Rate of post-bariatric hypoglycemia using continuous glucose monitoring: A meta-analysis of literature studies

AIMS

Hypoglycemia is a serious complication of bariatric surgery. The aim of the present meta-analysis was to evaluate the rate and the timing of post-bariatric hypoglycemia (PBH) with different bariatric procedures using reliable data from continuous glucose monitoring (CGM).

DATA SYNTHESIS

Studies were systematically searched in the Web of Science, Scopus and PubMed databases according to Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. The prevalence of PBH was expressed as weighted mean prevalence (WMP) with pertinent 95% confidence intervals (95%CI). A total of 8 studies (16 datasets) enrolling 280 bariatric subjects were identified. The total WMP of PBH was 54.3% (95%CI: 44.5%-63.8%) while the WMP of nocturnal PBH was 16.4% (95%CI: 7.0%-34%). We found a comparable rate of PBH after Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) (OR 1.62, 95%CI: 0.71-3.7; P = 0.248); likewise, the percent time spent in hypoglycemia was similar with the two procedures (mean difference 5.3%, 95%CI: -1.4%-12.0%; P = 0.122); however, RYGB was characterized by a higher glycemic variability than SG. Regression models showed that the time elapsed from surgical intervention was positively associated with a higher rate of both total PBH (Z-value: 3.32, P < 0.001) and nocturnal PBH (Z-value: 2.15, P = 0.013).

CONCLUSIONS

PBH, both post-prandial and nocturnal, is more prevalent than currently believed. The rate of PBH increases at increasing time from surgery and is comparable after RYGB and SG with a higher glucose variability after RYGB.

Plasma phospholipid dysregulation in patients with cystathionine-β synthase deficiency

BACKGROUND & AIMS

Patients with cystathionine β-synthase deficiency (CBSD) exhibit high circulating levels of homocysteine and enhanced lipid peroxidation. We have characterized the plasma lipidome in CBSD patients and related lipid abnormalities with reactions underlying enhanced homocysteine levels.

METHODS AND RESULTS

Using an ultra-high-performance liquid chromatography-electrospray ionization-quadrupole-time of flight-mass spectrometry method, plasma lipids were determined with an untargeted lipidomics approach in 11 CBSD patients and 11 matched healthy subjects (CTRL). Compared to CTRL, CBSD patients had a higher medium and long-chain polyunsaturated fatty acids (PUFA) content in phosphatidylethanolamine (PE) and lysophosphatidylethanolamine (LPE) species (p < 0.02), and depletion of phosphatidylcholine (PC; p = 0.02) and of lysophosphatidylcholine (LPC; p = 0.003) species containing docosahexaenoic acid (DHA), suggesting impaired phosphatidylethanolamine-N-methyltransferase (PEMT) activity. PEMT converts PE into PC using methyl group by S-adenosylmethionine (SAM) thus converted in S-adenosylhomocysteine (SAH). Whole blood SAM and SAH concentrations by liquid chromatography tandem mass spectrometry were 1.4-fold (p = 0.015) and 5.3-fold (p = 0.003) higher in CBSD patients than in CTRL. A positive correlation between SAM/SAH and PC/PE ratios (r = 0.520; p = 0.019) was found.

CONCLUSIONS

A novel biochemical abnormality in CBSD patients consisting in depletion of PC and LPC species containing DHA and accumulation of PUFA in PE and LPE species is revealed by this lipidomic approach. Changes in plasma SAM and SAH concentrations are associated with such phospholipid dysregulation. Given the key role of DHA in thrombosis prevention, depletion of PC species containing DHA in CBSD patients provides a new direction to understand the poor cardiovascular outcome of patients with homocystinuria.

