Telomere length in human liver diseases

Abstract: To determine the role of telomere-mediated gene stability in hepatocarcinogenesis, we examined the telomere length of human liver with or without chronic liver diseases and hepatocellular carcinomas (HCC). The mean telomere restriction fragment (TRF) length of normal liver (n=13), chronic hepatitis (n=11), liver cirrhosis (n=24) and HCC (n=24) was 7.8±0.2, 7.1±0.3, 6.4±0.2 and 5.2±0.2 kb, respectively (mean±standard error). TRF length decreased with a progression of chronic liver diseases and that in HCC was significantly shorter than that in other chronic liver diseases (p<0.05). The ratios of TRF length of HCC to that of corresponding surrounding liver of well differentiated (n=7), moderately differentiated (n=10) and poorly differentiated (n=4) HCCs were 0.83±0.06, 0.75±0.05 and 0.98±0.09, respectively. The ratio of poorly differentiated HCC was significantly higher than that of moderately differentiated HCC (p<0.05). A comparison between the size and telomere length ratio of moderately differentiated HCCs revealed a decrease of the ratio with size until it reached 50 mm in diameter. In contrast, the ratio increased as the size enlarged over 50 mm. These findings suggest that the gene stability of the liver cells mediated by the telomere is reduced as chronic liver disease progresses and that telomerase is activated in poorly differentiated HCC and moderately differentiated HCC over 50 mm in diameter.     

Analysis of telomere length in mantle cell lymphoma

Mantle cell lymphoma (MCL) is a well defined lymphoid neoplasm genetically characterized by the t(11;14)(q13;q32). Telomeres play an essential role in preserving chromosomal integrity and genomic stability; their shortening can lead to telomere dysfunction and chromosomal instability, a critical factor in cancer development. In this study, telomere length (TL) measured by terminal restriction fragments (TRF) assay in DNA samples of tumor cells from 20 patients with MCL was evaluated. Results were correlated with clinical, morphologic and cytogenetic characteristics. In all cases, the presence of the CCND1/IGH@ rearrangement was confirmed by fluorescence in situ hybridization and/or PCR analysis. TL in total MCL patients revealed a mean TRF value (4.51 ± 0.79 kb) significantly shorter than those observed in controls (7.49 ± 1.94 kb) (P < 0.001); 30% of patients had TL shorter than 4.0 kb. TRF length was not associated with patients age (P = 0.07; r = 0.17) nor with sex (females: 4.33 ± 0.51 kb and males: 4.57 ± 0.85 kb; P = 0.63). No significant differences were found between patients studied at diagnosis (13) (4.44 ± 0.81 kb) respect to those analyzed at relapse (7) (4.63 ± 0.82 kb) (P = 0.53). In addition, we compared patients with (4.84 ± 1.09 kb) and without (4.40 ± 0.68 kb) complex karyotypes (P = 0.45) and cases with typical morphology (4.48 ± 0.79 kb) vs. blastoid variant (4.63 ± 1.04 kb) (P = 0.83), and no significant differences between them were found. Although the number of cases of our series is not large, our results showed that TL reduction in MCL is independent of the clinical characteristics, morphology and karyotype.     

Telomere attrition is associated with inflammation, low fetuin-A levels and high mortality in prevalent haemodialysis patients

Introduction. Chronic kidney disease (CKD) predisposes to a 10- to 20-fold increased cardiovascular risk. Patients undergo accelerated atherogenesis and vascular ageing. We investigated whether telomere attrition, a marker of cell senescence, contributes to this increased mortality risk. Methods. This is a cross-sectional study in prevalent haemodialysis patients [n = 175; 98 Males; median (range) age: 66 (23–86) years]. Biochemical markers of oxidative stress and inflammatory status were measured in relation to the patient’s leucocyte telomere length. Overall mortality was assessed after a median of 31 (range 2–42) months. Results. Telomere length was shorter in CKD men, despite women being older (average ± SD 6.41 ± 1.23 vs. 6.96 ± 1.48 kb, P = 0.002). Telomere length was associated with age (rho = −0.18, P = 0.01), fetuin-A (rho = 0.26, P = 0.0004), high-sensitivity C-reactive protein (rho = −0.21, P = 0.005) and IL-6 (rho = −0.17, P = 0.02). In a multivariate logistic regression (pseudo r² = 0.14), telomere length was associated with age >65 years (odds ratio: 2.11; 95% CI: 1.10, 4.06), sex (2.01; 1.05, 3.86), fetuin-A (1.85; 0.97, 3.50) and white blood cell count (2.04; 1.02, 4.09). Receiver operating characteristic curves identified a telomere length < 6.28 kb as a fair predictor of mortality. Finally, reduced telomere length was associated with increased mortality, independently of age, gender and inflammation (likelihood ratio 41.6, P < 0.0001), but dependently on fetuin-A levels. Conclusion. Age and male gender seem to be important contributors to reduced telomere length in CKD patients, possibly via persistent inflammation. Reduced telomere length also contributes to the mortality risk of these patients through pathways that could involve circulating levels of fetuin-A.     

