Insulin resistance in multiple tissues in patients with type 1 diabetes mellitus on long-term continuous subcutaneous insulin infusion therapy.

BACKGROUND: The aim of this study was to determine whether insulin resistance is present in lean patients with uncomplicated type 1 diabetes mellitus on long-term continuous subcutaneous insulin infusion (CSII), compared with matched healthy controls. METHODS: We studied eight patients (four men and four women) with type 1 diabetes mellitus on continuous subcutaneous insulin infusion and eight healthy controls, matched for age, gender and body mass index. Insulin sensitivity was measured by hyperinsulinemic euglycemic clamp studies with infusion of [6,6-(2) H(2)] glucose. RESULTS: Endogenous glucose production did not differ in the basal state between patients and controls. However, endogenous glucose production was less suppressed during clamp conditions in patients compared with controls (64% vs 79%, p = 0.01), indicating decreased hepatic insulin sensitivity. During the clamp study, glucose disposal rate was ~38% lower in patients compared with controls (24.4 ± 2.5 vs 39.7 ± 5.6 µmol/kgLBM/min, p = 0.04). Accordingly, the rate of infusion of glucose was ~51% lower in patients (17.7 ± 2.8 vs 39.7 ± 5.7 µmol/kgLBM/min, p = 0.02). Finally, non-esterified fatty acids levels were ~2.5 times higher in patients during steady state clamp conditions (150 ± 26 vs 58 ± 4 pmol/L, p = 0.01), reflecting decreased insulin sensitivity of lipolysis. CONCLUSIONS: Insulin resistance is a prominent feature of lean patients with type 1 diabetes mellitus, despite long term and stable treatment with continuous subcutaneous insulin infusion. Insulin resistance in type 1 diabetes involves both lipolysis, hepatic and peripheral glucose metabolism.

Cognitive performance, psychological well-being, and brain magnetic resonance imaging in older patients with type 1 diabetes.

Modest cognitive impairment has been reported in young-adult patients with type 1 diabetes. In older patients with type 2 diabetes, cognitive impairments are more pronounced, which might be due to age but also to differential effects of type 1 diabetes and type 2 diabetes on the brain. This study therefore assessed cognitive performance and magnetic resonance imaging (MRI) of the brain in older type 1 diabetic patients. Forty type 1 diabetic patients (age >50 years) and 40 age-matched control subjects were included. Neuropsychological assessment included all major cognitive domains, and psychological well-being was assessed with questionnaires. Atrophy, white-matter abnormalities, and infarcts were rated on MRI scans. Type 1 diabetic patients performed slightly (effect sizes <0.4) worse on cognitive tasks, but only "speed of information processing" reached statistical significance. No significant between-group differences were found on any of the MRI parameters. Type 1 diabetic patients tended to report more cognitive and depressive problems than control subjects, but this did not correlate with the performance on cognitive tests. We conclude that cognition in older type 1 diabetic patients is only mildly disturbed. Chronic exposure to hyperglycemia is in itself, even at older age, apparently not sufficient to have considerable impact on the brain.

Determinants of daily insulin use in Type 1 diabetes.