Role of clinical and laboratory parameters for treatment choice in patients with inherited FVII deficiency undergoing surgical procedures: evidence from the STER registry

Perioperative bleeding is a major concern in patients with factor VII (FVII) deficiency. Evaluating data of 95 FVII-deficient patients undergoing 110 surgical procedures (61 major, 49 minor), we assessed the impact of type of surgery, bleeding phenotype and FVII coagulant activity (FVII:C) levels on perioperative replacement therapy (RT). Compared to those with higher FVII:C levels, patients with <3% FVII:C received a higher number of RT doses (8 vs. 2, P = 0·003) for a longer RT duration (3 days vs. 1 day, P = 0·001), with no difference in RT dose. Similarly, patients with a history of major bleeds received a higher number of RT doses (8·5 vs. 2-3, P = 0·013) for a longer RT duration (2 days vs. 1 day, P = 0·005) as compared to those with a history of minor bleeds or to asymptomatic patients. No difference in RT was found among major and minor surgical procedures. Overall, multivariate analysis showed that history of major bleeding was the only independent predictor of number of RT doses (β = 0·352, P = 0·001) and RT duration (β = 0·405, P = 0·018). Overall, a ≈20 μg/kg perioperative RT was efficacious in 95·5% of cases. The infusion should be repeated ≈8 times in high-risk subsets (i.e. patients with a history of major bleeding).

IDO1 suppresses inhibitor development in hemophilia A treated with factor VIII

The development of inhibitory antibodies to factor VIII (FVIII) is a major obstacle in using this clotting factor to treat individuals with hemophilia A. Patients with a congenital absence of FVIII do not develop central tolerance to FVIII, and therefore, any control of their FVIII-reactive lymphocytes relies upon peripheral tolerance mechanisms. Indoleamine 2,3-dioxygenase 1 (IDO1) is a key regulatory enzyme that supports Treg function and peripheral tolerance in adult life. Here, we investigated the association between IDO1 competence and inhibitor status by evaluating hemophilia A patients harboring F8-null mutations that were either inhibitor negative (n = 50) or positive (n = 50). We analyzed IDO1 induction, expression, and function for any relationship with inhibitor occurrence by multivariable logistic regression and determined that defective TLR9-mediated activation of IDO1 induction is associated with an inhibitor-positive status. Evaluation of experimental hemophilic mouse models with or without functional IDO1 revealed that tryptophan metabolites, which result from IDO1 activity, prevent generation of anti-FVIII antibodies. Moreover, treatment of hemophilic animals with a TLR9 agonist suppressed FVIII-specific B cells by a mechanism that involves IDO1-dependent induction of Tregs. Together, these findings indicate that strategies aimed at improving IDO1 function should be further explored for preventing or eradicating inhibitors to therapeutically administered FVIII protein.

Association between the metabolic syndrome, its individual components, and unprovoked venous thromboembolism: results of a patient-level meta-analysis

OBJECTIVE

The metabolic syndrome (MetS) may contribute to the pathogenesis of venous thromboembolism (VTE), but this association requires additional investigation.

APPROACH AND RESULTS

We performed a patient-level meta-analysis of case-control and cohort studies that evaluated the role of MetS and risk of unprovoked VTE. For case-control studies, odds ratios and 95% confidence intervals were calculated using logistic regression analysis to estimate the influence of individual variables on the risk of VTE; χ(2) tests for trend were used to investigate the effect of increasing number of components of MetS on the risk of VTE and to explore the influence of abdominal obesity on this relationship. For cohort studies, hazard ratios and 95% confidence interval were calculated using multivariable Cox regression analysis. Six case-control studies were included (908 cases with unprovoked VTE and 1794 controls): in multivariate analysis, MetS was independently associated with VTE (odds ratio, 1.91; 95% confidence interval, 1.57-2.33), and both MetS and abdominal obesity were better predictors of unprovoked VTE than obesity defined by the body mass index. Two prospective cohort studies were included (26,531 subjects and 289 unprovoked VTE events): age, obesity, and abdominal obesity, but not MetS were associated with VTE.

CONCLUSIONS

Case-control but not prospective cohort studies support an association between MetS and VTE. Abdominal adiposity is a strong risk factor for VTE.