Short telomere length is associated with NOTCH1/SF3B1/TP53 aberrations and poor outcome in newly diagnosed chronic lymphocytic leukemia patients

Most previous studies on telomere length (TL) in chronic lymphocytic leukemia (CLL) are based on referral cohorts including a high proportion of aggressive cases. Here, the impact of TL was analyzed in a population‐based cohort of newly diagnosed CLL (n = 265) and in relation to other prognostic markers. Short telomeres were particularly associated with high‐risk genetic markers, such as NOTCH1, SF3B1, or TP53 aberrations, and predicted a short time to treatment (TTT) and overall survival (OS) (both P < 0.0001). TL was an independent prognostic factor and subdivided patients with otherwise good‐prognostic features (e.g., mutated IGHV genes, favorable cytogenetics) into subgroups with different outcome. Furthermore, in follow‐up samples (n = 119) taken 5–8 years after diagnosis, TL correlated well with TL at diagnosis and remained unaffected by treatment. Altogether, these novel data indicate that short TL already at diagnosis is associated with poor outcome in CLL and that TL can be measured at later stages of the disease. Am. J. Hematol. 88:647–651, 2013. © 2013 Wiley Periodicals, Inc.     

Telomere dysfunction accurately predicts clinical outcome in chronic lymphocytic leukaemia,even in patients with early stage disease

Defining the prognosis of individual cancer sufferers remains a significant clinical challenge. Here we assessed the ability of high‐resolution single telomere length analysis (STELA), combined with an experimentally derived definition of telomere dysfunction, to predict the clinical outcome of patients with chronic lymphocytic leukaemia (CLL). We defined the upper telomere length threshold at which telomere fusions occur and then used the mean of the telomere ‘fusogenic’ range as a prognostic tool. Patients with telomeres within the fusogenic range had a significantly shorter overall survival (P < 0·0001; Hazard ratio [HR] = 13·2, 95% confidence interval [CI] = 11·6–106·4) and this was preserved in early‐stage disease patients (P < 0·0001, HR=19·3, 95% CI = 17·8–802·5). Indeed, our assay allowed the accurate stratification of Binet stage A patients into those with indolent disease (91% survival at 10 years) and those with poor prognosis (13% survival at 10 years). Furthermore, patients with telomeres above the fusogenic mean showed superior prognosis regardless of their IGHV mutation status or cytogenetic risk group. In keeping with this finding, telomere dysfunction was the dominant variable in multivariate analysis. Taken together, this study provides compelling evidence for the use of high‐resolution telomere length analysis coupled with a definition of telomere dysfunction in the prognostic assessment of CLL.     

Disrupted lymphocyte homeostasis in hepatitis‐associated acquired aplastic anemia is associated with short telomeres