OBJECTIVE: Insulin need for a given degree of glucose control varies markedly among individuals. We examined which factors determine daily insulin use in patients with Type 1 diabetes. METHODS: A cross-sectional study was performed in 416 patients. Clinical parameters, medication use, physical activity, smoking, alcohol consumption, and laboratory parameters were determined. RESULTS: Body mass index and waist circumference were positively related to daily insulin use (2.3 U/kg/m(2), 95% CI=1.9-2.7 and 0.8 U/cm, 95% CI=0.6-0.9, adjusted for age and sex). Age, female sex, and duration of diabetes were inversely related to daily insulin dose. There was an increase of 3.6 U of insulin per mmol/l triglycerides (95% CI=1.04-6.2) and a decrease of 5.9 U of insulin per mmol/l high-density lipoprotein cholesterol (95% CI=-10.0 to -1.8), adjusted for age, sex, and weight. For blood pressure-lowering drugs, the strongest relation was found for thiazide diuretics (difference of 7.1 U insulin/day, 95% CI=0.2-14.2, adjusted for age, sex, and weight). The use of an insulin pump and physical activity were related to lower daily insulin need: -8.7 U/day (95% CI=-11.8 to -5.5) and -1.7 U/day per activity score unit (95% CI=-3.2 to -0.2), respectively, adjusted for age, sex, and weight. Smoking was related to an increased need of 5.3 U/day (95% CI=1.5-9.0), adjusted for age, sex, and weight. CONCLUSIONS: Our results show that components of the metabolic syndrome are positively related to daily insulin use. Also, decreased physical activity, smoking, and the use of blood pressure-lowering drugs, which influence insulin sensitivity, are associated with an increased insulin need. These findings suggest that the presence of insulin resistance in Type 1 diabetes or "double diabetes" plays a key role in determining daily insulin need.

High cumulative insulin exposure: a risk factor of atherosclerosis in type 1 diabetes?

BACKGROUND: Since insulin therapy might have an atherogenic effect, we studied the relationship between cumulative insulin dose and atherosclerosis in type 1 diabetes. We have focused on patients with type 1 diabetes instead of type 2 diabetes to minimise the effect of insulin resistance as a potential confounder. METHODS: An observational study was performed in 215 subjects with type 1 diabetes treated with multiple insulin injection therapy. Atherosclerosis was assessed by measurement of carotid intima-media thickness (CIMT). RESULTS: The cumulative dose of regular insulin showed a positive and significant relation with CIMT: increase of 21 microm in CIMT per S.D. of insulin use (95% CI: 8-35 adjusted for gender and age), which remained unchanged after adjustment for duration of diabetes, HbA1c, BMI, pulse pressure, physical activity and carotid lumen diameter. A similar relation was found for intermediate-acting insulin: 15.5 microm per S.D. (2-29), which was no longer present after further adjustment. CONCLUSIONS: These findings provide evidence that a high cumulative dose of regular insulin is a risk factor for atherosclerosis.

Vesiculopustular dermatosis: an uncommon side-effect of liraglutide?

Liraglutide is a GLP-1 receptor agonist, a novel medication for type 2 diabetes. We describe a case of pustules in a patient recently started on liraglutide. Common side effects of liraglutide are gastrointestinal disorders. Skin and tissue reactions are less well-known side effects. Liraglutide could be the cause of skin eruptions in this patient, possibly by immunogenicity.

Multicenter user evaluation of ACCU-CHEK® Combo, an integrated system for continuous subcutaneous insulin infusion.

BACKGROUND: The aim of this study was to evaluate a newly developed system for insulin delivery incorporating a multifunctional blood glucose meter and a remotely controlled insulin pump (ACCU-CHEK® Combo system) in established pump users with type 1 diabetes. The technology was assessed both from device performance and subject usability perspectives. METHOD: A multicenter, prospective, single group study was carried out in five centers in the Netherlands and four centers in the United Kingdom for more than 6 months. The study was divided into two phases: Phase 1 (4 weeks) for device validation purposes and phase 2 (22 weeks) to observe the impact of the system on metabolic control, patient satisfaction [using the Diabetes Treatment Satisfaction Questionnaire (DTSQ)] and device safety. RESULTS: Eighty subjects completed the planned study period. There were no unexpected device errors. Treatment satisfaction was high at baseline and further increased to study end (DTSQ change version: sum score, 10.6±7.2; scale score range, -18 to +18, p<0.0001). Hemoglobin A1c improved continuously over time, from 7.9% (±0.9%) to 7.7% (±0.8%) at month 3 (p<0.001) and 7.6% (±0.8%) at month 6 (p<0.0001). The frequency of severe hypoglycemia was 0.08 per patient years. There was no case of ketoacidosis. CONCLUSIONS: The new system was evaluated by experienced continuous subcutaneous insulin infusion users as safe in daily practice and associated with favorable treatment satisfaction and a modest improvement in glycemic control.

