FPG and PPG levels achieved with liraglutide, rates of minor hypoglycaemia were generally low, although the risk increased when combined with a sulfonylurea. Liraglutide is therefore a promising new option for the treatment of type 2 diabetes.

Arterial constrictor response in a diving mammal.

Angiograms were obtained in the harbor seal, Phoca vitulina, in air and during diving. During diving there is arterial constriction of the vascular beds of muscle, skin, kidney, liver, spleen, and presumably of all vascular beds except those perfusing the brain and heart. There is sudden constriction and narrowing of muscular arteries close to their origin from the aorta. Constriction of small arterial branches is so intense that blood flow is essentially lost in all involved organs.

Twice-daily dosing of a repaglinide/metformin fixed-dose combination tablet provides glycaemic control comparable to rosiglitazone/metformin tablet.

AIM: To assess the use of a new repaglinide/metformin fixed-dose combination (FDC) tablet for the treatment of type 2 diabetes. METHODS: In this 26-week, multicentre, open-label, parallel-group trial, subjects poorly controlled with mono- or dual-oral antidiabetic therapy were randomized 1 : 1 : 1 to receive a repaglinide/metformin FDC tablet either two times daily (BID) or three times daily (TID) or a rosiglitazone/metformin FDC tablet BID. The primary objective comprised two hypotheses tested in a hierarchical order: (i) that treatment with the repaglinide/metformin FDC BID is non-inferior to that of a rosiglitazone/metformin FDC tablet BID as measured by changes in haemoglobin A1c (HbA1c) (results presented here) and (ii) if true, that treatment with the repaglinide/metformin FDC BID was non-inferior to that of the repaglinide/metformin FDC TID as measured by changes in HbA1c (results presented in a companion paper). Additional efficacy and safety end-points were also assessed. RESULTS: Of the 561 subjects randomized, 383 completed the study. Reductions in HbA1c values became apparent at earlier times for repaglinide/metformin FDC BID treatment than rosiglitazone/metformin FDC BID, and final changes in HbA1c were not significantly different between treatment arms (p = 0.8186); thus, the predefined statistical criterion for non-inferiority was met. Overall adverse event profiles were comparable between treatment groups, and no major hypoglycaemic episodes were reported during the study. CONCLUSIONS: The repaglinide/metformin FDC BID regimen showed efficacy that was non-inferior to that of the rosiglitazone/metformin FDC BID regimen currently in clinical use and a more rapid reduction of HbA1c values. Thus, repaglinide/metformin FDC BID is a clinically feasible alternative to rosiglitazone/metformin FDC BID.

Twice-daily and three-times-daily dosing of a repaglinide/metformin fixed-dose combination tablet provide similar glycaemic control.

AIM: To assess the efficacy and safety of a new repaglinide/metformin fixed-dose combination (FDC) tablet administered either twice a day (BID) or three times a day (TID) for the management of type 2 diabetes. METHODS: This was a 26-week, multicentre, open-label parallel trial in which subjects poorly controlled with mono- or dual-oral antidiabetic therapy were randomized 1 : 1 : 1 to instead receive repaglinide/metformin FDC either BID or TID or a rosiglitazone/metformin FDC BID. Two primary hypotheses were tested in a hierarchical manner: (i) treatment with the repaglinide/metformin FDC BID is non-inferior to that of the rosiglitazone/metformin FDC BID as measured by changes in haemoglobin A1c (HbA1c) (results presented in companion paper) and (ii) repaglinide/metformin BID is non-inferior to repaglinide/metformin TID (as measured by changes in HbA1c). Additional efficacy and safety end-points were also assessed. RESULTS: A total of 561 subjects were randomized; 383 completed the study. Repaglinide/metformin FDC BID was non-inferior to repaglinide/metformin FDC TID with respect to HbA1c. Additionally, changes in mean fasting plasma glucose values from baseline to end of study were not significantly different between the BID and the TID dose groups. There were no major hypoglycaemic episodes reported in either group during the trial, and overall adverse event profiles were similar. CONCLUSION: The efficacy of twice-daily dosing of a repaglinide/metformin FDC tablet was non-inferior to that of three-times-daily dosing.