Hepatitis‐associated aplastic anemia (HAA) is a variant of acquired aplastic anemia (AA) in which immune‐mediated bone marrow failure (BMF) develops following an acute episode of seronegative hepatitis. Dyskeratosis congenita (DC) is an inherited BMF syndrome characterized by the presence of short telomeres, mucocutaneous abnormalities, and cancer predisposition. While both conditions may cause BMF and hepatic impairment, therapeutic approaches are distinct, making it imperative to establish the correct diagnosis. In clinical practice, lymphocyte telomere lengths (TL) are used as a first‐line screen to rule out inherited telomeropathies before initiating treatment for AA. To evaluate the reliability of TL in the HAA population, we performed a retrospective analysis of TL in 10 consecutively enrolled HAA patients compared to 19 patients with idiopathic AA (IAA). HAA patients had significantly shorter telomeres than IAA patients (P = 0.009), including four patients with TL at or below the 1st percentile for age‐matched controls. HAA patients had no clinical features of DC and did not carry disease‐causing mutations in known genes associated with inherited telomere disorders. Instead, short TLs were significantly correlated with severe lymphopenia and skewed lymphocyte subsets, features characteristic of HAA. Our results indicate the importance of caution in the interpretation of TL measurements in HAA, because, in this patient population, short telomeres have limited specificity. Am. J. Hematol. 91:243–247, 2016. © 2015 The Authors. American Journal of Hematology Published by Wiley Periodicals, Inc.     

Telomere length is an independent prognostic marker in MDS but not in de novo AML

Telomere dysfunction is implicated in the generation of large‐scale genomic rearrangements that drive progression to malignancy. In this study we used high‐resolution single telomere length analysis (STELA) to examine the potential role of telomere dysfunction in 80 myelodysplastic syndrome (MDS) and 95 de novo acute myeloid leukaemia (AML) patients. Despite the MDS cohort being older, they had significantly longer telomeres than the AML cohort (P < 0·0001) where telomere length was also significantly shorter in younger AML patients (age <60 years) (P = 0·02) and in FLT3 internal tandem duplication‐mutated AML patients (P = 0·03). Using a previously determined telomere length threshold for telomere dysfunction (3·81 kb) did not provide prognostic resolution in AML [Hazard ratio (HR) = 0·68, P = 0·2]. In contrast, the same length threshold was highly prognostic for overall survival in the MDS cohort (HR = 5·0, P < 0·0001). Furthermore, this telomere length threshold was an independent parameter in multivariate analysis when adjusted for age, gender, cytogenetic risk group, number of cytopenias and International Prognostic Scoring System (IPSS) score (HR = 2·27, P < 0·0001). Therefore, telomere length should be assessed in a larger prospective study to confirm its prognostic role in MDS with a view to integrating this variable into a revised IPSS.     

A prospective study of contrast preservation using ultra-low contrast delivery technique versus standard automated contrast injector system in coronary procedures

BackgroundWe aimed to assess the decrease in contrast media volume (CMV) with ultra-low contrast delivery technique (ULCD) developed at our institution versus the usual automated contrast injector system (ACIS) contrast delivery in coronary procedures.MethodsWe analyzed the amount of contrast given in the consecutive 204 patients of the operators who use ULCD technique versus consecutive 200 patients of the other operators who use ACIS without ULCD technique for coronary angiograms and/or percutaneous coronary interventions (PCIs) from May 2017 to July 2018 at our center. We calculated the mean CMV between these groups.ResultsWe observed a significant reduction in mean CMV with ULCD technique versus standard ACIS, respectively: angiogram 24.8 ± 15.8 mL (n = 194) vs 42.3 ± 25.1 mL (n = 200) (p < 0.0001); PCI 23.5 ± 19.7 mL (n = 52) vs 48.2 ± 30.8 mL (n = 16) (p < 0.0070); angiogram with ad hoc PCI 53.4 ± 32.1 mL (n = 23) vs 89.7 ± 35.6 mL (n = 16) (p < 0.0024); and overall angiogram and PCI 27.4 ± 20.5 mL (n = 204) vs 44.9 ± 28.0 mL (n = 181) (p < 0.0001).ConclusionOur study showed a highly significant reduction in CMV using ULCD technique compared to standard ACIS contrast delivery in coronary invasive procedures. Even in the standard ACIS arm, CMV was significantly lower than values reported in literature, possibly due to operators' bias toward contrast preservation.     