Acquired inhibitors of coagulation factors: part I-acquired hemophilia A

Acquired hemophilia A (AHA) is a rare, but often severe, bleeding disorder caused by autoantibodies against clotting factor VIII (FVIII). AHA occurs more frequently in the elderly and in association with several conditions, such as malignancies, autoimmune diseases, postpartum, or drug exposure; however, about half of the cases remain idiopathic. At variance with congenital hemophilia, where hemarthroses are the most common bleeding symptoms, hemorrhages in AHA involving soft tissues (muscle, skin) are more frequently reported. AHA is diagnosed in patients: with negative personal or family bleeding history; in which prolonged activated partial thromboplastin time is not corrected after mixing and incubating equal volumes of patient and normal plasma for ~2 hours at 37°C; FVIII levels are reduced; and a specific FVIII-inhibiting activity is detected. Prompt recognition and treatment of AHA are mandatory, as inadequate management and complications of the disease are associated with high mortality rates. Therapeutic approaches should aim to control acute bleeds, eradicate FVIII-autoantibody production, treat associated diseases, and when possible, eliminate them. Present knowledge about this often overlooked and challenging condition has significantly increased following establishment of recent national and international studies, as will also be reviewed in this article.

Glanzmann's thrombasthenia (defective platelet integrin alphaIIb-beta3): proposals for management between evidence and open issues

Glanzmann's Thrombasthenia (GT) is a rare autosomal recessive bleeding disorder, characterized by a quantitative or qualitative defect of platelet surface alpha(IIb)-beta(3) integrin. Presently, no specific guideline/algorithm for clinical management for GT is available. Due to the rarity and heterogeneity of inherited platelet abnormalities, recommendations and guidelines are based on reports from opinions and clinical experience of panel of experts, and refer to the general management of platelet disorders. Based on the limited evidence in the area and on the strategies in clinical settings of inherited/acquired platelet defects, proposals for management of minor bleeding, moderate/major bleeding unresponsive to conservative management, major surgery, minor surgery and dental procedures for GT patients without, or with anti-platelet isoantibodies are reported. In addition to life-style advices and continuous patient education programs, when and how to employ/combine local measures, antifibrinolytic agents, hormone treatment, platelet transfusions and recombinant activated Factor VII is described. The prospective collection of treatments in GT patients recently established (Glanzmann's Thrombasthenia Registry, GTR), based on a careful definition of clinical settings and outcomes, is likely to provide newer insight for optimising clinical management in GT.

Increased troponin I predicts in-hospital occurrence of hemodynamic instability in patients with sub-massive or non-massive pulmonary embolism independent to clinical, echocardiographic and laboratory information

INTRODUCTION

Whether in patients with acute central sub-massive or non-massive pulmonary embolism, mild troponin I increase (>0.03 mug/L) predicts in-hospital occurrence of hemodynamic instability and death independent to prognostically relevant clinical, laboratory and echocardiographic information is not fully established.

METHODS AND RESULTS

We evaluated consecutively patients admitted to the Emergency Room for pulmonary embolism; those in stable hemodynamics in whom central pulmonary embolism was confirmed by spiral-computed tomography were recruited. All participants underwent standardized study protocol, including clinical and diagnostic evaluation for assessment of severity of pulmonary embolism; therapy was established accordingly; troponin I was measured, but treatment protocol was not affected by knowledge of troponin I levels. Of 90 patients enrolled in the study, 33 (37%) developed hemodynamic instability during hospitalization (on average, 90 h +/-20 from admission). Troponin I was >0.03 microg/L in 56% of the study population at admission, and predicted occurrence of hemodynamic instability during hospitalization (adjusted hazard ratio 9.8, 95% confidence interval 1.2-79.2), independent to age, gender, co-morbidity, systolic blood pressure, CK-MB, echocardiographic right ventricular dysfunction and other covariates. Twelve patients died during hospitalization (mean time to event 107 h +/-24 from admission); troponin I >0.03 microg/L predicted mortality in univariate analysis, but not after accounting for age, sex and clinical variables. Nevertheless, higher troponin as continuous variable correlated with higher likelihood of in-hospital death (adjusted likelihood ratio 2.2/microg/L, 95% confidence interval 1.1-4.3) in multivariate analysis. In a further multivariate model, CK-MB predicted mortality independent of covariates and troponin I.

CONCLUSIONS

In patients with acute central sub-massive or non-massive pulmonary embolism, even mild increase in troponin I >0.03 microg/L may provide relevant short-term prognostic information independent to clinical, laboratory and echocardiographic data.