34 research outputs found
Comparative pharmacodynamic and pharmacokinetic characteristics of subcutaneous insulin glulisine and insulin aspart prior to a standard meal in obese subjects with type 2 diabetes
Aims: A multinational, randomized, double-blind, two-way crossover trial to compare the pharmacokinetic and pharmacodynamic properties of bolus, subcutaneously administered insulin glulisine (glulisine) and insulin aspart (aspart) in insulin-naÏve, obese subjects with type 2 diabetes
Increased interleukin-6 levels are associated with atrioventricular conduction delay in severe COVID-19 patients
BackgroundSeverely ill patients with coronavirus disease 2019 (COVID-19) show an increased risk of new-onset atrioventricular blocks (AVBs), associated with high rates of short-term mortality. Recent data suggest that the uncontrolled inflammatory activation observed in these patients, specifically interleukin (IL)-6 elevation, may play an important pathogenic role by directly affecting cardiac electrophysiology. The aim of our study was to assess the acute impact of IL-6 changes on electrocardiographic indices of atrioventricular conduction in severe COVID-19. MethodsWe investigated (1) the behavior of PR-interval and PR-segment in patients with severe COVID-19 during active phase and recovery, and (2) their association with circulating IL-6 levels over time. ResultsDuring active disease, COVID-19 patients showed a significant increase of PR-interval and PR-segment. Such atrioventricular delay was transient as these parameters rapidly normalized during recovery. PR-indices significantly correlated with circulating IL-6 levels over time. All these changes and correlations persisted also in the absence of laboratory signs of cardiac strain/injury or concomitant treatment with PR-prolonging drugs, repurposed or not. ConclusionsOur study provides evidence that in patients with severe COVID-19 and high-grade systemic inflammation, IL-6 elevation is associated with a significant delay of atrioventricular conduction, independent of concomitant confounding factors. While transient, such alterations may enhance the risk of severe AVB and associated short-term mortality. Our data provide further support to current anti-inflammatory strategies for severe COVID-19, including IL-6 antagonists
Hyperglycemia-Induced Platelet Activation in Type 2 Diabetes Is Resistant to Aspirin but Not to a Nitric Oxide–Donating Agent
OBJECTIVE: Acute, short-term hyperglycemia enhances high shear stress-induced platelet activation in type 2 diabetes. Several observations suggest that platelets in type 2 diabetes are resistant to inhibition by aspirin. Our aim was to assess comparatively the effect of aspirin, a nitric oxide-donating agent (NCX 4016), their combination, or placebo on platelet activation induced by acute hyperglycemia in type 2 diabetes.
RESEARCH DESIGN AND METHODS: In a double-blind, placebo-controlled, randomized trial, 40 type 2 diabetic patients were allocated to 100 mg aspirin once daily, 800 mg NCX 4016 b.i.d., both of them, or placebo for 15 days. On day 15, 1 h after the morning dose, a 4-h hyperglycemic clamp (plasma glucose 13.9 mmol/l) was performed, and blood samples were collected before and immediately after it for platelet activation and cyclooxygenase-1 (COX-1) inhibition studies. RESULTS Acute hyperglycemia enhanced shear stress-induced platelet activation in placebo-treated patients (basal closure time 63 +/- 7.1 s, after hyperglycemia 49.5 +/- 1.4 s, -13.5 +/- 6.3 s, P < 0.048). Pretreatment with aspirin, despite full inhibition of platelet COX-1, did not prevent it (-12.7 +/- 6.9 s, NS vs. placebo). On the contrary, pretreatment with the NO donor NCX 4016, alone or in combination with aspirin, suppressed platelet activation induced by acute hyperglycemia (NCX 4016 +10.5 +/- 8.3 s; NCX 4016 plus aspirin: +12.0 +/- 10.7 s, P < 0.05 vs. placebo for both). Other parameters of shear stress-dependent platelet activation were also more inhibited by NCX 4016 than by aspirin, despite lesser inhibition of COX-1.
CONCLUSIONS: Acute hyperglycemia-induced enhancement of platelet activation is resistant to aspirin; a NO-donating agent suppresses it. Therapeutic approaches aiming at a wider platelet inhibitory action than that exerted by aspirin may prove useful in patients with type 2 diabetes
Advanced Atrioventricular Block in Athletes: Prevalence and Role of Anti-Ro/Sjögren Syndrome-Related Antigen A Antibodies
BACKGROUND: Advanced atrioventricular block (AVB), that is, higher than second-degree Mobitz-1, is an abnormal finding in athletes. Despite intensive investigation, in several cases the pathogenesis remains unknown, but frequently pacemaker implantation is still indicated. Increasing evidence points to circulating anti-Ro/Sjögren syndrome-related antigen A (SSA) antibodies cross-reacting with L-type calcium channel and inhibiting the related current as an epidemiologically relevant and potentially reversible cause of isolated AVB in adults. The aim of the study was to determine the prevalence of anti-Ro/SSA-associated advanced AVBs in a large sample of young athletes. METHODS AND RESULTS: A total of 2536 consecutive athletes aged <40 years without a history of cardiac diseases/interventions were enrolled in a cross-sectional study. Resting and exercise electrocardiography was performed, and those presenting any AVB were further evaluated by 24-hour Holter ECG. Athletes with second-degree AVBs and their mothers underwent anti-Ro/SSA testing. Moreover, purified immunoglobulin G from subjects with anti-Ro/SSA-positive and anti-Ro/SSA-negative advanced AVB were tested on L-type calcium current and L-type-calcium channel expression using tSA201 cells. The global prevalence of advanced AVB in the overall sample was ≈0.1%, but the risk considerably increased (2%) when intensely trained postpubertal male subjects were selectively considered. While none of the athletes with advanced AVB showed heart abnormalities, in 100% of cases anti-Ro/SSA antibodies were detected. Ex vivo experiments showed that immunoglobulin G from anti-Ro/SSA-positive but not -negative subjects with advanced AVB acutely inhibit L-type calcium current and chronically downregulate L-type-calcium channel expression. CONCLUSIONS: Our study provides evidence that advanced AVB occurs in young athletes, in most cases associated with anti-Ro/SSA antibodies blocking L-type calcium channels. These findings may open new avenues for immunomodulating therapies to reduce the risk of life-threatening events in athletes, avoiding or delaying pacemaker implantation
Blood Cell Mitochondrial DNA Content and Premature Ovarian Aging.