Evidence for Impaired Pancreatic Beta Cell Function in South African Indians with Impaired Glucose Tolerance

In a prospective study of South African Indians with impaired glucose tolerance (IGT), the serum insulin response during a 75 g oral glucose tolerance test (OGTT) was examined in 128 subjects who were classified as IGT 1 year previously (year 0) and in 60 matched control subjects. Based on the results at year 1, study subjects were divided into three groups, using World Health Organization criteria for glucose tolerance: IGT (n = 47), diabetes (n = 41), and transient IGT (normal glucose tolerance) (n = 40). When compared with the control group, despite higher plasma glucose concentrations, the IGT group showed similar fasting insulin, but lower 30-min insulin response (57.4 ± 1.9 mUI^?1 vs 86.5 ± 1.8, p<0.001) and lower 30-min insulin/glucose ratio (7.4 ± 5.2 vs 13.3 ± 8.7, p < 0.001). The insulinogenic index was lower in the IGT group than in the control group at 30, 60, 90, and 120 min (p < 0.01, p < 0.001, p < 0.001, p < 0.001, respectively). The 2-h insulin response was higher in the IGT group (106.7 ± 1.9 mUI^?1 vs 59.2 ± 1.9, p < 0.01). The IGT group displayed a delayed pattern of insulin response with maximum levels only at 2-h. Insulin area was similar in the two groups. In the transient IGT group, despite similar plasma glucose levels, the insulin responses at 0, 15, 30, and 60 min (p < 0.01, p < 0.001, p < 0.001, p < 0.001, respectively) were lower than in the control group; the 30-min insulin/glucose ratio (7.1 ± 5.1 vs 13.3 ± 8.7, p < 0.001) and 60-min insulinogenic index (46.9 ± 86.3 vs 123.4 ± 206.3, p < 0.001) were also lower in the transient IGT group. This study has shown that IGT in South African Indians is characterized by a diminished early phase insulin response and delayed (2-h) hyperinsulinaemia during OGTT. Such findings would suggest that in this population group impaired early beta cell function is an important pathophysiological abnormality underlying IGT.     

Insulin Deficiency Rather Than Hyperinsulinaemia in Newly Diagnosed Type 2 Diabetes Mellitus

This paper reports beta cell function as assessed during OGTT using specific IRMAs for insulin, intact and 32/33 split proinsulin in subjects with newly diagnosed Type 2 diabetes matched to normal controls. The relationships between insulin and the proinsulins to risk factors for cardiovascular disease were also examined. Similar fasting insulin concentrations but lower 30-min post-glucose-load insulin concentrations were found in diabetic subjects (mean ± SEM 143 ± 12 pmol^?1 vs 304 ± 19 (p < 0.001). Subjects with diabetes had increased fasting intact (10.6 ± 1.1 pmol^?1 vs 3.3 ± 0.2, p < 0.001) and 32/33 split proinsulin concentrations (8.1 ± 0.9 pmol^?1 vs 2.2 ± 0.3, p < 0.0001). Beta cell dysfunction, as expressed by a reduction in the 30-min insulin to glucose ratio (9.4 ± 1 vs 34.8 ± 2.3, p < 0.0001) and an increase in the fasting percentage of total proinsulin-like to total insulin-like molecules (24.5 ± 9% vs 11.6 ± 5, p < 0.001), was present in subjects with diabetes. In diabetic subjects beta cell dysfunction and insulin deficiency increased relative to the degree of fasting hyperglycaemia. It seems clear that beta cell dysfunction and insulin deficiency are major features of Type 2 diabetes. Only the fasting concentration of 32/33 split proinsulin positively correlated with both the waist/hip ratio (r = 0.36, p < 0.001), diastolic blood pressure (r = 0.23, p < 0.01) in addition to plasma triglyceride concentration (r = 0.46, p < 0.001). It is questionable whether hyperinsulinaemia plays a pathogenic role in cardiovascular disease in subjects with glucose intolerance.     