Patient-directed titration for achieving glycaemic goals using a once-daily basal insulin analogue: an assessment of two different fasting plasma glucose targets - the TITRATE study.

AIMS: To compare efficacy and safety of two fasting plasma glucose (FPG) titration targets [4.4-6.1 mmol/l (80-110 mg/dl) and 3.9-5.0 mmol/l (70-90 mg/dl)] using a patient-directed, treat-to-target algorithm for once-daily basal insulin in insulin-naïve subjects with type 2 diabetes suboptimally treated with oral antidiabetes drugs (OADs). METHODS: In this 20-week, randomized, controlled, open-label, multicentre, treat-to-target study, 244 insulin-naïve subjects with type 2 diabetes, HbA(1c)>or=7.0 and

Addition of biphasic insulin aspart 30 to optimized metformin and pioglitazone treatment of type 2 diabetes mellitus: The ACTION Study (Achieving Control Through Insulin plus Oral ageNts).

AIM: Efficacy and safety of biphasic insulin aspart (BIAsp 30, 30% short-acting and 70% intermediate-acting insulin aspart) added to an optimized treatment of metformin and pioglitazone (met/pio) were compared with treatment with optimized met/pio in type 2 diabetes patients. METHODS: This randomized, 34-week, parallel-group study enrolled insulin-naive, type 2 diabetes patients (HbA(1c) 7.5-12.0%) previously using two oral antidiabetic (OAD) agents. During an 8-week run-in period, treatment was changed to met/pio and doses were adjusted up to 2500 mg/day and 30 or 45 mg/day respectively. Subjects either continued met/pio alone or added BIAsp 30 initiated at 6 units twice daily and titrated to target plasma glucose (PG) (4.4-6.1 mmol/l). RESULTS: At end-of-study, subjects treated with BIAsp 30+met/pio (n = 93) had a mean (+/-s.d.) HbA(1c) reduction significantly greater than treatment with met/pio (n = 88) (1.5% +/- 1.1 vs. 0.2% +/- 0.9, p < 0.0001 between groups). Subjects treated with BIAsp 30+met/pio were more likely to reach The American Association of Clinical Endocrinologists and European Association for the Study of Diabetes/American Diabetes Association HbA(1c) targets of < or =6.5 and <7.0%, respectively, than with met/pio only (HbA(1c)< or =6.5%: 59 vs. 12%; HbA(1c) <7.0%: 76 vs. 24%). At end-of-study, self-monitored glucose profile values at all eight daily time points were significantly less for the BIAsp 30+met/pio group compared with the met/pio group, and minor hypoglycaemia (defined as PG < 3.1 mmol/l) was more frequent (8.3 vs. 0.1 events/year, p < 0.001). Both groups gained weight during treatment (BIAsp 30+met/pio, 4.6 +/- 4.3 kg; met/pio, 0.8 +/- 3.2 kg; p < 0.001). CONCLUSION: Addition of insulin in type 2 patients treated with met/pio is an effective way to achieve glycaemic targets. Treatment with BIAsp 30+met/pio achieved significantly greater reduction in HbA(1c), as compared with met/pio alone. In patients with type 2 diabetes poorly controlled by 2 OADs, more achieved glycaemic targets using BIAsp 30+met/pio than using met/pio alone.

Does serum 1,5-anhydroglucitol establish a relationship between improvements in HbA1c and postprandial glucose excursions? Supportive evidence utilizing the differential effects between biphasic insulin aspart 30 and insulin glargine.

