No evidence of tachyphylaxis for insulinotropic actions of glucose-dependent insulinotropic polypeptide (GIP) in subjects with type 2 diabetes, their first-degree relatives, or in healthy subjects.

BACKGROUND, AIMS: In patients with type 2 diabetes, the lost insulinotropic effect of the incretin hormone glucose-dependent insulinotropic polypeptide (GIP) is more apparent after continuous versus bolus administration. To test whether the difference might be explained by rapid tachyphylaxis in response to elevated concentrations of GIP, and whether patients with type 2 diabetes and their relatives are more susceptible to tachyphylaxis than healthy subjects. PATIENTS AND METHODS: In a two-way crossover design, insulinotropic responses to repeated bolus injection (50 pmol/kg body weight at 30 and 120 min) and continuous infusion of GIP (2 pmol.kg-1.min-1 from 30 to 180 min) under hyperglycaemic clamp conditions (8.5 mmol/l) was compared in age- gender- and weight-matched patients with type 2 diabetes, first degree relatives of such patients, and healthy subjects. RESULTS: Insulin secretory responses to the first and second GIP bolus were not significantly different in any of the subject groups. Subjects with type 2 diabetes had a significant relative impairment versus healthy subjects with continuous (C-peptide, -13.2 %, p < 0.05), but not with repeated bolus administration of GIP (+11.1 %, n.s.). First-degree relatives tended to hyper-secrete insulin with bolus or continuous administrations of GIP. CONCLUSIONS: Rapid tachyphylaxis in response to continuous exposure to slightly supraphysiological concentrations of GIP does not explain the reduced insulinotropic response to GIP infusions in patients with type 2 diabetes or their first-degree relatives.

Glucagon-like peptide 1 (GLP-1).

BACKGROUND: The glucagon-like peptide-1 (GLP-1) is a multifaceted hormone with broad pharmacological potential. Among the numerous metabolic effects of GLP-1 are the glucose-dependent stimulation of insulin secretion, decrease of gastric emptying, inhibition of food intake, increase of natriuresis and diuresis, and modulation of rodent ß-cell proliferation. GLP-1 also has cardio- and neuroprotective effects, decreases inflammation and apoptosis, and has implications for learning and memory, reward behavior, and palatability. Biochemically modified for enhanced potency and sustained action, GLP-1 receptor agonists are successfully in clinical use for the treatment of type-2 diabetes, and several GLP-1-based pharmacotherapies are in clinical evaluation for the treatment of obesity. SCOPE OF REVIEW: In this review, we provide a detailed overview on the multifaceted nature of GLP-1 and its pharmacology and discuss its therapeutic implications on various diseases. MAJOR CONCLUSIONS: Since its discovery, GLP-1 has emerged as a pleiotropic hormone with a myriad of metabolic functions that go well beyond its classical identification as an incretin hormone. The numerous beneficial effects of GLP-1 render this hormone an interesting candidate for the development of pharmacotherapies to treat obesity, diabetes, and neurodegenerative disorders.

A case series of verrucae vulgares mimicking hyperkeratosis in individuals with diabetic foot ulcers.

BACKGROUND: Diabetic foot ulcers are a common complication in the advanced stages of diabetes mellitus. Certain lesions may be refractory to usual treatments with prolonged healing. In these cases, differential diagnoses to classical ulcers should be considered. Although plantar warts are a common and easy-to-diagnose finding in the general population, diagnosis can be challenging in people with diabetic foot ulcers, as they mimic hyperkeratosis in these people. CASE REPORT: We report seven cases of people with diabetic foot ulcers and verrucae vulgares mimicking treatment-refractory hyperkeratosis, presenting to our centre between 2014 and 2016. Diagnosis was aided by the clinical presentation, followed by dermoscopy and punch biopsy. Treatment included topical application of 5-fluoruracil and salicylic acid (four people), cryotherapy (three people) and surgical excision (three people), all in combination with local pressure offloading. In five people, the verrucae were completely removed after a mean treatment period of 9.4 months; two individuals were lost to follow-up. CONCLUSION: Verrucae may be more common in people with diabetic foot lesions and polyneuropathy than generally assumed. Typical findings include small, pinhead-sized bleedings within and surrounding hyperkeratous lesions. These findings should alert the clinician for the potential presence of a verruca. In such cases, biopsy should be performed to enable specific diagnosis and treatment.

