Efficacy and safety of liraglutide compared to sulphonylurea during Ramadan in patients with type 2 diabetes (LIRA-Ramadan): a randomized trial.

AIMS: Compare effects of liraglutide 1.8 mg and sulphonylurea, both combined with metformin, on glycaemic control in patients with type 2 diabetes (T2D) fasting during Ramadan. MATERIALS AND METHODS: In this up to 33-week, open-label, active-controlled, parallel-group trial, adults [glycated haemoglobin (HbA1c) 7%-10% (53-86 mmol/mol); body mass index ≥20 kg/m(2) ; intent to fast] were randomized (1:1) ≥10 weeks before Ramadan to either switch to once-daily liraglutide (final dose 1.8 mg) or continue pre-trial sulphonylurea at maximum tolerated dose, both with metformin. PRIMARY ENDPOINT: change in fructosamine, a validated marker of short-term glycaemic control, during Ramadan. RESULTS: Similar reductions in fructosamine levels were observed for both groups during Ramadan [liraglutide (-12.8 µmol/L); sulphonylurea (-16.4 µmol/L); estimated treatment difference (ETD) 3.51 µmol/L (95% CI: -5.26; 12.28); p = 0.43], despite lower fructosamine levels in the liraglutide group at start of Ramadan. Fewer documented symptomatic hypoglycaemic episodes were reported in liraglutide-treated (2%, three subjects) versus sulphonylurea-treated patients (11%, 18 subjects). No severe hypoglycaemic episodes were reported by either group. Body weight decreased more during Ramadan with liraglutide (ETD: -0.54 kg; 95% CI: -0.94;-0.14; p = 0.0091). The proportion of patients reporting adverse events was similar between groups. Liraglutide led to greater HbA1c reduction [ETD: -0.59% (-6.40 mmol/mol), 95% CI: -0.79; -0.38%; -8.63; -4.17 mmol/mol; p < 0.0001]. CONCLUSIONS: Despite lower fructosamine levels and body weight at the beginning of Ramadan, use of liraglutide showed similar glycaemic improvements, fewer hypoglycaemic episodes and greater body weight reduction compared with sulphonylurea. LIRA-Ramadan provides evidence for liraglutide being safe and efficacious for management of T2D during Ramadan fasting.

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.

A prospective, claims-based assessment of the risk of pancreatitis and pancreatic cancer with liraglutide compared to other antidiabetic drugs.

AIM: We evaluated the relationship between liraglutide and acute pancreatitis or pancreatic cancer in an ongoing post-marketing safety assessment programme. METHODS: Initiators of liraglutide, exenatide, metformin, pioglitazone or groups containing initiators of dipeptidyl peptidase-4 inhibitors or sulfonylureas were identified in a US commercial health insurance claims database (1 February 2010 to 31 March 2013) and followed for a median of 15 months. We estimated incidence rates (IR/100 000 person-years), rate ratio (RR) and 95% confidence intervals (CI) of new insurance claims with diagnoses of primary inpatient acute pancreatitis or pancreatic cancer from Poisson regression models. RESULTS: The IR for acute pancreatitis for liraglutide was 187.5 compared with 154.4 for all non-glucagon-like peptide-1 (GLP-1)-based therapies (adjusted RR 1.10; CI 0.81-1.49). The IR for pancreatic cancer was 19.9 for liraglutide compared with 33.0 for all non-GLP-1-based therapies (adjusted RR 0.65; 95% CI 0.26-1.60). CONCLUSION: We did not observe excess risk of either outcome associated with liraglutide relative to individual or pooled comparator drugs.

PACAP 1-38 as neurotransmitter in the porcine antrum.

UNLABELLED: The concentration of PACAP 1-38 in porcine antrum amounted to 15.4+/-7.9 and 20.3+/-8 pmol/g tissue in the mucosal and muscular layers. PACAP immunoreactive (IR) fibres innervated the muscular (co-localised with VIP) and submucosal/mucosal layers (some co-storing VIP and CGRP) including myenteric and submucosal plexus and blood vessels. Only myenteric nerve cell bodies contained PACAP-IR (co-storing VIP). In isolated perfused antrum, vagus nerve stimulation (8 Hz) and capsaicin (10(-5) M) increased PACAP 1-38 release. PACAP 1-38 (10(-9) M) increased substance P (SP), gastrin releasing peptide (GRP) and VIP release. PACAP 1-38 (10(-8) M) inhibited gastrin secretion and stimulated somatostatin secretion and motility dose-dependently. PACAP-induced motility was strongly inhibited by the antagonist PACAP 6-38 but also by atropine and substance P-antagonists (CP99994/SR48968) but PACAP 6-38 had no effect on vagus-induced secretion or motility. CONCLUSION: PACAP 1-38 may be involved in antral motility and secretion by interacting with cholinergic, SP-ergic, GRP-ergic and/or VIP-ergic neurones, and may also be involved in afferent reflex pathways.

PACAP-(1-38) as neurotransmitter in the porcine adrenal glands.