AIM: To investigate the relationship between changes in glycated haemoglobin (HbA(1c)) and postprandial glucose excursions on 1,5-anhydroglucitol (1,5-AG) in patients with Type 2 diabetes, utilizing the differential effects between biphasic insulin aspart 30 (BIAsp 30) or insulin glargine (IGlar) on postprandial glucose (PPG) levels. METHODS: 1,5-AG was measured using the GlycoMark assay at baseline and after 12 and 28 weeks in the INITiation of Insulin to reach HbA(1c) Target (INITIATE) study of 233 patients randomized to either BIAsp 30 or IGlar. RESULTS: Baseline 1,5-AG was low and not significantly different (4.9 +/- 3.5 and 4.3 +/- 2.6 microg/ml in the BIAsp 30 and IGlar groups, respectively). After 28 weeks, the levels of 1,5-AG were higher in the BIAsp 30 than in the IGlar group (13.4 vs. 11.1 microg/ml, P = 0.008) and change from baseline was 25% greater with BIAsp 30 than IGlar (8.4 vs. 6.7 microg/ml, P = 0.011). 1,5-AG levels increased as a function of decreasing HbA(1c) or the average change in postprandial plasma glucose (PPG(ave)) with significant relationships for 1,5-AG/ HbA(1c) vs. HbA(1c) or 1,5-AG/PPG(ave )vs. PPG(ave) (both P < 0.0001), respectively. CONCLUSIONS: As reported in previous publications, 1,5-AG reflects ambient glycaemic control and increases with reductions in HbA(1c) and postprandial glucose. The greater reductions in postprandial excursion achieved with BiAsp 30 compared with glargine were associated with greater increases in 1,5-AG. Even moderate elevations in HbA(1c) substantially lower 1,5-AG, suggesting that it can be most discriminating in identifying patients with excessive postprandial glucose excursions at HbA(1c) levels that approach the upper end of the normal range.

Oral combination therapy: repaglinide plus metformin for treatment of type 2 diabetes.

Type 2 diabetes is characterized by decreases in insulin secretion and insulin sensitivity. Several classes of oral antidiabetic medications are currently approved for the treatment of type 2 diabetes. A stepwise treatment approach from monotherapy to combination therapy is traditionally used; however, the frequency of treatment failure with monotherapy has resulted in a move towards earlier treatment with combination therapies that target the two principal defects in glycaemic control. One such combination regimen is repaglinide (a prandial glucose regulator that increases insulin release) plus metformin (an insulin sensitizer that inhibits hepatic glucose output, increases peripheral glucose uptake and utilization and minimizes weight gain). Findings from several clinical trials have shown that combination therapy with repaglinide plus metformin is well tolerated and results in greater reductions of haemoglobin A(1c) and fasting plasma glucose values compared with either monotherapy. Repaglinide may also provide a more suitable alternative to combination therapy with sulphonylureas and metformin because of its reduced propensity for hypoglycaemia. The combination regimen of repaglinide plus metformin should therefore be considered as a valuable option in the management of patients with type 2 diabetes when monotherapy is no longer adequate.

Effect of insulin-glucose infusions on plasma glucagon levels in fasting diabetics and nondiabetics.

The effect of the intravenous infusion of insulin plus glucose on plasma glucagon levels was studied in hyperglycemic fasting adult-type and juvenile-type diabetics and compared with fasting nondiabetics. Adult-type diabetics were given insulin for 2 h at a rate of 0.03 U/kg-min, raising their mean insulin to between 25 and 36 muU/ml; glucagon declined from a base-line value of 71+/-2 (SEM) to 56+/-1 pg/ml at 120 min (P less than 0.001). In juvenile-type diabetics given the same insulin-glucose infusion, glucagon declined from a base-line level of 74+/-8 to 55+/-5 pg/ml at 120 min (P less than 0.05). The absolute glucagon values in the diabetic groups did not differ significantly at any point from the mean glucagon levels in nondiabetics given insulin at the same rate plus enough glucose to maintain normoglycemia. When glucagon was expressed as percent of baseline, however, the normoglycemic nondiabetics exhibited significantly lower values than adult-type diabetics at 90 and 120 min and juvenile-type diabetics at 60 min. In nondiabetics given insulin plus glucose at a rate that caused hyperglycemia averaging between 134 and 160 mg/dl, glucagon fell to 41+/-7 pg/ml at 120 min, significantly below the adult diabetics at 90 and 120 min (P less than 0.01 and less than 0.05) and the juvenile group at 60 min (P less than 0.01). The mean minimal level of 39+/-2 pg/ml was significantly below the adult (P less than 0.001) and juvenile groups (P less than 0.05). When insulin was infused in the diabetic groups at a rate of 0.4 U/kg-min together with glucose, raising mean plasma insulin to between 300 and 600 muU/ml, differences from the hyperglycemic nondiabetics were no longer statistically significant. It is concluded that, contrary to the previously reported lack of insulin effect in diabetics during carbohydrate meals, intravenous administration for 2 h of physiologic amounts of insulin plus glucose is accompanied in unfed diabetics by a substantial decline in plasma glucagon. These levels are significantly above hyperglycemic nondiabetics at certain points but differ from normoglycemic nondiabetics only when expressed as percent of the baseline. At a supraphysiologic rate of insulin infusion in diabetics, these differences disappear.