[Recurrent hypoglycemia due to an occult insulinoma]. / Okkultes Insulinom als Ursache rezidivierender Hypoglykämien.

A 64-year-old woman presented with a history of recurrent hypoglycemia. A prolonged fasting test revealed an increased "amended" insulin-glucose ratio. Transabdominal ultrasound (US), computed tomography (CT) scan, and magnetic resonance imaging (MRI) did not show abnormal results. An insulinoma was suspected based on a contrast-enhanced endoscopic US examination as well as a (68)gallium-DOTA-exendin-4 positron-emission tomography (PET)/CT. The diagnosis of an insulinoma was confirmed histologically after surgical removal of the tumor. Hypoglycemia did not occur during the postoperative period. The prolonged fasting test is the gold standard for the diagnosis of an insulinoma. Novel imaging procedures, such as contrast-enhanced endoscopic US or (68)gallium-DOTA-exendin-4 PET/CT are valuable additions to the diagnostic workup.

Fasting C-peptide and Related Parameters Characterizing Insulin Secretory Capacity for Correctly Classifying Diabetes Type and for Predicting Insulin Requirement in Patients with Type 2 Diabetes.

BACKGROUND/AIMS: C-peptide allows estimation of insulin secretion even in the presence of insulin treatment. C-peptide may be suitable for the differential diagnosis of type 1 and type 2 diabetes, and, within type 2 diabetes, of insulin-requiring vs. non-insulin-requiring patients. Relating C-peptide concentrations to ambient glucose levels might improve its diagnostic potential. PATIENTS/METHODS: The diagnostic value (a) fasting C-peptide, (b) C-peptide/glucose ratios, and (c) the HOMA-ßC-peptide-index for predicting a diagnosis of type 1 (vs. type 2) diabetes were assessed. SETTING: Specialised hospital for the care of diabetic patients (inpatient treatment). 303 patients with type 1 diabetes and 841 patients with type 2 diabetes. MAIN OUTCOME MEASURE: Odds ratios and 95% confidence intervals for a clinical diagnosis of type 1 diabetes or for insulin treatment by deciles of (a) fasting C-peptide, (b) C-peptide/glucose ratios, and (c) HOMA-ßC-peptide-index. RESULTS: Low C-peptide concentrations were associated with a high odds ratio for type 1 diabetes and vice versa (p<0.0001). Concentrations of 0.13-0.36 nmol/l did not discriminate. C-peptide/glucose ratios or HOMA-ßC-Peptide did not perform better. The ability of all 3 parameters to predict the necessity for insulin treatment within the population of type 2-diabetic patients was low. CONCLUSIONS: Fasting C-peptide and derived parameters help to differentiate type 1 from type 2 diabetes, but there is a range of C-peptide concentrations that does not help discriminate. Relating C-peptide to glucose did not improve diagnostic accuracy. C-peptide does not help predicting a need for insulin treatment in patients with type 2 diabetes.

Impact of diabetes duration on achieved reductions in glycated haemoglobin, fasting plasma glucose and body weight with liraglutide treatment for up to 28 weeks: a meta-analysis of seven phase III trials.

This meta-analysis of seven randomized, placebo-controlled studies (total 3222 patients) evaluated whether type 2 diabetes (T2D) duration affects the changes in blood glucose control and body weight that can be achieved with liraglutide and placebo. With liraglutide 1.2 mg, shorter diabetes duration was associated with a significantly greater, but clinically non-relevant, difference in glycated haemoglobin (HbA1c) reduction (p < 0.05), i.e. a 0.18% (1.96 mmol/mol) reduction in HbA1c per 10 years shorter diabetes duration. With liraglutide 1.8 mg, shorter diabetes duration was associated with a small but statistically significant trend for greater fasting plasma glucose (FPG) reduction (p < 0.05), i.e. a 0.38 mmol/l reduction in FPG per 10 years shorter diabetes duration. Neither the liraglutide 1.8 mg nor placebo results showed a significant association between HbA1c and diabetes duration and neither the liraglutide 1.2 mg nor placebo results showed a significant association between FPG and diabetes duration. Likewise, neither liraglutide nor placebo showed a significant association between change in weight and diabetes duration. These results suggest diabetes duration has a clinically negligible effect on achievable blood glucose control and weight outcomes with liraglutide and placebo in patients with T2D.