The concentration of pituitary adenylyl cyclase-activating polypeptide [PACAP-(1-38)] in porcine adrenal glands amounted to 14 +/- 3 pmol/g tissue. PACAP immunoreactive (PACAP-IR) fibers innervated adrenal chromaffin cells (often co-localized with choline acetyltransferase). Subcapsular fibers traversed the cortex-innervating endocrine cells and blood vessels [some co-storing mainly calcitonin gene-related peptide but also vasoactive intestinal polypeptide (VIP)]. PACAP-IR fibers were demonstrated in the splanchnic nerves, whereas IR adrenal nerve cell bodies were absent. In isolated, vascularly perfused adrenal gland, splanchnic nerve stimulation (16 Hz) and capsaicin (10(-5) M) increased PACAP-(1-38) release (1.6-fold and 6-fold respectively, P = 0.02). PACAP-(1-38) dose-dependently stimulated cortisol (2 x 10(-10) M; 24-fold increase, P = 0.02) and chromogranin A fragment (2 x 10(-9) M; 15-fold increase, P = 0.05) secretion. Both were strongly inhibited by the PAC(1)/VPAC(2) receptor antagonist PACAP-(6-38) (10(-7) M). PACAP-(6-38) also inhibited splanchnic nerve (10 Hz)-induced cortisol secretion but lacked any effect on splanchnic nerve-induced pancreastatin secretion. PACAP-(1-38) (2 x 10(-10) M) decreased vascular resistance from 5.5 +/- 0.6 to 4.6 +/- 0.4 mmHg. min. ml(-1). PACAP-(6-38) had no effect on this response. We conclude that PACAP-(1-38) may play a role in splanchnic nerve-induced adrenal secretion and in afferent reflex pathways.

Tachykinins in the porcine pancreas: potent exocrine and endocrine effects via NK-1 receptors.

The localization, release, and effects of substance P and neurokinin A were studied in the porcine pancreas and the localization of substance P immunoreactive nerve fibers was examined by immunohistochemistry. The effects of electrical vagus stimulation and capsaicin infusion on tachykinin release and the effects of substance P and neurokinin A infusion on insulin, glucagon, somatostatin, and exocrine secretion were studied using the isolated perfused porcine pancreas with intact vagal innervation. NK-1 and NK-2 receptor antagonists were used to investigate receptor involvement. Substance P immunoreactive nerve fibers were localized to islets of Langerhans, acini, ducts, and blood vessels. Vagus stimulation had no effect on substance P and neurokinin A release, whereas capsaicin infusion stimulated release of both. Substance P and neurokinin A infusion increased release of insulin, glucagon, and exocrine secretion, whereas somatostatin secretion was unaffected. The effect of substance P on insulin, glucagon, and exocrine secretion was blocked by the NK-1 receptor antagonist. The effect of electrical stimulation of vagus nerves on insulin and exocrine secretion was not influenced by tachykinin receptor antagonists. We conclude that tachykinins stimulate both endocrine and exocrine pancreatic functions through NK-1 receptors. Tachykinins are not involved in vagal regulation of pancreatic secretion in pigs but could constitute part of an alternative stimulatory system.

Pituitary adenylate cyclase-activating polypeptide stimulates insulin and glucagon secretion in humans.

Pituitary adenylate cyclase-activating polypeptide (PACAP) has been localized to pancreatic nerves and demonstrated to stimulate insulin and glucagon secretion in experimental animals. This study examined the occurrence and possible function of PACAP in the human pancreas. The content of PACAP27 was 0.44 +/- 0.04 pmol/g tissue, and that of PACAP38 was 29.6 +/- 6.4 pmol/g tissue in extracted human pancreas (n = 4). Furthermore, in a homogeneous group of seven healthy postmenopausal women, all aged 57 yr, iv infusion of synthetic human PACAP27 (3 pmol/kg.min for 75 min) increased basal levels of insulin, C peptide, and glucagon without significantly influencing basal glucose after 14 min. At 15 min, glucose was administered rapidly (0.3 g/kg, iv). The peak insulin after bolus glucose was 797 +/- 232 pmol/L during PACAP27 infusion vs. 559 +/- 164 pmol/L during saline infusion (P = 0.018). Also, the peak in C peptide after glucose was potentiated by PACAP27 (P = 0.018). In contrast, hepatic extraction, calculated as the C peptide/insulin molar ratio, was not significantly affected by PACAP27, and neither the glucose elimination rate nor reduction of serum insulin after the glucose-induced peak was changed by PACAP27. We conclude that PACAP occurs in human pancreas and stimulates insulin and glucagon secretion in humans. This suggests that PACAP is involved in the regulation of islet function in humans.

PACAP-(1-38) as neurotransmitter in pig pancreas: receptor activation revealed by the antagonist PACAP-(6-38).