The Role of microsomal triglyceride transfer protein and dietary cholesterol in chylomicron production in diabetes

Aims/hypothesis. The aim of this study was to examine factors involved in chylomicron production in the streptozotocin diabetic rat, our hypothesis being that the synthesis of the chylomicron is abnormal in diabetes. Methods. Diabetic rats (n = 20) were paired with control rats (n = 20). Cholesterol emulsion was given by gavage and the lymph duct was cannulated. Lymph was collected for 4 h. Chylomicrons were prepared from the lymph by ultracentrifugation. Lymph apolipoprotein B48 was isolated by gradient gel electrophoresis and quantified by densitometric scanning. Intestinal microsomal triglycerol transfer protein mRNA was measured by solution hybridisation nuclease protection, using a rat specific [³²P]-labelled cRNA probe. Results. Serum triglyceride and cholesterol were greatly increased in diabetic compared with control animals (258 ± 77 and 8.9 ± 6.4 mg/ml vs 1.04 ± 0.37 and 0.54 ± 0.03 mg/ml, p < 0.0001). Lymph chylomicron triglyceride and cholesterol were also higher in diabetic rats (29.4 ± 27.3 and 0.28 ± 0.3 mg/h vs 16.8 ± 10.6 and 0.18 ± 0.09 mg/h, p < 0.05). Lymph chylomicron apo B48 was similar in the two groups. Intestinal microsomal triglycerol transfer protein mRNA was higher in the diabetic rats (12.6 ± 3.2 vs 3.8 ± 3.0 amol/μg RNA, p < 0.0001) and there was a positive correlation between lymph triglyceride and microsomal triglycerol transfer protein mRNA in the whole group (r = 0.65, p < 0.01). Conclusion/interpretation. The study shows that microsomal triglycerol transfer protein mRNA is raised in diabetes without an increase in apolipoprotein B48 in the lymph suggesting that microsomal triglycerol transfer protein regulates chylomicron triglyceride content but not particle number. [Diabetologia (1999) 42: 944–948] Received: 9 December 1998 and in revised form: 6 April 1999     

Antioxidant treatment of experimental diabetic retinopathy in rats with nicanartine

Summary In order to study the contribution of oxidant stress to the pathogenesis of experimental diabetic retinopathy, male streptozotocin diabetic Lewis rats were treated with the antioxidant and lipid-lowering compound nicanartine (80 mg/kg; n = 8, blood glucose level 16.7 ± 3.9 mmol/l; HbA₁ 11.8 ± 1.6 %) by oral supplementation for 6 months and compared with untreated diabetic (n = 6; blood glucose 18.1 ± 1.4 mmol/l; HbA₁ 11.5 ± 1.5 %) and untreated, non-diabetic rats (n = 8; blood glucose 4.0 ± 0.6 mmol/l; HbA₁ 4.8 ± 0.9 %). Diabetic retinopathy was evaluated by computer-assisted quantitative morphometry including measurement of autofluorescent advanced glycated end-products and immunohistochemistry for heme oxygenase I. Antioxidant treatment did not inhibit the 3.1-fold increase of retinal advanced glycation end products, while the expression of heme oxygenase I in both vascular and glial structures was markedly reduced. Chronic hyperglycaemia led to a 37.3 % increase in endothelial cells (p < 0.001 vs normal controls) and a 26.6 % reduction in pericyte numbers (p < 0.001 vs controls). Both abnormalities were significantly ameliorated by nicanartine (p < 0.001 vs diabetic controls). No effect was observed on the formation of acellular capillaries or microaneurysms. These data indicate that antioxidant therapy with nicanartine is of limited benefit in diabetic retinopathy, at least in the rodent model of streptozotocin-induced diabetes. [Diabetologia (1997) 40: 629–634] Received: 19 December 1996 and in revised form: 20 February 1997     

Telomere length is a critical determinant for survival in multiple myeloma

The variable clinical outcomes of Multiple Myeloma (MM) patients are incompletely defined by current prognostication tools. We examined the clinical utility of high‐resolution telomere length analysis as a prognostic marker in MM. Cohort stratification, using a previously determined length threshold for telomere dysfunction, revealed that patients with short telomeres had a significantly shorter overall survival (P < 0·0001; HR = 3·4). Multivariate modelling using forward selection identified International Staging System (ISS) stage as the most important prognostic factor, followed by age and telomere length. Importantly, each ISS prognostic subset could be further risk‐stratified according to telomere length, supporting the inclusion of this parameter as a refinement of the ISS.     

