Association of GLP-1 secretion with parameters of glycemic control in women after gestational diabetes mellitus.

INTRODUCTION: Women with a history of gestational diabetes mellitus (GDM) are at high risk of developing type 2 diabetes, while the exact mechanisms underlying its pathophysiology are still unclear. We investigated the association of glucagon-like peptide-1 (GLP-1) response to oral glucose with parameters of glycemic control in women with previous GDM in the prospective PPSDiab (Prediction, Prevention, and Subclassification of Type 2 Diabetes) study. RESEARCH DESIGN AND METHODS: Glucose metabolism parameters and GLP-1 secretion were analyzed during oral glucose tolerance test (OGTT) in women with previous GDM (n=129) and women with a history of normal glucose tolerance (n=67) during pregnancy (controls). First- and second-phase insulin and GLP-1 secretion in relation to plasma glucose (PG) levels were assessed, and development of pre-diabetes was analyzed after 5-year follow-up among women with previous GDM and a normal glycemic state at baseline (n=58). RESULTS: The area under the curve (AUC during the OGTT 0-120 min) of PG and insulin but not GLP-1 differed significantly between post-GDM women and controls. However, women with previous GDM had a significantly decreased GLP-1 response in relation to PG and plasma insulin during the second phase of the OGTT. After a follow-up of 5 years, 19.0% post-GDM women with a normal glycemic state at the baseline visit developed abnormal glucose metabolism. The total, first- and second-phase AUC GLP-1/PG and GLP-1/insulin ratios were not associated with development of abnormal glucose tolerance. CONCLUSIONS: Women with previous GDM showed a reduced GLP-1 response in relation to PG and insulin concentrations indicating early abnormalities in glucose metabolism. However, the altered GLP-1 response to oral glucose did not predict progression to pre-diabetes and type 2 diabetes in the first 5 years after GDM.

Survival with Good Neurological Outcome despite Prolonged Cardiopulmonary Resuscitation and Extreme Acidosis after Out-of-Hospital Cardiac Arrest Due to Acute Myocardial Infarction: A Case Report and Review of the Literature.

We report the case of a 49-year-old male who suffered from a myocardial infarction with subsequent cardiac arrest. The emergency medical team began cardiopulmonary resuscitation, including defibrillation of ventricular fibrillation. Although a return of spontaneous circulation was achieved after approximately 30 min of continued efforts, the patient went back into cardiac arrest on the way to the hospital and resuscitation had to be resumed. On admission, the patient was severely acidotic with a pH of 6.67, lactatemia of 19 mmol/L, and pronounced hypercapnia (pCO2 127 mmHg). Despite the poor prognosis, all possible efforts including coronary intervention and therapeutic hypothermia were carried out and the patient made a quick recovery with discharge from the intensive care unit on day 5. Survival of extreme acidosis, such as in this case, is rare. This is the first report of survival with good neurologic outcome in a patient with myocardial infarction, cardiac arrest, and pH of under 6.7 on admission at the clinic.

Effect of PCSK9 inhibition with evolocumab on lipoprotein subfractions in familial dysbetalipoproteinemia (type III hyperlipidemia).

BACKGROUND AND AIMS: Familial dysbetalipoproteinemia (FDBL) is a rare inborn lipid disorder characterized by the formation of abnormal triglyceride- and cholesterol-rich lipoproteins (remnant particles). Patients with FDBL have a high risk for atherosclerotic disease. The effect of PCSK9 inhibition on lipoproteins and its subfractions has not been evaluated in FDBL. METHODS: Three patients (65±7 years, 23±3 kg/m2, 2 females) with FDBL (diagnosed by isoelectrofocusing) and atherosclerosis (coronary and/or cerebro-vascular and/or peripheral arterial disease) resistant or intolerant to statin and fibrate therapy received evolocumab (140mg every 14 days). In addition to a fasting lipid profile (preparative ultracentrifugation), apoB and cholesterol concentrations were determined in 15 lipoprotein-subfractions (density gradient ultracentrifugation; d 1.006-1.21g/ml) before and after 12 weeks of evolocumab treatment. Patients with LDL-hypercholesterolemia (n = 8, 56±8 years, 31±7 kg/m2) and mixed hyperlipidemia (n = 5, 68±12 years, 30±1 kg/m2) also receiving evolocumab for 12 weeks were used for comparison. RESULTS: All patients tolerated PCSK9 inhibition well. PCSK9 inhibitors reduced cholesterol (29-37%), non-HDL-cholesterol (36-50%) and apoB (40-52%) in all patient groups including FDBL. In FDBL, PCSK9 inhibition reduced VLDL-cholesterol and the concentration of apoB containing lipoproteins throughout the whole density spectrum (VLDL, IDL, remnants, LDL). Lipoprotein(a) was decreased in all patient groups to a similar extent. CONCLUSIONS: This indicates that the dominant fraction of apoB-containing lipoproteins is reduced with PCSK9 inhibition, i.e. LDL in hypercholesterolemia and mixed hyperlipidemia, and cholesterol-rich VLDL, remnants and LDL in FDBL. PCSK9 inhibition may be a treatment option in patients with FDBL resistant or intolerant to statin and/or fibrate therapy.