Primary ovarian insufficiency (POI) is a critical fertility defect characterized by an anticipated and silent impairment of the follicular reserve, but its pathogenesis is largely unexplained. The frequent maternal inheritance of POI together with a remarkable dependence of ovarian folliculogenesis upon mitochondrial biogenesis and bioenergetics suggested the possible involvement of a generalized mitochondrial defect. Here, we verified the existence of a significant correlation between blood and ovarian mitochondrial DNA (mtDNA) content in a group of women undergoing ovarian hyperstimulation (OH), and then aimed to verify whether mtDNA content was significantly altered in the blood cells of POI women. We recruited 101 women with an impaired ovarian reserve: 59 women with premature ovarian failure (POF) and 42 poor responders (PR) to OH. A Taqman copy number assay revealed a significant mtDNA depletion (P<0.001) in both POF and PR women in comparison with 43 women of similar age and intact ovarian reserve, or 53 very old women with a previous physiological menopause. No pathogenic variations in the mitochondrial DNA polymerase γ (POLG) gene were detected in 57 POF or PR women with low blood mtDNA content. In conclusion, blood cell mtDNA depletion is a frequent finding among women with premature ovarian aging, suggesting that a still undetermined but generalized mitochondrial defect may frequently predispose to POI which could then be considered a form of anticipated aging in which the ovarian defect may represent the first manifestation. The determination of mtDNA content in blood may become an useful tool for the POI risk prediction
Primary ovarian insufficiency: autoimmune causes.
To review the pathogenesis of premature ovarian insufficiency due to steroid cell autoimmunity (SCA-POI).Autoimmune oophoritis is characterized by a selective mononuclear cell infiltration into the theca layer of large, antral follicles, with earlier stage follicles consistently free of lymphocytic infiltration. SCA-POI is caused by the selective autoimmune destruction of theca cells with preservation of granulosa cells that produce low amounts of estradiol because of lack of substrates. Typically, serum concentrations of inhibins are increased in women with SCA-POI, as compared to both healthy fertile women and women with other forms of ovarian insufficiency. Normal serum antim\ufcllerian hormone (AMH) concentrations were detected in two-thirds of women with recently diagnosed SCA-POI, which demonstrates that this form of ovarian insufficiency is associated with a preserved pool of functioning follicles.The combined measurement of autoantibodies and markers of ovarian reserve (as inhibin B and AMH) may permit to identify women with POI due to steroid cell autoimmunity with a preserved proportion of primordial and primary follicles. In the future the development of techniques of in-vitro folliculogenesis may permit new treatment strategies for women with SCA-POI-related infertility
High serum inhibin concentration discriminates autoimmune oophoritis from other forms of primary ovarian insufficiency
Context: Primary ovarian insufficiency (POI) is defined by hypergonadotropic amenorrhea occurring
before the age of 40 yr. In 4–5% of women with POI, an ovarian autoimmune process can be
demonstrated.
Design: We have determined the serum concentrations of total inhibin and inhibin B by sensitive
ELISAs in 22womenwith autoimmune POI (aPOI), 71womenwith non-autoimmune idiopathic POI
(iPOI), 77 postmenopausal women, and 90 healthy, fertile women (HW). Diagnosis of aPOI was
made according to the presence of steroid cell autoantibodies and/or 17-hydroxylase autoantibodies
and/or cytochrome P450 side-chain cleavage autoantibodies. All aPOI patients were also
positive for adrenal autoantibodies.
Results: Total inhibin levels were significantly higher inwomenwith aPOI (median, 281 pg/ml) than
in women with iPOI (median, 74 pg/ml) or HW (median, 133.5 pg/ml) (P 0.001). Levels of inhibin
B were also significantly higher in women with aPOI (median, 109 pg/ml) than in women with iPOI
(median, 18 pg/ml) (P 0.001) orHW(median, 39 pg/ml) (P 0.05). Serum concentrations of total
inhibin and inhibin B were significantly higher inwomenwith POI than in postmenopausalwomen
(P 0.001), irrespective of the presence/absence of autoantibodies. At receiver-operating characteristic
analysis, cutoff values of 133 pg/ml for total inhibin and 60.5 pg/ml for inhibin B ensured
86.4% sensitivity and 81–84.5% specificity for aPOI vs. iPOI.
Conclusions: We conclude that a variable degree of ovarian function is preserved in women with
POI and that aPOI is characterized by increased inhibin production resulting from a selective theca
cell destruction, with initial preservation of granulosa cells