Children and adolescents with type 1 and type 2 diabetes mellitus in the Pediatric Diabetes Consortium Registries: comparing clinical characteristics and glycaemic control.

AIM: To compare the characteristics of children and adolescents with type 1 vs. type 2 diabetes in the Pediatric Diabetes Consortium (PDC) registries. METHODS: Participants were 10 to < 21 years of age at diagnosis; there were 484 with type 1 diabetes and 1236 with type 2 diabetes. RESULTS: Children and adolescents with type 2 diabetes were more likely to be female, overweight/obese, and from low-income, minority ethnic families. Children and adolescents with type 1 diabetes were more likely to present with diabetic ketoacidosis and have higher mean HbA1c levels at diagnosis. More than 70% in both cohorts achieved target HbA1c levels < 58 mmol/mol (< 7.5%) within 6 months, but fewer participants with type 1 than type 2 diabetes were able to maintain target HbA1c levels after 6 months consistently throughout 3 years post diagnosis. Of the 401 participants with type 2 diabetes with ≥ 24 months diabetes duration on enrolment in the registry, 47% required no insulin treatment. Median C-peptide levels were 1.43 mmol/l in the subset of participants with type 2 diabetes in whom it was measured, but only 0.06 mmol/l in the subset with type 1 diabetes. CONCLUSIONS: Although families of children and adolescents with type 2 diabetes face greater socio-economic obstacles and risk factors for poor diabetes outcomes, the greater retention of residual endogenous insulin secretion likely contributes to the increased ability of children and adolescents with type 2 diabetes to maintain target HbA1c during the first 3 years of diabetes diagnosis.

Time spent outside of target glucose range for young children with type 1 diabetes: a continuous glucose monitor study.

AIM: To assess the associations between demographic and clinical characteristics and sensor glucose metrics in young children with type 1 diabetes, using masked, continuous glucose monitoring data from children aged 2 to < 8 years. RESEARCH DESIGN AND METHODS: The analysis included 143 children across 14 sites in the USA, enrolled in a separate clinical trial. Eligibility criteria were: age 2 to <8 years; type 1 diabetes duration ≥3 months; no continuous glucose monitoring use for past 30 days; and HbA1c concentration 53 to <86 mmol/mol (7.0 to <10.0%). All participants wore masked continuous glucose monitors up to 14 days. RESULTS: On average, participants spent the majority (13 h) of the day in hyperglycaemia (>10.0 mmol/l) and a median of ~1 h/day in hypoglycaemia (<3.9 mmol/l). Participants with minority race/ethnicity and higher parent education levels spent more time in target range, 3.9-10.0 mmol/l, and less time in hyperglycaemia. More time in hypoglycaemia was associated with minority race/ethnicity and younger age at diagnosis. Continuous glucose monitoring metrics were similar in pump and injection users. CONCLUSIONS: Given that both hypo- and hyperglycaemia negatively impact neurocognitive development, strategies to increase time in target glucose range for young children are needed.

Pharmacokinetic and pharmacodynamic profile of the sodium-glucose co-transporter-2 inhibitor empagliflozin in young people with Type 2 diabetes: a randomized trial.

AIMS: To assess the pharmacokinetic and pharmacodynamic profile of a single dose of empagliflozin in young people with Type 2 diabetes to identify the appropriate doses for further paediatric development. METHODS: We conducted a single-dose, open-label, randomized, parallel-group study with empagliflozin 5 mg, 10 mg and 25 mg in young people with Type 2 diabetes aged 10-17 years. RESULTS: Of 39 participants screened, 27 were randomized and completed the study; their mean (± sd) age was 14.1±2.0 years and body weight was 96.7±23.5 kg. Compared with similar studies in adults with Type 2 diabetes, the maximum observed plasma concentrations were slightly lower with the 10-mg and 25-mg doses, and the area under the plasma concentration-time curve was slightly lower with the 10-mg but slightly higher with the 25-mg dose. The adjusted mean increases in urinary glucose excretion were 53 g/24 h (95% CI 32,74), 73 g/24 h (95% CI 52,94) and 87 g/24 h (95% CI 68,107), and the adjusted mean decreases in fasting plasma glucose were 0.9 mmol/l (95% CI -1.6,-0.1), 0.9 mmol/l (95% CI -1.7,-0.2) and 1.1 mmol/l (95% CI -1.8,-0.5) for the 5- 10- and 25-mg doses, respectively. There were no serious adverse events and one investigator-reported drug-related event (dehydration). CONCLUSIONS: After a single oral dose of empagliflozin, adults and young people with Type 2 diabetes had similar exposure-response relationships after adjusting for significant covariates. These data support testing 10-mg and/or 25-mg doses of empagliflozin in an upcoming paediatric phase III Type 2 diabetes trial. (ClinicalTrials.gov registration no.: NCT02121483).