Improvement in glycated haemoglobin evaluated by baseline body mass index: a meta-analysis of the liraglutide phase III clinical trial programme.

In the liraglutide clinical trial programme, liraglutide 1.2 and 1.8 mg were found to effectively lower glycated haemoglobin (HbA1c) in patients with type 2 diabetes (T2D). It is unknown whether baseline body mass index (BMI) is a predictor of change in HbA1c observed during a clinical trial with liraglutide or placebo treatment. The present meta-analysis of patient-level data, using pooled data from seven phase III trials [LEAD-1-6 and the liraglutide versus sitagliptin trial (LIRA-DPP-4)] for liraglutide 1.2, 1.8 mg and placebo (n = 3222), identified no significant correlation between baseline BMI (<20 kg/m(2) up to 45 kg/m(2) ) and HbA1c reduction for placebo or liraglutide 1.2 mg, and a modest, clinically non-relevant, association for liraglutide 1.8 mg [-0.010 (95% confidence interval -0.020, -0.001)], whereby a 10 kg/m(2) increase in baseline BMI corresponded to 0.10%-point (1.1 mmol/mol) greater HbA1c reduction. In summary, reductions in HbA1c obtained during clinical trials with liraglutide or placebo treatment were independent of baseline BMI.

Efficacy and safety of liraglutide versus placebo added to basal insulin analogues (with or without metformin) in patients with type 2 diabetes: a randomized, placebo-controlled trial.

AIM: To confirm the superiority, compared with placebo, of adding liraglutide to pre-existing basal insulin analogue ± metformin in adults with inadequately controlled type 2 diabetes [glycated haemoglobin (HbA1c) 7.0-10.0% (53-86 mmol/mol)]. METHODS: In this 26-week, double-blind, parallel-group study, conducted in clinics or hospitals, 451 subjects were randomized 1 : 1 to once-daily liraglutide 1.8 mg (dose escalated from 0.6 and 1.2 mg/day, respectively, for 1 week each; n = 226) or placebo (n = 225) added to their pre-existing basal insulin analogue (≥20 U/day) ± metformin (≥1500 mg/day). After randomization, insulin adjustments above the pre-study dose were not allowed. The primary endpoint was HbA1c change. RESULTS: After 26 weeks, HbA1c decreased more with liraglutide [-1.3% (-14.2 mmol/mol)] than with placebo [-0.1% (-1.2 mmol/mol); p < 0.0001]. More subjects on liraglutide reached HbA1c targets: <7.0% (59% vs 14%; p < 0.0001) and ≤6.5% (43% vs 4%; p < 0.0001) using slightly less insulin (35.8 IU vs 40.1 IU). Greater decreases from baseline (estimated treatment differences vs placebo; p < 0.0001) occurred in fasting plasma glucose (-1.3 mmol/l), seven-point glucose profiles (-1.6 mmol/l), body weight (-3.1 kg) and systolic blood pressure (-5.0 mmHg). Transient gastrointestinal adverse events (nausea: 22.2% vs 3.1%) and minor hypoglycaemia (18.2% vs 12.4%) were more frequent with liraglutide than placebo, and pulse increased (4.5 beats/min) compared with placebo. No severe hypoglycaemia or pancreatitis occurred. CONCLUSIONS: Adding liraglutide to a basal insulin analogue ± metformin significantly improved glycaemic control, body weight and systolic blood pressure compared with placebo. Typical gastrointestinal symptoms and minor hypoglycaemia were more frequent with liraglutide.

Improved glucose control with reduced hypoglycaemic risk when linagliptin is added to basal insulin in elderly patients with type 2 diabetes.