The Effect of the Phytoestrogen Genistein on Myocardial Protection, Preconditioning and Oxidative Stress

Introduction We have previously shown that estrogen administered in ovariectomized female rabbits significantly reduce myocardial infarct size. We now investigated whether the phytoestrogen genistein similarly protects ischemic myocardium and whether this is associated with its antioxidant properties. In addition, we examined whether genistein abolishes preconditioning, since at high doses, it inhibits tyrosine kinase. Materials and methods We studied five groups of New Zealand white female rabbits. Group A (n = 12) were normal controls, group B (n = 14) were ovariectomized 4 weeks prior to the experiment, group C (n = 10) were ovariectomized and treated with genistein (0.2 mg kg⁻¹ day⁻¹ subcutaneously) for 4 weeks before the experiment, group D (n = 12) had intact gonads and were treated with genistein (0.2 mg kg⁻¹ day⁻¹ subcutaneously) for 4 weeks before the experiment and group E (n = 8) were ovariectomized 4 weeks prior to the experiment and treated with a single dose of genistein (0.2 mg kg⁻¹ day⁻¹ subcutaneously) just prior to the experiment. All animals underwent 30 min of heart ischemia and 120 min of reperfusion, with (subgroup I) or without (subgroup II) preconditioning. Malondialdehyde (MDA) concentration just before the experiment was determined. Results We found significant differences between the groups—p < 0.0001 in factorial ANOVA. The groups with preconditioning had significant smaller infarcts compared to those without—AI vs AII (10.66 ± 1.42% vs 43.22 ± 2.67%), BI vs BII (18.53 ± 2.36% vs 43.05 ± 8.37%), CI vs CII (10.17 ± 2.07% vs 44.5 ± 5.47%), DI vs DII (14.98 ± 2.36% vs 37.79 ± 3.92%) and EI vs EII (17.11 ± 3.24% vs 42.08 ± 3.42%), p < 0.0005. Ovariectomy was not associated with larger myocardial infarctions—AII vs BII, p = NS. Genistein, for 4 weeks, did not protect ischemic myocardium in either ovariectomized or non-ovariectomized animals—BII vs CII and AII vs DII, p = NS. There was no significant difference between the preconditioned animals, with intact gonads or ovariectomized (AI vs BI, p = NS), ovariectomized with or without genistein (BI vs CI, p = NS) and non-ovariectomized whether treated with genistein or not (AI vs DI, p = NS). A single dose of genistein did not offer any protection (EII vs BII, p = NS), nor did it modify the preconditioning effect (EI vs BI, p = NS). We found no significant difference in MDA plasma levels between the groups. Conclusion Genistein, at this dose, does not reduce infarct size per se nor abolishes the protection induced by preconditioning, in both ovariectomized and non-ovariectomized animals. Preconditioning offers myocardial protection in animals with intact gonads as well as estrogen deprived; bilateral ovariectomy, at least during short-term, is not associated with larger myocardial infarcts compared to control animals. In addition estrogen deprivation, during short term, as well as genistein do not modify oxidative stress.     

Association of Erythrocyte Aldose Reductase Activity with Diabetic Complications in Type 1 Diabetes Mellitus

Erythrocyte aldose reductase was isolated and its activity measured in 72 Type 1 (insulin dependent) diabetic patients and 21 age and sex matched non-diabetic subjects. The diabetic patients were categorized into two groups in terms of presence (n = 29) or absence (n = 43) of severe diabetic complications. Age, sex, duration of diabetes and HbA_1c levels were matched between the diabetic groups. Erythrocyte aldose reductase (mean ± SEM) was increased in patients with Type 1 diabetes compared to the non-diabetic subjects (7.22 ± 0.24 vs 5.66 ± 0.19 Ul-erythrocytes^-1, < 0.0001). There was a four-fold variation in its activity among the diabetic patients (3.38-12.23 Ul-erythrocytes^-1). The enzyme activity was significantly higher in patients with complications than those without (8.17 ± 0.39 vs 6.58 ± 0.26 Ul-erythrocytes^-1, p < 0.002). When the patients were stratified by duration of the disease, the enzyme activity was highest in patients who had developed complications with a duration of less than 20 years and lowest in those without complications for 20 years or longer (8.54 ± 0.48 vs 6.46 ±p± 0.33 Ul-erythrocytes^-1, p < 0.002). Patients who had an aldose reductase activity greater than the mean + 2SD of that seen in non-diabetic controls were four times more likely to have diabetic complications than those whose enzyme activity fell within 2SD of non-diabetic individuals (p < 0.0005). We conclude that the activity of aldose reductase varies among Type 1 diabetic patients and the differences in its activity may result in a variable susceptibility of these patients to the complications of the disease.     