The pituitary adenylyl cyclase-activating polypeptide PACAP-(1-38) has potent pancreatic secretory effects. We studied its immunohistochemical localization, release, and contribution to secretion induced by electrical vagus stimulation using isolated perfused porcine pancreas and the PACAP receptor antagonist PACAP-(6-38) (10(-7) M). PACAP was found in nerve fibers throughout the pancreas but, in particular, encircling ganglionic vasoactive intestinal polypeptide (VIP)-positive nerve cell bodies and, mostly, colocalized with VIP. Vagus stimulation caused its release. PACAP-(1-38)(4 x 10(-9) M) stimulated exocrine and endocrine secretion and released VIP. PACAP-(6-38) decreased PACAP-induced flow of juice to 59 +/- 7.8% and insulin secretion and VIP release to 12 +/- 6.8 and 57 +/- 13%, respectively. Glucagon secretion was unaffected. PACAP-(6-38) reduced vagus-stimulated flow rate to 63 +/- 7.6%, insulin and glucagon responses to 31.8 +/- 13 and 6 +/- 4%, respectively, and VIP release to 23 +/- 8.4% and reduced VIP-induced (2 x 10(-9) M) juice and insulin (but not glucagon) outputs to 8.3 +/- 4.2 and 67 +/- 14%, respectively. In conclusion, 1) pancreatic PACAP fibers seem to activate intrapancreatic VIPergic neurons, 2) PACAP-(6-38) antagonism documents the role of VIP/PACAP for neural regulation but cannot distinguish their relative importance, and 3) a PACAP receptor with low affinity for PACAP-(6-38), associated with glucagon cells, may exist.

Oxidative DNA damage after transplantation of the liver and small intestine in pigs.

Oxidative damage is thought to play an important role in ischemia/reperfusion injury, including the outcome of transplantation of the liver and intestine. We have investigated oxidative DNA damage after combined transplantation of the liver and small intestine in 5 pigs. DNA damage was estimated from the urinary excretion of the repair product 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG). In the first 1-3 hr after reperfusion of the grafts, 8-oxodG excretion was increased 2.9-fold (1.7-4.1; 95% confidence intervals; P < 0.05). A control experiment included sham surgery with clamping of the suprarenal inferior caval vein in 2 pigs during steady state infusion of 8-oxodG. While the caval vein was clamped, the urinary excretion of 8-oxodG was almost blocked, whereas after removal of the clamp, the excretion returned to and did not exceed the preclamp levels. In a separate experiment with 2 pigs, the elimination of injected 8-oxodG was shown to adhere to first-order kinetics with a clearance and a terminal elimination half-life of approximately 4 ml min-1 kg-1 and 2 1/2 hr, respectively. The injected dose was completely excreted into the urine within 4 hr. It is concluded that substantial oxidative damage to DNA results from reperfusion of transplanted small intestine and liver in pigs, as estimated from the readily excreted repair product 8-oxodG.

Histochemical, pharmacological, biochemical and chromatographic evidence that pituitary adenylyl cyclase activating peptide is involved in inhibitory neurotransmission in the taenia of the guinea-pig caecum.

The possibility that pituitary adenylyl cyclase-activating peptide (PACAP) is an inhibitory neurotransmitter has been investigated in the taenia of the guinea-pig caecum. The action of PACAP on muscle contractility and its ability to alter levels of adenosine-3':5'-cyclic monophosphate (cyclic AMP) and guanosine-3':5'-cyclic monophosphate (cyclic GMP) were investigated. PACAP-1-27 was an effective agonist, giving relaxations comparable in magnitude to isoproterenol; its EC50 was 3.4 x 10(-7) M. PACAP (10(-6) M) caused an almost two-fold increase in cyclic AMP levels; but the level of cyclic GMP was not affected. The relaxation caused by PACAP was slow in onset, with a latency of 5.8 +/- 0.8 s and reached a maximum at 9.1 +/- 1.1 s after onset. The relaxation was significantly reduced by apamin (10(-6) M) and suramin (10(-4) M) but was not reduced by tetrodotoxin (10(-7) M). Relaxation of the taenia coli caused by electrical stimulation of the inhibitory nerves was greatly reduced by apamin but only slightly reduced by suramin. PACAP-like immunoreactivity (-IR) was localised immunohistochemically in varicose nerve fibres within the taenia coli and in the underlying myenteric plexus and circular muscle. Approx. 50% of vasoactive intestinal peptide (VIP)-IR nerve fibres in the taenia also had immunoreactivity for PACAP; conversely, almost all PACAP-IR fibres were immunoreactive for VIP. PACAP-IR and substance P (SP)-IR were generally in separate fibres; only about 5% of SP-IR fibres were PACAP-IR. Radioimmunoassay revealed tissue concentrations of PACAP-1-27 and PACAP-1-38 of 1.0 +/- 0.1 and 2.1 +/- 0.3 (SEM) pmol/g wet weight of tissue, respectively. Material with PACAP-1-27 immunoreactivity co-eluted with authentic PACAP-1-27 on gel filtration chromatography, and PACAP-1-38 immunoreactivity also co-eluted with the authentic peptide. This study provides structural, chemical and pharmacological evidence that PACAP could be involved in inhibitory neurotransmission to the taenia coli of the guinea-pig caecum.