AIM: To assess the efficacy, hypoglycaemia risk and other safety markers of linagliptin as an additional therapy in older patients (aged ≥70 years) inadequately controlled with basal insulin. METHODS: A prespecified safety analysis from the linagliptin trials programme was carried out to explore the hypoglycaemia risk when linagliptin was added to background basal insulin therapy in elderly patients (≥70 years). To do this, two eligible, randomized, placebo-controlled, clinical trials (NCT00954447 and NCT01084005) of 24 and ≥52 weeks, respectively, were analysed. RESULTS: A total of 247 elderly individuals [mean ± standard deviation (s.d.) age 74 ± 4 years, glycated haemoglobin (HbA1c) 8.2 ± 0.8%] on basal insulin (mean ± s.d. baseline dose 36 ± 25 IU/day) were identified. Alongside placebo-adjusted change in HbA1c with linagliptin of -0.77% [95% confidence interval (CI) -0.95 to 0.59; p < 0.0001] after 24 weeks, the hazard ratios (HRs) of both overall and confirmed hypoglycaemia [blood glucose ≤3.9 mmol/l (70 mg/dl)], were significantly lower with linagliptin than with placebo: HR 0.61 (95% CI 0.39-0.97) versus 0.59 (95% CI 0.37-0.94), respectively (both p < 0.05). Moreover, significantly less confirmed hypoglycaemia was present in linagliptin-treated patients with renal impairment [HR 0.45 (95% CI 0.27-0.76)], moderate hyperglycaemia [HbA1c 7.5 to <9.0%; HR 0.51 (95% CI 0.27-0.99)], lower fasting plasma glucose levels [<152 mg/dl; HR 0.49 (95% CI 0.28-0.86)] and those treated with higher insulin doses [insulin ≥35.6 IU/day; HR 0.46 (95% CI 0.23-0.91); p < 0.05 for all]. Severe hypoglycaemia was rare and the incidence was lower with linagliptin (0.8%) versus placebo (2.5%): HR 0.21 (95% CI 0.02-2.30). CONCLUSIONS: Despite improvements in hyperglycaemia and no relevant on-trial insulin dose reductions, adding linagliptin to basal insulin appears to decrease hypoglycaemia risk. The biological basis of this phenomenon warrants further research but may involve counter-regulatory effects of incretin hormones.

Safety and efficacy of once-weekly dulaglutide versus sitagliptin after 2 years in metformin-treated patients with type 2 diabetes (AWARD-5): a randomized, phase III study.

AIMS: To compare the once-weekly glucagon-like peptide-1 (GLP-1) receptor dulaglutide with the dipeptidyl peptidase-4 (DPP-4) inhibitor sitagliptin after 104 weeks of treatment. METHODS: This AWARD-5 study was a multicentre, double-blind trial that randomized participants to dulaglutide (1.5 or 0.75 mg) or sitagliptin 100 mg for 104 weeks or placebo (reported separately) for 26 weeks. Change in glycated haemoglobin (HbA1c) concentration from baseline was the primary efficacy measure. A total of 1098 participants with HbA1c concentrations ≥7.0% (≥53.0 mmol/mol) and ≤9.5% (≤80.3 mmol/mol) were randomized, and 657 (59.8%) completed the study. We report results for dulaglutide and sitagliptin at the final endpoint. RESULTS: Changes in HbA1c at 104 weeks were (least squares mean ± standard error) -0.99 ± 0.06% (-10.82 ± 0.66 mmol/mol), -0.71 ± 0.07% (-7.76 ± 0.77 mmol/mol) and -0.32 ± 0.06% (-3.50 ± 0.66 mmol/mol) for dulaglutide 1.5 mg, dulaglutide 0.75 mg and sitagliptin, respectively (p < 0.001, both dulaglutide doses vs sitagliptin). Weight loss was greater with dulaglutide 1.5 mg (p < 0.001) and similar with 0.75 mg versus sitagliptin (2.88 ± 0.25, 2.39 ± 0.26 and 1.75 ± 0.25 kg, respectively). Gastrointestinal adverse events were more common with dulaglutide 1.5 and 0.75 mg versus sitagliptin (nausea 17 and 15% vs 7%, diarrhoea 16 and 12% vs 6%, vomiting 14 and 8% vs 4% respectively). Pancreatic, thyroid, cardiovascular and hypersensitivity safety were similar across groups. CONCLUSIONS: Dulaglutide doses provided superior glycaemic control and dulaglutide 1.5 mg resulted in greater weight reduction versus sitagliptin at 104 weeks, with acceptable safety.