Persistently high glucose levels in young children with type 1 diabetes.

OBJECTIVES: The aim of the study was to characterize glucose levels and variability in young children with type 1 diabetes (T1D). METHODS: A total of 144 children of 4-10 yr old diagnosed with T1D prior to age 8 were recruited at five DirecNet centers. Participants used a continuous glucose monitor (CGM) every 3 months during an 18-month study. Among the 144 participants, 135 (mean age 7.0 yr, 47% female) had a minimum of 48 h of CGM data at more than five of seven visits and were included in analyses. CGM metrics for different times of day were analyzed. RESULTS: Mean hemoglobin A1c (HbA1c) at the beginning and end of the study was 7.9% (63 mmol/mol). Fifty percent of participants had glucose levels >180 mg/dL (10.0 mmol/L) for >12 h/d and >250 mg/dL (13.9 mmol/L) for >6 h/d. Median time <70 mg/dL (3.9 mmol/L) was 66 min/d and <60 mg/dL (3.3 mmol/L) was 39 min/d. Mean amplitude of glycemic excursions (MAGE) was lowest overnight (00:00-06:00 hours). The percent of CGM values 71-180 mg/dL (3.9-10.0 mmol/L) and the overall mean glucose correlated with HbA1c at all visits. There were no differences in CGM mean glucose or coefficient of variation between the age groups of 4 and <6, 6 and <8, and 8 and <10. CONCLUSIONS: Suboptimal glycemic control is common in young children with T1D as reflected by glucose levels in the hyperglycemic range for much of the day. New approaches to reduce postprandial glycemic excursions and increase time in the normal range for glucose in young children with T1D are critically needed. Glycemic targets in this age range should be revisited.

Glycaemic control of Type 1 diabetes in clinical practice early in the 21st century: an international comparison.

AIMS: Improving glycaemic control in people with Type 1 diabetes is known to reduce complications. Our aim was to compare glycaemic control among people with Type 1 diabetes using data gathered in regional or national registries. METHODS: Data were obtained for children and/or adults with Type 1 diabetes from the following countries (or regions): Western Australia, Austria, Denmark, England, Champagne-Ardenne (France), Germany, Epirus, Thessaly and Thessaloniki (Greece), Galway (Ireland), several Italian regions, Latvia, Rotterdam (The Netherlands), Otago (New Zealand), Norway, Northern Ireland, Scotland, Sweden, Volyn (Ukraine), USA and Wales) from population or clinic-based registries. The sample size with available data varied from 355 to 173 880. Proportions with HbA1c < 58 mmol/mol (< 7.5%) and ≥ 75 mmol/mol (≥ 9.0%) were compared by age and sex. RESULTS: Data were available for 324 501 people. The proportions with HbA1c 58 mmol/mol (< 7.5%) varied from 15.7% to 46.4% among 44 058 people aged < 15 years, from 8.9% to 49.5% among 50 766 people aged 15-24 years and from 20.5% to 53.6% among 229 677 people aged ≥ 25 years. Sex differences in glycaemic control were small. Proportions of people using insulin pumps varied between the 12 sources with data available. CONCLUSION: These results suggest that there are substantial variations in glycaemic control among people with Type 1 diabetes between the data sources and that there is room for improvement in all populations, especially in young adults.

Incentivizing behaviour change to improve diabetes care.

Behavioural economics refers to the study of psychological and cognitive factors that relate to decision-making processes. This field is being applied increasingly to health care settings, in which patients receive tangible reinforcers or incentives for meeting objective behavioural criteria consistent with healthy lifestyles. This article reviews the background and efficacy of reinforcement interventions in general, and then as applied to behaviours related to diabetes prevention and management. Specifically, reinforcement interventions have been applied with some notable success towards promoting greater attendance at medical appointments, enhancing weight loss efforts, augmenting exercising regimes, improving medication adherence and increasing blood glucose monitoring. Suggestions for promising areas of future research are provided, keeping in mind the controversial nature of these interventions.