Coagulation Activation in Type 2 Diabetes Mellitus: the Higher Coronary Risk of Female Diabetic Patients

Thrombophilia in diabetic patients is a well-recognized phenomenon which constitutes an additional risk of coronary heart disease. This study included 1980 ethnic Chinese people (835 male, 1145 female); age range: 45 to 69 years, including 280 Type 2 diabetic patients (male 125, female 155). Haemostatic parameters measured were fibrinogen, prothrombin time, activated partial thromboplastin time (APTT), factor VIIc, factor VIIIc, antithrombin III, and plasminogen. Compared with a control group, male diabetic patients showed significantly shorter APTT (25.6 ± 3.7 vs 27.5 ± 3.6 s, p<0.001), and elevated factor VIIIc (171.1 ± 77.48 vs 131.16 ± 52.23%, p<0.0001), whereas female diabetic patients showed significantly shorter APTT (24.9 ± 4.2 vs 26.5 ± 3.9 s, p<0.001) and elevated fibrinogen (10.6 ± 3.3 vs 9.8 ± 2.6 μmol 1^?1, p<0.05), factor VIIc (150.4 ± 68.7 vs 135.3 ± 32.3%, p<0.001), factor VIIIc (190.1 ± 92.6 vs 141.1 ± 62.4%, p<0.0001), and plasminogen (140.3 ± 41.9 vs 128.4 ± 38.7%, p<0.01). This study showed that Chinese diabetic patients had coagulation activation, and that female diabetic patients seemed to constitute a higher risk group for coronary heart disease than males.     

The genetic abnormality in the beta cell determines the response to an oral glucose load

Aims/hypothesis: We assessed how the role of genes genetic causation in causing maturity-onset diabetes of the young (MODY) alters the response to an oral glucose tolerance test (OGTT). Methods: We studied OGTT in 362 MODY subjects, from seven European centres; 245 had glucokinase gene mutations and 117 had Hepatocyte Nuclear Factor –1 alpha (HNF-1α) gene mutations. Results: BMI and age were similar in the genetically defined groups. Fasting plasma glucose (FPG) was less than 5.5 mmol/l in 2 % glucokinase subjects and 46 % HNF-1 α subjects (p < 0.0001). Glucokinase subjects had a higher FPG than HNF-1 α subjects ([means ± SD] 6.8 ± 0.8 vs 6.0 ± 1.9 mmol/l, p < 0.0001), a lower 2-h value (8.9 ± 2.3 vs 11.2 ± 5.2 mmol/l, p < 0.0001) and a lower OGTT increment (2-h – fasting) (2.1 ± 2.3 vs 5.2 ± 3.9 mmol/l, p < 0.0001). The relative proportions classified as diabetic depended on whether fasting (38 % vs 22 %, glucokinase vs HNF-1 α) or 2-h values (19 % vs 44 %) were used. Fasting and 2-h glucose values were not correlated in the glucokinase subjects (r = –0.047, p = 0.65) but were strongly correlated in HNF-1 α subjects (r = 0.8, p < 0.001). Insulin concentrations were higher in the glucokinase subjects throughout the OGTT. Conclusion/interpretation: The genetic cause of the beta-cell defect results in clear differences in both the fasting glucose and the response to an oral glucose load and this can help diagnostic genetic testing in MODY. OGTT results reflect not only the degree of hyperglycaemia but also the underlying cause. [Diabetologia (2002) 45: 427–435] Received: 13 September 2001 and in revised form: 26 November 2001     