LEADER 2: baseline calcitonin in 9340 people with type 2 diabetes enrolled in the Liraglutide Effect and Action in Diabetes: Evaluation of cardiovascular outcome Results (LEADER) trial: preliminary observations.

AIMS: To report preliminary data on baseline serum calcitonin concentrations and associated clinical characteristics in a global population with type 2 diabetes before liraglutide or placebo randomization. METHODS: The ongoing LEADER trial has enrolled 9340 people with type 2 diabetes and at high risk of cardiovascular disease at 410 centres worldwide. People with baseline serum calcitonin ≤ 50 ng/l were randomized to liraglutide once daily or placebo and will be followed for up to 5 years. Serum calcitonin was measured at baseline and will be measured annually thereafter. An independent committee of thyroid experts will oversee calcitonin monitoring throughout the trial and will review all calcitonin concentrations ≥ 20 ng/l. RESULTS: The mean age of participants was 64.3 ± 7.2 years, 64.3% were men, and mean the body mass index was 32.5 ± 6.3 kg/m(2). The median (interquartile range) baseline serum calcitonin values were 3.9 (1.0 to >7.6) ng/l in men and 1.0 (1.0 to >1) ng/l in women. Serum calcitonin was >10 ng/l in 14.6% of men and in 0.96% of women. In sex-specific multivariable linear analysis of covariance models, a reduced glomerular filtration rate (GFR) was associated with higher serum calcitonin concentrations that were statistically significant. A 20 ml/min/1.73 m(2) decrease in estimated GFR (eGFR) was associated with a 14% increase in serum calcitonin in women and an 11% increase in men. CONCLUSIONS: In the LEADER population, the prevalence of elevated serum calcitonin concentrations at baseline was high, and there was an inverse association between eGFR and serum calcitonin concentrations.

Durability of glycaemic efficacy over 2 years with dapagliflozin versus glipizide as add-on therapies in patients whose type 2 diabetes mellitus is inadequately controlled with metformin.

AIMS: To assess the long-term glycaemic durability, safety and tolerability of dapagliflozin versus glipizide as add-on therapies in patients with type 2 diabetes inadequately controlled by metformin alone. METHODS: This was a 52-week, randomised, double-blind study of dapagliflozin (n = 406) versus glipizide (n = 408), uptitrated over 18 weeks according to tolerability and glycaemic response to a maximum of 10 and 20 mg/day, respectively, as add-on therapies to metformin (≥ 1500 mg/day) with a 156-week double-blind extension period. Data over 104 weeks are reported here. RESULTS: In total, 53.1% of patients completed 104 weeks of treatment. After the greater initial decrease (0-18 weeks) in glycated haemoglobin (HbA1c) with glipizide, the 18-104-week HbA1c coefficient of failure (CoF) was lower with dapagliflozin (0.13%/year) than with glipizide (0.59%/year), resulting in significant dapagliflozin versus glipizide differences of -0.46%/year (95% CI -0.60,-0.33; p = 0.0001) for CoF and -0.18%(-2.0 mmol/mol) [95% CI -0.33(-3.6),-0.03(-0.3); p = 0.021] for 104-week HbA1c. Dapagliflozin produced sustained reductions in weight and systolic blood pressure, whereas glipizide increased weight and systolic blood pressure, giving 104-week dapagliflozin versus glipizide differences of -5.1 kg (95% CI: -5.7,-4.4) and -3.9 mmHg (95% CI: -6.1,-1.7), respectively. Over 104 weeks, the hypoglycaemia rate was 10-fold lower with dapagliflozin than with glipizide (4.2 vs. 45.8%), whereas patient proportions with events suggestive of genital infection and of urinary tract infection (UTI) were greater with dapagliflozin (14.8 and 13.5%, respectively) than with glipizide (2.9 and 9.1%, respectively). CONCLUSIONS: Over 2 years, compared with glipizide, dapagliflozin demonstrated greater glycaemic durability, sustained reductions in weight and systolic blood pressure and a low hypoglycaemia rate; however, genital infections and UTIs occurred more frequently.

Polypharmacy in people with Type 1 and Type 2 diabetes is justified by current guidelines--a comprehensive assessment of drug prescriptions in patients needing inpatient treatment for diabetes-associated problems.