Btk Inhibitors as First Oral Atherothrombosis-Selective Antiplatelet Drugs?

Bruton's tyrosine kinase (Btk) is essential for B cell differentiation and proliferation, but also platelets express Btk. Patients with X-linked agammaglobulinemia due to hereditary Btk deficiency do not show bleeding, but a mild bleeding tendency is observed in high dose therapy of B-cell malignancies with ibrutinib and novel second-generation irreversible Btk inhibitors (acalabrutinib and ONO/GS-4059). This review discusses recent studies that may explain this apparent paradox and gives mechanistic insights that suggest a unique potential of low dose irreversible Btk inhibitors as atherothrombosis-focused antiplatelet drugs.

Optimizing Platelet GPVI Inhibition versus Haemostatic Impairment by the Btk Inhibitors Ibrutinib, Acalabrutinib, ONO/GS-4059, BGB-3111 and Evobrutinib.

Ibrutinib and acalabrutinib are approved for B cell malignancies and novel Bruton's tyrosine kinase (Btk) inhibitors undergo clinical testing also in B cell-driven autoimmune disorders. Btk in platelets mediates platelet activation via glycoprotein (GP) VI, which is crucial for atherosclerotic plaque-induced platelet thrombus formation. This can be selectively inhibited by Btk inhibitors. Since patients on second-generation Btk inhibitors apparently show less bleeding than patients on ibrutinib, we compared the effects of ibrutinib and four novel irreversible Btk inhibitors on GPVI-dependent platelet aggregation in blood and in vitro bleeding time. Low concentrations of collagen which induced the same low degree of GPVI-mediated platelet aggregation as atherosclerotic plaque material were applied. IC50 values for collagen (0.2-0.5 µg/mL)-induced platelet aggregation after 15-minute pre-incubation were: ibrutinib 0.12 µM, BGB-3111 0.51 µM, acalabrutinib 1.21 µM, ONO/GS-4059 1.20 µM and evobrutinib 5.84 µM. Peak venous plasma concentrations of ibrutinib (0.5 µM), acalabrutinib (2 µM) and ONO/GS-4059 (2 µM) measured after anti-proliferative dosage inhibited collagen-induced platelet aggregation, but did not increase PFA-200 closure time on collagen/epinephrine. Closure times were moderately increased by 2- to 2.5-fold higher concentrations of these inhibitors, but not by BGB-3111 (1 µM) and evobrutinib (10 µM). Prolonging platelet drug exposure to 60 minutes lowered IC50 values of any Btk inhibitor for GPVI-mediated aggregation by several fold, and 5- to 10-fold below anti-proliferative therapeutic drug plasma levels. In conclusion, low blood concentrations of ibrutinib and the novel Btk inhibitors suffice for GPVI selective platelet inhibition relevant for atherothrombosis but do not impair primary haemostasis.

Oral Bruton tyrosine kinase inhibitors selectively block atherosclerotic plaque-triggered thrombus formation in humans.

Interaction of von Willebrand factor (VWF) with platelet glycoprotein Ib (GPIb) and interaction of collagen with GPVI are essential for thrombus formation on ruptured or eroded atherosclerotic plaques (atherothrombosis). GPIb and GPVI signal through Bruton tyrosine kinase (Btk), which can be blocked irreversibly by oral application of ibrutinib, an established therapy for chronic lymphocytic leukemia (CLL) with long-term safety. We found that ibrutinib and the novel Btk inhibitors acalabrutinib and ONO/GS-4059 block GPVI-dependent static platelet aggregation in blood exposed to human plaque homogenate and collagen but not to ADP or arachidonic acid. Moreover, Btk inhibitors prevented platelet thrombus formation on human atherosclerotic plaque homogenate and plaque tissue sections from arterially flowing blood, whereas integrin α2ß1 and VWF-dependent platelet adhesion to collagen, which is important for physiologic hemostasis, was not affected. This plaque-selective platelet inhibition was also observed in CLL patients taking 450 mg of ibrutinib and in volunteers after much lower and intermittent dosing of the drug. We conclude that Btk inhibitors, by targeting GPIb and GPVI signal transduction, suppress platelet thrombus accretion from flowing blood on atherosclerotic plaque but spare hemostatic platelet function. Btk inhibitors hold promise as the first culprit lesion-focused oral antiplatelet drugs and are effective at low doses.