Satisfaction with continuous glucose monitoring in adults and youths with Type 1 diabetes.

AIMS: To describe satisfaction with continuous glucose monitoring in Type 1 diabetes; to correlate continuous glucose monitoring satisfaction scores with usage; and to identify common themes in perceived benefits and barriers of monitoring reported by adults, youths and the parents of youths in the Juvenile Diabetes Research Foundation continuous glucose monitoring trials. METHODS: The Continuous Glucose Monitoring Satisfaction Scale questionnaire was completed after 6 months of monitoring. Participants also answered open-ended queries of positive and negative attributes of continuous glucose monitoring. RESULTS: More frequent monitoring was associated with higher satisfaction for adults (n = 224), youths (n = 208) and parents of youths (n = 192) (all P < 0.001) in both the 'benefits' and 'hassles' sub-scales of the Continuous Glucose Monitoring Satisfaction Scale, but the greatest differences between the two groups involved scores on hassle items. Common barriers to monitoring use included insertion pain, system alarms and body issues; while common benefits included glucose trend data, opportunities to self-correct out-of-range glucose levels and to detect hypoglycaemia. CONCLUSIONS: As frequent use of continuous glucose monitoring is associated with improved glycaemic control without increased hypoglycaemia it is important to overcome barriers, reinforce benefits and set realistic expectations for this technology in order to promote its more consistent and frequent use in individuals with Type 1 diabetes.

Effect of insulin-like growth factor-1 on the responses to and recognition of hypoglycemia in humans. A comparison with insulin.

Recombinant human insulin-like growth factor-1 (rhIGF-1) lowers blood glucose in humans but its effect on counterregulatory responses has not been established. We therefore compared infusions of rhIGF-1 (0.7 micrograms/kg per min) and insulin (0.8 mU/kg.min) for 120 min in 10 healthy volunteers (glucose allowed to fall freely). With both, glucose fell rapidly because of stimulation of glucose uptake and suppression of hepatic glucose production. Despite similar plasma glucose nadirs (2.6 +/- 0.1 vs. 2.7 +/- 0.1 mM), the glucagon response was absent (P < 0.005), growth hormone release was attenuated (P < 0.03), and norepinephrine levels were increased (P < 0.05) by rhIGF-1 compared with insulin. Absent glucagon responses were associated with a blunting of the rebound increase in glucose production (P < 0.05 vs. insulin). After stopping the infusions, glucose recovery was delayed with rhIGF-1 (P < 0.001 vs. insulin). To further evaluate the effects of rhIGF-1 during a standard hypoglycemic stimulus, eight additional healthy subjects received rhIGF-1 or insulin while glucose was clamped at 2.8 mM. Again the rise in glucagon during insulin-induced hypoglycemia was totally abolished by rhIGF-1. Growth hormone responses were delayed, whereas increases in norepinephrine, heart rate, and symptomatic awareness of hypoglycemia were greater with rhIGF-1 compared with insulin (P < 0.05). It was concluded that rhIGF-1 suppression of glucagon release during hypoglycemia impairs glucose recovery. Paradoxically, awareness of hypoglycemia is enhanced with rhIGF-1 in part due to stimulation of the sympathetic activity.

Local ventromedial hypothalamus glucose perfusion blocks counterregulation during systemic hypoglycemia in awake rats.

The ventromedial hypothalamic nucleus (VMH) is necessary for the integrated hormonal response to hypoglycemia. To determine the role of the VMH as a glucose sensor, we performed experiments designed to specifically prevent glucopenia in the VMH, while producing hypoglycemia elsewhere. We used awake chronically catheterized rats, in which local VMH glucose perfusion (100 mM or 15 mM of D-glucose) was combined with a sequential euglycemic-hypoglycemic clamp. In two control groups the VMH was perfused either with (a) an iso-osmotic solution lacking glucose, or with (b) nonmetabolizable L-glucose (100 mM). During systemic hypoglycemia glucagon and catecholamine concentrations promptly increased in the control animals perfused with either 100 mM L-glucose or the iso-osmotic solution lacking glucose. In contrast, glucagon, epinephrine and norepinephrine release was inhibited in the animals in which the VMH was perfused with D-glucose; hormonal secretion was partially suppressed by the VMH perfusion with 15 mM D-glucose and suppressed by approximately 85% when the VMH was perfused with 100 mM D-glucose, as compared with the control groups. We conclude that the VMH must sense hypoglycemia for full activation of catecholamine and glucagon secretion and that it is a key glucose sensor for hypoglycemic counterregulation.