AIMS: Our aim was to assess the number of medications prescribed to people with Type 1 or Type 2 diabetes mellitus and to compare these to recommendations by guidelines. PATIENTS AND METHODS: Data from 155 and 154 people with Type 1 and Type 2 diabetes, respectively, were analysed. Prescribed medications (glucose-lowering drugs, blood pressure medications, drugs to treat cardiovascular risk or diseases, etc.) were counted as compounds per day, tablets per day, injections per day, or other modes of administration. RESULTS: People with Type 2 diabetes were prescribed 8.4 ± 3.0 different drug compounds per day (maximum, 16), 8.6 ± 3.9 tablets per day (maximum, 22), 2.6 ± 1.6 injections per day (maximum, 7), in total 11.6 ± 4.5 doses of any medication per day (maximum, 27). The numbers for people with Type 1 diabetes were 5.5 ± 3.4 compounds per day (maximum, 15), 4.5 ± 4.3 tablets per day (maximum, 18), 3.9 ± 2.2 injections per day (maximum, 8), in total 8.5 ± 5.1 doses of any medication per day (maximum, 22). Over 97% of the prescriptions corresponded to recommendations by guidelines. CONCLUSIONS: The number of prescribed drugs is high in people with diabetes mellitus, and higher for those with Type 2 than with Type 1 diabetes. The compatibility of prescriptions with guideline recommendations suggests that even this high number of prescriptions will provide a clinical benefit. The current analysis could provide a basis for a realistic judgement of the burden imposed by polypharmacy in people with diabetes mellitus.

Do current incretin mimetics exploit the full therapeutic potential inherent in GLP-1 receptor stimulation?

Glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) are incretin-derived glucose-lowering agents that have been used for the treatment of type 2 diabetes since 2007. Agents such as exenatide (short-acting and once weekly preparations), liraglutide, taspoglutide, albiglutide and lixisenatide lower fasting glucose and HbA1c upon subcutaneous injection, leading to glycaemic control that is equivalent to, or better than, that observed with other oral glucose-lowering agents or bedtime insulin. However, varying proportions of patients report nausea and vomiting, adverse events that typically narrow the therapeutic dose range. Furthermore, GLP-1 RAs reduce fasting glucose to a clinically meaningful extent, but not into the normal range. In contrast, where GLP-1 is administered as a short-term intravenous infusion, a full normalisation of glucose concentrations (approximately 5 mmol/l) has been observed without any risk of gastrointestinal side effects. Subcutaneous infusions or injections of GLP-1 are much less effective. The present analysis relates the proportion of patients who report nausea following treatment with GLP-1 and GLP-1 RAs to the clinical effectiveness of the treatment (represented by the fasting glucose concentration achieved with treatment). The results suggest that GLP-1 RAs injected into the subcutaneous compartment do not exploit the full potential inherent in GLP-1 receptor activation. Reasons for this may include modifications of the peptide molecules in the subcutaneous environment or high local concentrations triggering side effects through GLP-1 receptors on autonomic nerves in subcutaneous adipose tissue. Elucidation of the mechanisms underlying differential responses to GLP-1/GLP-1 RAs administered intravenously vs subcutaneously may help to develop improved agents or modes of administration that are more effective and have fewer side effects.

The design of the liraglutide clinical trial programme.

Liraglutide is a once-daily human glucagon-like peptide-1 analogue used in the treatment of type 2 diabetes (T2D). It has been prospectively investigated in a series of multinational, randomised, controlled phase 3 trials (the Liraglutide Effect and Action in Diabetes programme), as well as in an additional direct head-to-head study with sitagliptin. These trials were designed to clarify the use and safety of liraglutide in clinical practice across the treatment continuum of T2D, and consequently involved a large number and diverse range of patients. These studies also included active comparisons against antidiabetic agents including metformin, rosiglitazone, glimepiride, insulin glargine, exenatide and sitagliptin, and therefore have helped to examine clinical differences and similarities between liraglutide and these commonly used agents.

Glycaemic rises after waking up in response to an alarm clock in type 1-diabetic patients analysed with continuous glucose monitoring (GlucoDay® S).