Partial sleep restriction decreases insulin sensitivity in type 1 diabetes.

OBJECTIVE: Sleep restriction results in decreased insulin sensitivity and glucose tolerance in healthy subjects. We hypothesized that sleep duration is also a determinant of insulin sensitivity in patients with type 1 diabetes. RESEARCH DESIGN AND METHODS: We studied seven patients (three men, four women) with type 1 diabetes: mean age 44 +/- 7 years, BMI 23.5 +/- 0.9 kg/m(2), and A1C 7.6 +/- 0.3%. They were studied once after a night of normal sleep duration and once after a night of only 4 h of sleep. Sleep characteristics were assessed by polysomnography. Insulin sensitivity was measured by hyperinsulinemic euglycemic clamp studies with an infusion of [6,6-(2)H(2)]glucose. RESULTS Sleep duration was shorter in the night with sleep restriction than in the unrestricted night (469 +/- 8.5 vs. 222 +/- 7.1 min, P = 0.02). Sleep restriction did not affect basal levels of glucose, nonesterified fatty acids (NEFAs), or endogenous glucose production. Endogenous glucose production during the hyperinsulinemic clamp was not altered during the night of sleep restriction compared with the night of unrestricted sleep (6.2 +/- 0.8 vs. 6.9 +/- 0.6 micromol x kg lean body mass(-1) x min(-1), NS). In contrast, sleep restriction decreased the glucose disposal rate during the clamp (25.5 +/- 2.6 vs. 22.0 +/- 2.1 micromol x kg lean body mass(-1) x min(-1), P = 0.04), reflecting decreased peripheral insulin sensitivity. Accordingly, sleep restriction decreased the rate of glucose infusion by approximately 21% (P = 0.04). Sleep restriction did not alter plasma NEFA levels during the clamp (143 +/- 29 vs. 133 +/- 29 micromol/l, NS). CONCLUSIONS: Partial sleep deprivation during a single night induces peripheral insulin resistance in these seven patients with type 1 diabetes. Therefore, sleep duration is a determinant of insulin sensitivity in patients with type 1 diabetes.

Functional brain connectivity and neurocognitive functioning in patients with long-standing type 1 diabetes with and without microvascular complications: a magnetoencephalography study.

OBJECTIVE: Hyperglycemia-associated microvascular disease may underlie changes in cerebral functioning and cognitive performance in patients with type 1 diabetes. Functional connectivity, an indicator of functional interactions and information exchange between brain regions, provides a measure of cerebral functioning. This study addresses functional connectivity and cognition in type 1 diabetic patients with and without proliferative retinopathy, relative to healthy control subjects, using magnetoencephalography. RESEARCH DESIGN AND METHODS: Fluctuations in magnetic field at scalp for Delta, theta, lower and upper alpha, beta, and lower and upper gamma frequency bands were measured using magnetoencephalography. Synchronization likelihood, a measure of functional connectivity, was computed. Using neuropsychological tests, cognitive functioning was assessed and its associations with functional connectivity were determined. RESULTS: Compared with control subjects, type 1 diabetic patients performed poorer on general cognitive ability, information processing speed, and motor speed, irrespective of their microvascular complication status. Functional connectivity, however, was lowest for type 1 diabetic patients with retinopathy, compared with type 1 diabetic patients without microvascular complications and control subjects, whereas type 1 diabetic patients without microvascular complications showed an increase relative to control subjects. Positive associations were found between functional connectivity and executive functioning, memory, information processing speed, motor speed, and attention. CONCLUSIONS: Compared with healthy control subjects, functional connectivity and cognition differed in type 1 diabetic patients irrespective of microvascular complication status, indicating that chronic hyperglycemia, among other factors, may negatively affect brain functioning even before microvascular damage becomes manifest. The association found between synchronization likelihood and cognition suggests functional connectivity plays a significant role in cognitive functioning.