Influence of basal insulin and glucagon secretion on potassium and sodium metabolism. Studies with somatostatin in normal dogs and in normal and diabetic human beings.

To examine the role of basal insulin and glucagon secretion in potassium and sodium homeostasis, somatostatin, a potent inhibitor of insulin and glucagon secretion, was infused for 5 h into healthy human subjects, maturity-onset diabetes, juvenile-onset diabetics, and normal dogs. Infusion of somatostatin resulted in an increase in serum potassium (0.5-0.6 meq/liter) in normal subjects and maturity-onset diabetics, but not in juvenile-onset diabetics despite equivalent reductions in plasma glucagon in all three groups. A similar rise in serum potassium was observed in normal conscious dogs given somatostatin and was reversed by insulin replacement. Urinary excretion of potassium was unaffected by somatostatin. In dogs given intravenous potassium chloride in doses (0.375 meq/kg per h) which do not alter basal insulin levels, the rise in serum potassium (0.6 meq/liter in controls) increased 100% when somatostatin was administered together with the KCl infusion. Addition of replacement doses of insulin to the somatostatin infusion resulted in increments in serum potassium which were comparable to infusion of KCl alone. Urinary potassium excretion rose after KCl administration and was unchanged by the addition of somatostatin. Serum sodium concentration was unaffected by somatostatin administration in both the human and dog studies. However, urinary sodium excretion displayed a biphasic response falling by 20-60% within the first 2 h of somatostatin administration and then rising to values 50-80% above basal levels at 3-4 h. Inulin and p-aminohippurate clearances were unaffected by somatostatin. It is concluded that (a) potassium homeostasis is influenced by basal insulin levels in the absence of which serum potassium concentration rises and potassium tolerance declines; (b) this effect of insulin is mediated via extrarenal mechanisms of potassium disposal; (c) somatostatin has a biphasic effect on urinary sodium secretion, the mechanism of which remains to be established.

Comparison of the metabolic effects of recombinant human insulin-like growth factor-I and insulin. Dose-response relationships in healthy young and middle-aged adults.

The actions of recombinant human insulin-like growth factor-I (rhIGF-I) and insulin were compared in 21 healthy young (24 +/- 1 yr) and 14 healthy middle-aged (48 +/- 2 yr) subjects during 3-h paired euglycemic clamp studies using one of three doses (rhIGF-I 0.2, 0.4, and 0.8 micrograms/kg.min and insulin 0.2, 0.4, and 0.8 mU/kg.min, doses chosen to produce equivalent increases in glucose uptake). In younger subjects, rhIGF-I infusions suppressed insulin by 19-33%, C-peptide by 47-59% and glucagon by 33-47% (all, P < 0.02). The suppression of C-peptide was less pronounced with insulin than with rhIGF-I (P < 0.007). The metabolic responses to rhIGF-I and insulin were remarkably similar: not only did both hormones increase glucose uptake and oxidation in a nearly identical fashion, but they also produced similar suppression of glucose production, free fatty acid levels, and fat oxidation rates. In contrast, rhIGF-I had a more pronounced amino acid-lowering effect than did insulin (P < 0.004). In middle-aged subjects, basal IGF-I levels were 44% lower (P < 0.0001) whereas basal insulin and C-peptide were 20-25% higher than in younger subjects. Age did not alter the response to rhIGF-I. However, insulin-induced stimulation of glucose uptake was blunted in older subjects (P = 0.05). Our data suggest that absolute IGF-I and relative insulin deficiency contribute to adverse metabolic changes seen in middle age.

Interstitial fluid concentrations of glycerol, glucose, and amino acids in human quadricep muscle and adipose tissue. Evidence for significant lipolysis in skeletal muscle.