Monocyte-T lymphocyte interaction for regulation of insulin receptors of the activated T lymphocyte.

During activation the lymphocyte attains functional insulin receptors with precise regulation, a consequence of insulin concentration manipulations. These studies test the hypothesis that insulin receptor (+) monocytes monitor insulin concentrations, so instructing the T lymphocytes. Monocyte-enriched populations were incubated with insulin (0-10(-6) M) followed by co-culture with T lymphocytes and an activating stimulus. A dose-related fall in T lymphocyte insulin receptor binding was observed that was specific for the monocyte as the signalling cell and for insulin as the signal received. Monocytes from normal volunteers during a euglycemic, hyperinsulinemic clamp were cultured with T lymphocytes and an activating stimulus. A decline in specific insulin receptor binding on T lymphocytes was observed, which Scatchard analysis demonstrated to be a consequence of reduction in receptor numbers. These studies demonstrate that the receptor (+) monocyte perceives the concentration of insulin and passes this information to T lymphocytes regulating the number of activation-induced insulin receptors. The interplay between the monocyte and T lymphocyte parallels the interaction of these cell types for recognition of antigen.

Crucial role of aldose reductase activity and plasma glucose level in sorbitol accumulation in erythrocytes from diabetic patients.

Increased sorbitol levels have been demonstrated in tissues of diabetic patients. Although tissue sorbitol levels correlate with plasma glucose levels, a large variability in sorbitol levels has been observed among diabetic patients with similar plasma glucose levels. This variability in tissue sorbitol levels may be due to differences in the activity of aldose reductase, the enzyme that converts glucose to sorbitol. In this study, we isolated aldose reductase from erythrocytes of 31 diabetic patients and 6 nondiabetic control subjects, measured its activity, and compared it to simultaneously measured erythrocyte sorbitol levels. The activity of erythrocyte aldose reductase was increased in diabetic patients compared with control subjects (28.1 +/- 1.4 vs. 22.4 +/- 1.7 nmol.min-1.g-1 Hb, P less than 0.05), but there was an approximately threefold variation in aldose reductase activity among diabetic patients. Erythrocyte aldose reductase activity and fasting plasma glucose levels significantly correlated with the erythrocyte sorbitol level in all individuals (r = 0.48, P less than 0.005 and r = 0.63, P less than 0.005, respectively). The sorbitol level was higher in patients with high aldose reductase activity than in those who had low enzyme activity for any given level of glycemia. The sorbitol production rate calculated from Km and Vmax values showed a better correlation with the erythrocyte sorbitol level (r = 0.80, P less than 0.005), and there was also a good correlation between the erythrocyte sorbitol level and the product of aldose reductase activity by plasma glucose level (r = 0.70, P less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in glucagon levels after four to five weeks of glucoregulation by portable insulin infusion pumps.

Near-normal glucoregulation was maintained in five patients with juvenile-onset diabetes mellitus for 4--5 wk with a preprogrammed, continuous, subcutaneous insulin infusion using a portable battery-powered infusion pump. This form of therapy significantly lowered immunoreactive glucagon (IRG) levels below those observed while on conventional insulin treatment at several times during the 24-h profile. The maximum IRG levels were also reduced in all five subjects. Thus, a flexible system of insulin delivery, as is provided by certain open-loop pump systems, can overcome inappropriate glucagon secretion that occurs with conventional insulin therapy.