Protein C activation in NIDDM patients

Summary Enhanced activation of the clotting system has been recently implicated in the pathogenesis of vascular complications in patients with diabetes mellitus. Abnormalities of the anticoagulant system may constitute a potential trigger factor for the haemostatic activation observed in diabetic subjects. The current study aimed to evaluate anticoagulant activity in diabetic patients by assessing the plasma levels of activated protein C-protein C inhibitor complex; and by measuring the anticoagulant response to exogenous thrombomodulin. This study comprised 61 patients (34 men, 27 women) with non-insulin-dependent diabetes mellitus (NIDDM) of whom 22 showed microalbuminuria and 39 normoalbuminuria. Data obtained in 31 non-obese and non-diabetic subjects were available for comparison. The plasma levels of fibrinogen (p < 0.02), prothrombin fragment 1 + 2 (p < 0.05), fibrin monomer (p < 0.0001), protein C antigen (p < 0.005), total protein S antigen (p < 0.02), soluble thrombomodulin (p < 0.005) and soluble E-selectin (p < 0.005) were significantly higher in diabetic patients than in healthy subjects. The plasma level of activated protein C-protein C inhibitor complex (7.4 ± 3.8 vs 3.0 ± 0.4 pmol/l) was significantly higher (p < 0.0001) and the anticoagulant response to exogenous thrombomodulin (23.4 ± 2.6 vs 35.3 ± 3.0 ng/ml) was markedly lower (p = 0.005) in all diabetic patients than in healthy subjects. Cases with microalbuminuria presented low plasma levels of activated protein C-protein C inhibitor complex (5.5 ± 0.6 vs 8.6 ± 0.7 pmol/l, p < 0.05) and significantly decreased values of the anticoagulant response to exogenous thrombomodulin (16.5 ± 2.9 vs 23.4 ± 2.6 %, p = 0.03) as compared to those with normoalbuminuria. The present study suggests that the hyper-coagulable state in NIDDM is associated with an increased activation of protein C but with a poor plasma reactivity to the anticoagulant effect of thrombomodulin. [Diabetologia (1996) 39: 1455–1461] Received: 27 February 1996 and in revised form: 3 June 1996     

Acute lesion extension following pulmonary vein isolation with two novel single shot devices: Pulsed field ablation versus multielectrode radiofrequency balloon

Introduction

Pulsed-field ablation (PFA) and the multielectrode radiofrequency balloon (RFB) are two novel ablation technologies to perform pulmonary vein isolation (PVI). It is currently unknown whether these technologies differ in lesion formation and lesion extent. We compared the acute lesion extent after PVI induced by PFA and RFB by measuring low-voltage area in high-density maps and the release of biomolecules reflecting cardiac injury.

Methods

PVI was performed with a pentaspline catheter (FARAPULSE) applying PFA or with the compliant multielectrode RFB (HELIOSTAR). Before and after PVI high-density mapping with CARTO 3 was performed. In addition, blood samples were taken before transseptal puncture and after post-PVI remapping and serum concentrations of high-sensitive Troponin I were quantified by immunoassay.

Results

Sixty patients undergoing PVI by PFA (n = 28, age 69 ± 12 year, 60% males, 39.3% persistent atrial fibrillation [AF]) or RFB (n = 32, age 65 ± 13 year, 53% males, 21.9% persistent AF) were evaluated. Acute PVI was achieved in all patients in both groups. Mean number of PFA pulses was 34.2 ± 4.5 and mean number RFB applications was 8.5 ± 3 per patient. Total posterior ablation area was significantly larger in PFA (20.7 ± 7.7 cm²) than in RFB (7.1 ± 2.09 cm²; p < .001). Accordingly, posterior ablation area for each PV resulted in larger lesions after PFA versus RFB (LSPV 5.2 ± 2.7 vs. 1.9 ± 0.8 cm², LIPV 5.5 ± 2.3 vs. 1.9 ± 0.8 cm², RSPV 4.7 ± 1.9 vs. 1.6 ± 0.5 cm², RIPV 5.3 ± 2.1 vs. 1.6 ± 0.7 cm,² respectively; p < .001). In a subset of 38 patients, increase of hsTropI was higher after PFA (625 ± 138 pg/mL, n = 28) versus RFB (148 ± 36 pg/mL, n = 10; p = .049) supporting the evidence of larger lesion extent by PFA.

Conclusion

PFA delivers larger acute lesion areas and higher troponin release upon successful PVI than multielectrode RFB-based PVI in this single-center series.