To determine the relationship between circulating metabolic fuels and their local concentrations in peripheral tissues we measured glycerol, glucose, and amino acids by microdialysis in muscle and adipose interstitium of 10 fasted, nonobese human subjects during (a) baseline, (b) euglycemic hyperinsulinemia (3 mU/kg per min for 3 h) and, (c) local norepinephrine reuptake blockade (NOR). At baseline, interstitial glycerol was strikingly higher (P < 0.0001) in muscle (3710 microM) and adipose tissue (2760 microM) compared with plasma (87 microM), whereas interstitial glucose (muscle 3.3, fat 3.6 mM) was lower (P < 0.01) than plasma levels (4.8 mM). Taurine, glutamine, and alanine levels were higher in muscle than in adipose or plasma (P < 0.05). Euglycemic hyperinsulinemia did not affect interstitial glucose, but induced a fall in plasma glycerol and amino acids paralleled by similar changes in the interstitium of both tissues. Local NOR provoked a fivefold increase in glycerol (P < 0.001) and twofold increase in norepinephrine (P < 0.01) in both muscle and adipose tissues. To conclude, interstitial substrate levels in human skeletal muscle and adipose tissue differ substantially from those in the circulation and this disparity is most pronounced for glycerol which is raised in muscle as well as adipose tissue. In muscle, insulin suppressed and NOR increased interstitial glycerol concentrations. Our data suggest unexpectedly high rates of intramuscular lipolysis in humans that may play an important role in fuel metabolism.

Psychosocial predictors and moderators of weight management programme outcomes in ethnically diverse obese youth.

BACKGROUND: An important area of research in childhood obesity is the identification of factors that predict or moderate the responses to obesity intervention programmes, yet few studies have examined the impact of self-esteem and family functioning on obesity treatment outcomes. OBJECTIVES: We sought to determine whether baseline self-esteem and family functioning predicted or moderated childhood obesity intervention outcomes at 6 months. METHODS: From 2009 to 2011, seventy-five 10-16 year old, racially/ethnically diverse obese youths with abnormal glucose tolerance were randomized to 6 months of an intensive family-based obesity lifestyle intervention (Bright Bodies) or routine outpatient Clinic Care. We examined youth self-concept, parent-rated family functioning and 6-month outcomes (youths' glucose tolerance, weight, body mass index and percent fat). We set the significance threshold as P ≤ 0.05 for moderator and predictor analyzes. RESULTS: Having poor family functioning and self-concept scores indicating high anxiety and low self-esteem at baseline predicted poor 6-month outcomes overall (Bright Bodies and Clinic Care groups combined). Additionally, baseline self-esteem and family functioning moderated treatment effects such that Bright Bodies outperformed Clinic Care in youths with low self-esteem and poorly functioning families, whereas youths with high self-esteem and high-functioning families did similarly well with either intervention. DISCUSSION: Our findings suggest intensive family-based lifestyle programmes are particularly beneficial for youth with low self-esteem and poorly functioning families.

Effect of intensive insulin therapy on glycemic thresholds for counterregulatory hormone release.

To evaluate the effect of strict glycemic control of insulin-dependent diabetes mellitus (IDDM) on the plasma glucose threshold initiating counterregulatory hormone responses to hypoglycemia, we used the glucose clamp technique to produce a standardized gradual glucose decline from 90 to 40 mg/dl in seven young IDDM patients before and after 2-6 mo of intensified insulin therapy. Before intensive therapy [hemoglobin A1 (HbA1) 9.6 +/- 1.1%], epinephrine responses were triggered at a higher plasma glucose level (67 +/- 4 mg/dl) than in normal control subjects (56 +/- 1 mg/dl, P less than .05), and clinical symptoms of hypoglycemia appeared at glucose levels of 50-60 mg/dl. After intensive therapy (HbA1 7.1 +/- 0.7%), the glucose threshold for epinephrine release consistently declined to values (46 +/- 2 mg/dl) below normal (P less than .01). Furthermore, epinephrine concentrations were markedly reduced at each hypoglycemic level, and a greater hypoglycemic stimulus was required to elicit symptoms. The glucose threshold stimulating release of growth hormone also significantly declined after intensive therapy. We conclude that strict glycemic control of IDDM lowers the plasma glucose level required to generate epinephrine release during hypoglycemia. This may diminish patient recognition of moderate hypoglycemia and increase the risk of severe hypoglycemia in intensively treated IDDM.

Loss of potentiating effect of hypoglycemia on the glucagon response to hyperaminoacidemia in IDDM.