AIMS: Waking up in response to an alarm-clock may evoke a stress reaction that leads to rising glucose concentrations. METHOD: 30 type 1-diabetic patients participated in 3 overnight conditions: (a) with an alarm-clock set at 2 h intervals for glucose self monitoring, (b) with a nurse performing blood glucose determinations, and (c) with the patients left undisturbed. Continuous glucose monitoring (CGM) was performed with a GlucoDay® S device. RESULTS: After waking up in response to an alarm-clock, CGM-determined glucose concentrations rose by 18±6 mg/dl at 4 a.m. (p=0.0003), whereas negligible increments were seen with nurse assistance (e. g., 0±4 mg/dl at 4 a.m.). CONCLUSIONS: Waking up in response to an alarm-clock leads to an arousal reaction that causes significant elevations in glucose concentrations. Continuous glucose monitoring is a suitable method to detect such short-lived increments in glucose concentrations. But at the moment the CGMS is not able to substitute for inpatient glucose profiles.

Secretion of glucagon-like peptide-1 (GLP-1) in type 2 diabetes: what is up, what is down?

The incretin hormones gastric inhibitory polypeptide and especially glucagon-like peptide (GLP) have an important physiological function in augmenting postprandial insulin secretion. Since GLP-1 may play a role in the pathophysiology and treatment of type 2 diabetes, assessment of meal-related GLP-1 secretory responses in type 2 diabetic patients vs healthy individuals is of great interest. A common view states that GLP-1 secretion in patients with type 2 diabetes is deficient and that this applies to a lesser degree in individuals with impaired glucose tolerance. Such a deficiency is the rationale for replacing endogenous incretins with GLP-1 receptor agonists or re-normalising active GLP-1 concentrations with dipeptidyl peptidase-4 inhibitors. This review summarises the literature on this topic, including a meta-analysis of published studies on GLP-1 secretion in individuals with and without diabetes after oral glucose and mixed meals. Our analysis does not support the contention of a generalised defect in nutrient-related GLP-1 secretory responses in type 2 diabetes patients. Rather, factors are identified that may determine individual incretin secretory responses and explain some of the variations in published findings of group differences in GLP-1 responses to nutrient intake.

Weight loss with liraglutide, a once-daily human glucagon-like peptide-1 analogue for type 2 diabetes treatment as monotherapy or added to metformin, is primarily as a result of a reduction in fat tissue.

AIM: The effect on body composition of liraglutide, a once-daily human glucagon-like peptide-1 analogue, as monotherapy or added to metformin was examined in patients with type 2 diabetes (T2D). METHODS: These were randomized, double-blind, parallel-group trials of 26 [Liraglutide Effect and Action in Diabetes-2 (LEAD-2)] and 52 weeks (LEAD-3). Patients with T2D, aged 18-80 years, body mass index (BMI) < or =40 kg/m(2) (LEAD-2), < or =45 kg/m(2) (LEAD-3) and HbA1c 7.0-11.0% were included. Patients were randomized to liraglutide 1.8, 1.2 or 0.6 mg/day, placebo or glimepiride 4 mg/day, all combined with metformin 1.5-2 g/day in LEAD-2 and to liraglutide 1.8, 1.2 or glimepiride 8 mg/day in LEAD-3. LEAD-2/3: total lean body tissue, fat tissue and fat percentage were measured. LEAD-2: adipose tissue area and hepatic steatosis were assessed. RESULTS: LEAD-2: fat percentage with liraglutide 1.2 and 1.8 mg/metformin was significantly reduced vs. glimepiride/metformin (p < 0.05) but not vs. placebo. Visceral and subcutaneous adipose tissue areas were reduced from baseline in all liraglutide/metformin arms. Except with liraglutide 0.6 mg/metformin, reductions were significantly different vs. changes seen with glimepiride (p < 0.05) but not with placebo. Liver-to-spleen attenuation ratio increased with liraglutide 1.8 mg/metformin possibly indicating reduced hepatic steatosis. LEAD-3: reductions in fat mass and fat percentage with liraglutide monotherapy were significantly different vs. increases with glimepiride (p < 0.01). CONCLUSION: Liraglutide (monotherapy or added to metformin) significantly reduced fat mass and fat percentage vs. glimepiride in patients with T2D.