Effect of intensive diabetes treatment on low-density lipoprotein apolipoprotein B kinetics in type I diabetes.

The metabolism of low-density lipoprotein (LDL) was studied in six insulin-dependent (type I) diabetic patients during a 7-wk period of conventional and intensive therapy with insulin. Plasma glucose and HbA1c were normalized, demonstrating the effectiveness of our intensive treatment program. Plasma lipoprotein profiles and LDL apolipoprotein B kinetic parameters were estimated during conventional and then during intensive therapy for each patient. Intensive therapy resulted in a significant reduction of plasma and LDL cholesterol and an increase in high-density lipoprotein (HDL) cholesterol. The lower LDL levels resulted from a decreased production of lipoprotein rather than an increased fractional catabolic rate. These results are consistent with our previous observations of very-low-density lipoprotein (VLDL) metabolism during intensive therapy. VLDL production is significantly reduced; thus, a decreased production of LDL supports the contention that intensive therapy with insulin in normolipemic type I diabetic patients reduces the production of lipoproteins containing apolipoprotein B rather than increasing the clearance, and therapy also increases HDL cholesterol. Both of these effects may be beneficial in reducing the risk for coronary heart disease in type I diabetes.

Effect of insulin on the exaggerated glucagon response to arginine stimulation in diabetes mellitus.

The effect of insulin on the glucagon response to intravenous arginine was studied in eight juvenile-type and six adult-onset diabetics. In the juvenile-type diabetics, concomitant administration of insulin significantly blunted the glucagon response from a mean maximal rise of 310 +/- 54 pg./ml. to only 184 +/- 39 pg./ml. (p less than 0.01), about the same as in nondiabetics. In the adult-onset patients, however, insulin had no effect, the mean maximal rise being 250 +/- 50 pg./ml. without insulin and 307 +/- 71 pg./ml. with insulin (N.S.). This study demonstrates that in juvenile-type diabetics concomitant administration of supraphysiologic quantities of insulin can reduce the exaggerated glucagon response to intravenous arginine to normal, whereas in the adult-type group, it has no apparent effect.

The effect of improved diabetic control on plasma lipid and lipoprotein levels: a comparison of conventional therapy and continuous subcutaneous insulin infusion.

We studied short-term changes in plasma lipid levels in type I diabetics treated with either a conventional insulin regimen or continuous subcutaneous insulin infusion. Mean plasma glucose dropped from 260 +/- 18 to 134 +/- 8 mg/dl when conventional treatment was used and from 194 +/- 18 to 108 +/- 8 mg/dl with CSII. Both forms of therapy were associated with a significant fall in plasma triglyceride levels. However, only CSII treatment produced significant changes in total plasma cholesterol and LDL cholesterol levels. Total cholesterol fell from 195 +/- 17 mg/dl to 161 +/- 11 mg/dl and LDL cholesterol fell from 129 +/- 13 mg/dl to 102 +/- 9 mg/dl. We conclude that improved diabetic control by any method is effective in lowering plasma triglyceride levels, but it requires almost perfect metabolic control to affect plasma cholesterol and LDL cholesterol levels. The changes in plasma lipid and lipoprotein achieved with CSII may favorably alter the prediction for the development of premature atherosclerosis in our patients.

Changes in nerve conduction velocity after six weeks of glucoregulation with portable insulin infusion pumps.

Near normal glucoregulation was maintained in 10 patients with insulin-dependent (type I) diabetes mellitus for 6 wk with preprogrammed continuous subcutaneous insulin infusion using a portable battery-powered infusion pump (CSII). This form of therapy resulted in a statistically significant increase in motor nerve conduction velocity in the median and peroneal nerves compared with baseline values. There was no significant change in the motor nerve conduction velocity in the ulnar nerve or in the sensory nerve conduction studies. No changes occurred in five additional patients studied in similar fashion while on a conventional insulin regimen. These results suggest that the prevention of sustained hyperglycemia with CSII could theoretically result in the prevention of diabetic neuropathy. However, only long-term studies of CSII will provide the information necessary to determine the clinical relevance of the findings.