IDDM subjects lose the ability to release glucagon during hypoglycemia. Because replacement of basal levels of amino acids enhances the glucagon response to hypoglycemia in healthy subjects, we tested whether raising amino acid levels during hypoglycemia could reverse the defective alpha-cell response in IDDM patients. For this purpose, 11 IDDM patients (HbA1 9.4 +/- 0.6%) and 8 healthy, nondiabetic subjects received two hypoglycemic insulin clamp studies (0.8 mU.kg-1 x min-1) in which plasma glucose was clamped at 55 mg/dl (3.08 mM) for 180 min. During one of the studies, an infusion of amino acids was superimposed between 120 and 180 min (0.3 g.kg-1 x h-1). This dose of amino acids had a small effect on plasma glucagon levels during euglycemic hyperinsulinemia that was comparable in normal and IDDM subjects. In healthy control subjects, plasma glucagon rose by 80% during the initial hypoglycemic phase of the study. The addition of amino acids produced a further sharp (200-250 ng/L, P < 0.02) rise in plasma glucagon, such a change did not occur in the absence of amino acids. In contrast, plasma glucagon in IDDM patients failed to increase during hypoglycemia alone and rose by only 40-50 ng/L (P < 0.05 vs. controls) when amino acid infusion was superimposed, even though plasma amino acid levels rose to the same extent in IDDM and control subjects. More importantly, the rise in glucagon produced by amino acids was comparable during hypoglycemic and euglycemic hyperinsulinemia in the IDDM patients, results strikingly different from those observed in nondiabetic control subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Rate of glucose fall does not affect counterregulatory hormone responses to hypoglycemia in normal and diabetic humans.

To test the hypothesis that variations in rate of glucose fall influence counterregulatory hormone responses to hypoglycemia, we have modified the glucose-clamp technique to provide a reproducible hypoglycemic stimulus in normal and type I diabetic subjects that varied only in the rate of glucose fall. Responsive elevations in plasma epinephrine and norepinephrine and in growth hormone, glucagon, and cortisol were not significantly affected by a ninefold change in the rate at which plasma glucose was lowered from 83 +/- 1 to 50 +/- 1 mg/dl in normal subjects. Similarly, wide variation in the rate of fall produced no substantive differences in counterregulatory hormone responses to hypoglycemia in diabetic subjects. The plasma glucose threshold at which epinephrine release began, determined from the slow-fall studies, was 63 +/- 3 mg/dl in normal subjects but exhibited a wide range (48-74 mg/dl). Similar values were found in the diabetics. Thresholds for growth hormone, cortisol, and glucagon were slightly lower, ranging from 45 to 68 mg/dl in the normals. Our data suggest that counterregulatory hormone responses to hypoglycemia are triggered by the glucose level per se and not by its rate of fall. Furthermore, individual differences in glucose thresholds for epinephrine release may contribute to variations in the glucose level associated with hypoglycemic symptoms.

Defective free-fatty acid and oxidative glucose metabolism in IDDM during hypoglycemia. Influence of glycemic control.

To examine the impact of diabetes and its treatment on plasma free-fatty acid (FFA) and oxidative fuel metabolism during hypoglycemia, we combined indirect calorimetry with [3-3H]glucose during a 4-h low-dose insulin infusion (plasma insulin approximately 2-fold above basal) in six poorly controlled and nine well-controlled insulin-dependent diabetes mellitus (IDDM) patients and in six healthy subjects. Diabetic subjects received insulin overnight to maintain euglycemia before study. Although free-insulin levels and counterregulatory hormone responses were similar, the plasma glucose fall was more pronounced in well-controlled diabetic subjects. In well-controlled diabetic and healthy subjects, the small increment in insulin rapidly suppressed plasma FFA and fat oxidation by approximately 50% and stimulated carbohydrate oxidation by approximately 80%. In contrast, plasma FFA levels did not fall in poorly controlled diabetic subjects, and glucose oxidation was not stimulated. To determine whether this resistance to the antilipolytic effect of insulin occurs in the absence of hypoglycemic counterregulation, we used a sequential low-dose euglycemic insulin clamp (0.2, 0.3, and 0.5 mU.kg-1.min-1). In healthy subjects, plasma FFA was nearly maximally suppressed at the lowest insulin dose. In contrast, plasma FFA remained persistently elevated in poorly controlled diabetic subjects at each insulin dose. However, the insulin dose-response curve for suppression of plasma FFA was near normal in well-controlled subjects. We conclude that poorly controlled IDDM diabetic patients are resistant to the antilipolytic effects of insulin and show impaired stimulation of glucose oxidation during insulin-induced hypoglycemia. Amelioration of these defects in well-controlled patients may be another factor contributing to the higher risk of hypoglycemia during intensified insulin therapy.

Counterregulation in peripheral tissues: effect of systemic hypoglycemia on levels of substrates and catecholamines in human skeletal muscle and adipose tissue.

We used microdialysis to distinguish the effects of hyperinsulinemia and hypoglycemia on glucose, gluconeogenic substrate, and catecholamine levels in adipose and muscle extracellular fluid (ECF). Ten lean humans (six males and four females) were studied during baseline and hyperinsulinemic (3 mU x kg-1 x min-1 for 3 h) euglycemia (5.0 mmol/l) and hypoglycemia (2.8 mmol/l). In muscle and adipose, basal ECF glucose was lower (muscle, 3.5 +/- 0.2 mmol/l; adipose tissue, 3.3 +/- 0.2 mmol/l) and lactate was higher (muscle, 2.2 +/- 0.2 mmol/l; adipose, 1.5 +/- 0.3 mmol/l) than respective plasma values (glucose, 4.9 +/- 0.1 mmol/l; lactate, 0.7 +/- 0.1 mmol/l), whereas alanine was higher in muscle ECF (379 +/- 22 micromol/l) than adipose tissue (306 +/- 22 micromol/l) and plasma (273 +/- 33 micromol/l). Plasma catecholamines (unchanged during euglycemia) rose during hypoglycemia with epinephrine, increasing approximately fivefold more than norepinephrine. In contrast, the hypoglycemia-induced increments in muscle dialysate norepinephrine and epinephrine were similar, suggesting local generation of norepinephrine. Compared with euglycemia, hypoglycemia produced a greater increase in lactate and a smaller reduction in alanine in muscle ECF, whereas hypoglycemia caused a greater relative fall in ECF glucose concentrations in muscle (72 +/- 16%) and adipose tissue (69 +/- 9%) than in plasma (42 +/- 3%) (P < 0.05). We conclude that hypoglycemia increases the generation of norepinephrine and gluconeogenic substrates in key target tissues, while increasing the plasma-tissue concentration gradient for glucose. These changes suggest the stimulation of glucose extraction by peripheral tissues, despite systemic counterregulatory hormone release and local sympathetic activation.

Conference on insulin pump therapy in diabetes. Multicenter study of effect on microvascular disease. Origin and design of the Kroc Collaborative Study.

Although the benefits of metabolic intervention on the microvascular complications of diabetes mellitus remain unproven, it is generally assumed though not proven that prognosis in terms of blindness and renal failure will reflect the long-term glycemic response to therapy. Treatment goals however remain poorly defined. Costs and hazards of achieving near-normoglycemia in insulin-dependent diabetes mellitus (IDDM) are major. A multicenter trial was proposed to test the hypothesis that in IDDM two levels of mean glycemia, sufficiently separated to examine the control/complications relationship, could be maintained by the six collaborating centers, using randomized patient allocation to conventional insulin therapy (CIT) and continuous subcutaneous insulin infusion (CSII) as the alternative treatment modalities. Methods of maintaining and monitoring metabolic control and of assessing renal and retinal responses were to be applied, evaluated, and possibly improved. All clinics shared a common experimental protocol, which received ethical approval at each treatment center. Retinal assessment facilities were provided by the Fundus Photograph Reading Center at the University of Wisconsin in Madison, and at the Diabetic Retinopathy Department, Royal Postgraduate Medical School, Hammersmith, United Kingdom. The Central Biochemistry Laboratory was at the University of Newcastle, United Kingdom. Collaborators agreed on policy for recruitment, baseline assessment, and randomization of patients with IDDM, complicated by early microvascular disease. CIT took the form of the unchanged prestudy regimen; glycemic goals were set for CSII and their achievement based on inpatient and outpatient sampling of plasma glucose. Glycosylated hemoglobin was measured, retinal abnormalities recorded photographically, and urinary albumin excretion quantitated at baseline, 4, and 8 mo in all patients.(ABSTRACT TRUNCATED AT 250 WORDS)